Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070197

Authors: Hellen Njeri Maingi Maingi Ndichu James Ng’ang’a Chege Davis Njuguna Karanja Derrick Noah Sentamu Bruno Enagnon Lokonon Damaris Matoke-Muhia Helena Ngowi Bassirou Bonfoh

Leishmaniasis is an endemic zoonotic disease caused by the protozoan parasite Leishmania and transmitted by infected female phlebotomine sandflies. The World Health Organization (WHO) classifies it among the 20 neglected tropical diseases (NTDs), ranking eighth globally. The disease predominantly affects resource-limited populations in tropical regions. Kenya bears a significant global burden of leishmaniasis, with Baringo County identified as a major endemic area. A cross-sectional survey on knowledge, attitudes, and practices (KAP) was conducted from July 2025 to January 2026 among 135 residents of Baringo South Sub-County using a structured questionnaire. The study evaluated sociodemographic characteristics, disease awareness, perceptions, preventive practices, and treatment-seeking behaviors. Additionally, 12 healthcare professionals were interviewed regarding their diagnostic and treatment capacities. Associations between variables were analyzed using Chi-square tests and multivariate logistic regression. Overall awareness of leishmaniasis was high (94.8%), with KAP scores of 86.7%, 76%, and 77.7%, respectively. Despite this, critical knowledge gaps persisted regarding transmission dynamics, the role of dogs as reservoir hosts, and preventive measures. Significant associations were found for awareness of local cases, recognition of clinical signs, knowledge of vector activity, community control measures, and attitudes toward treatment preferences. Age and education level predicted KAP outcomes. Healthcare practitioners demonstrated technical capacity to diagnose and treat human Leishmania infections, whereas veterinarians lacked awareness of Leishmania infection in dogs, including its diagnosis and treatment. Integration of human, animal, and vector surveillance within a One Health framework is recommended to enhance disease monitoring and control in Baringo County.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070196

Authors: Guillermo Martínez-Carrión Leire Fernández-Ciriza Iosu Razquin María Ángeles del Río-Poza María Eugenia Portillo

Background: Dermatophilus congolensis, a Gram-positive actinomycete, is a well-known animal pathogen but a rare cause of human skin infections. Human dermatophilosis is an infection associated with tropical environments and animal contact that remains frequently underdiagnosed. Case Presentation: We report a case of recurrent folliculitis in a 34-year-old male Muay Thai fighter returning from Thailand to Spain. The patient presented with pustular lesions on his lower limbs following frequent leg shaving and close physical contact during training. Microbiological culture from skin swabs yielded beta-hemolytic colonies, identified as D. congolensis by MALDI-TOF MS. Identification was confirmed through Whole-Genome Sequencing (WGS), which also revealed an absence of antimicrobial resistance genes. Despite the lack of established EUCAST breakpoints, the isolate showed low MICs for most tested antibiotics. The patient was treated with doxycycline, although clinical follow-up was not possible due to travel. Conclusions: This case highlights D. congolensis as an emerging differential diagnosis for persistent folliculitis in travelers and athletes. Our findings suggest a potential horizontal transmission route through contact sports and fomites (e.g., mats) in high-humidity settings.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070195

Authors: Gabriel Bafunyembaka Christian Kinsiona Joody Mafema Emmanuel Irakoze Philbert Furero Christelle Samou Narcisse Elenga

Background: Intestinal parasitic infections are common in tropical settings and may influence immune regulation, allergic responses, and respiratory health. In children with sickle cell disease (SCD), respiratory morbidity is multifactorial, and the contribution of intestinal parasites remains uncertain. This study assessed whether documented intestinal parasitic infections, particularly helminth infections, were associated with asthma-like respiratory phenotypes and clinical morbidity in children with SCD in French Guiana. Methods: We conducted a multicenter cross-sectional analysis of children and adolescents younger than 18 years with confirmed SCD who were being followed by the pediatric SCD centers of Saint-Laurent-du-Maroni, Cayenne, and Kourou between January 2022 and December 2025. Clinical, respiratory, and parasitological data were extracted from routine-care medical records. Intestinal parasitic infection was defined as at least one documented stool parasitology result identifying Strongyloides stercoralis, hookworm, or Entamoeba histolytica, according to the variables consistently available in the database. Respiratory outcomes included physician-diagnosed asthma, bronchial obstruction, bronchodilator reversibility, and an asthma-like respiratory phenotype. Results: Among 233 included children, 105 (45.1%) had at least one documented intestinal parasitic infection and 82 (35.2%) had a helminth infection. Hookworm was the most common parasite (75/233, 32.2%), followed by Entamoeba histolytica (33/233, 14.2%) and Strongyloides stercoralis (24/233, 10.3%). An asthma-like respiratory phenotype was observed in 32/105 infected children (30.5%) versus 44/128 non-infected children (34.4%). Bronchial obstruction and bronchodilator reversibility were also similar between groups. After adjustment for age, sex, genotype, hydroxyurea treatment, rural residence, site of follow-up, and environmental tobacco smoke exposure, intestinal parasitic infection was not associated with asthma-like respiratory phenotype (adjusted OR: 0.94, 95% CI: 0.51–1.72; p = 0.844), recurrent hospitalization, or history of acute chest syndrome. Conclusions: In this routine-care multicenter pediatric SCD cohort from French Guiana, intestinal parasitic infections were common but were not associated with respiratory phenotype or selected morbidity outcomes. Because testing and respiratory assessment were not systematic, these findings should be interpreted as showing that routine parasitological status alone could not identify children with respiratory morbidity. Prospective studies with standardized repeated parasitological, immunological, environmental, and respiratory assessments are needed.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070194

Authors: Aqsa Mansoor Ghulam Narjis Imen Ben Abdelmalek Sabika Firasat Iffat Naz Kiran Afshan

Background: Malaria remains a major public health challenge in Pakistan, where persistent transmission, heterogeneous risk patterns, and evolving treatment practices continue to impede control and elimination efforts. Methods: A community-based cross-sectional study was conducted among 9211 symptomatic individuals in District Dera Ismail Khan, northwestern Pakistan, from January 2024 to December 2025. Malaria was diagnosed using rapid immunochromatographic assays for Plasmodium vivax (P. vivax) and Plasmodium falciparum (P. falciparum), and associated risk factors were assessed using multivariable logistic regression. Results: Overall malaria prevalence was 36.27% (3341/9211). P. vivax predominated, accounting for 93.8% (3133/3341) of infections, while P. falciparum represented 5.8% (195/3341) and mixed infections 0.4% (13/3341). Infection risk was significantly associated based on multivariate analysis with male sex, younger age, pregnancy (AOR = 4.69), and absence of mosquito net use (AOR = 6.17), whereas indoor residual spraying (AOR = 0.08) showed a strong protective effect. Malaria transmission showed two peaks: October–December (AOR = 3.78–4.97) and February–March (AOR = 2.25–2.31) and declined significantly based on unadjusted analysis from 39.5% in 2024 to 32.8% in 2025 (OR = 0.74; p < 0.001). Blood groups B+ (AOR = 0.77), B− (AOR = 0.78), and AB− (AOR = 0.86) were significantly associated with reduced odds of malaria infection. A notable shift toward artemisinin-based combination therapy was observed, with artemether–lumefantrine largely replacing chloroquine for malaria treatment. Conclusions: The persistence of P. vivax-dominated transmission alongside ongoing P. falciparum circulation highlights the need for targeted vector control, enhanced surveillance, and evidence-based treatment strategies to accelerate malaria elimination in Pakistan.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070193

Authors: Oh Beom Kwon Yeonjeong Heo Da Hye Moon Woo Jin Kim Seung-Joon Lee Seon-Sook Han

Tuberculosis (TB) remains a major infectious disease associated with substantial healthcare burdens. Although previous studies mainly focused on mortality and treatment outcomes, factors associated with TB-related hospitalization have not been sufficiently investigated. The aim of our study was to evaluate clinical factors associated with TB-related hospitalization in patients with TB. Patients diagnosed with TB at Kangwon National University Hospital between January 2024 and December 2025 were included in our study. The primary outcome was TB-related hospitalization during follow-up after TB diagnosis. Hospitalization-free probability was analyzed using Kaplan–Meier analysis, and Cox proportional hazards regression analysis was performed to identify factors associated with hospitalization risk. A total of 81 patients were included; 63 patients were in the outpatient group and 18 patients were in the hospitalization group. The median time to hospitalization was 36 days. The Charlson comorbidity index (CCI) was significantly higher in the hospitalization group (5.78 ± 2.88 vs. 4.16 ± 2.22, p = 0.038). Patients with CCI values ≥ 5 showed significantly lower hospitalization-free probability during the 180-day follow-up period (log-rank p = 0.013). In multivariable Cox hazards regression analysis, both serum creatinine (hazard ratio (HR), 1.599; 95% confidence interval (CI), 1.057–2.419; p = 0.026) and CCI (HR, 1.221; 95% CI, 1.018–1.466; p = 0.032) were significantly associated with TB-related hospitalization. A higher comorbidity burden may help identify patients at risk for TB-related hospitalization.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070192

Authors: Bayo Segun Fatunmbi Alexander Yabes Taruc Kazim Hizbullah Sanikullah Anna Marie Celina Garfin Jose Gerard Belimac Almira Cruz Gatchalian Ma. Regina De Jesus Valdez Carmel Angela Buado Kim Patrick Tejano Abelaine Venida-Tablizo Frederica Veronica Marquez-Protacio Belen L. Dofitas Arturo Cunanan Reginald Alain R. Santos Francesca Cando Gajete Concepcion P. Dumawat Eugene Caccam Eunyoung Ko Rui Paulo de Jesus

The Philippines achieved World Health Organization (WHO) certification for the elimination of leprosy as a public health problem in 1998. Despite this milestone, new cases continue to be reported each year, highlighting the need for sustained surveillance and interventions to achieve zero transmission. This paper provides an update on the country’s progress toward interruption of leprosy transmission using national surveillance data and programmatic reports from 2020–2024. Quantitative data were obtained from the Department of Health (DOH) Field Health Services Information System (FHSIS), while policy and programmatic information were drawn from national reports, WHO guidance, and implementation reviews. Descriptive analyses were conducted to examine trends in prevalence, case detection rates (CDRs), and age-sex distribution patterns to identify high-risk groups. Leprosy prevalence declined from 0.41 per 10,000 population in 2020 to 0.11 in 2024, remaining below the WHO elimination threshold. The CDR increased from 0.45 in 2022 to 1.17 per 100,000 in 2024, indicating recovery of active surveillance after COVID-19-related disruptions. Most newly detected cases occurred among adults aged 20–59 years (72%), although continued detection among children aged 0–14 years (6–7%) suggests ongoing transmission in selected endemic areas. Key program strengths include policy integration and WHO-supported surveillance initiatives, while major barriers include stigma, uneven local implementation, and limited access to rehabilitation. The Philippines has maintained low national prevalence while strengthening efforts toward transmission interruption. Continued investment in surveillance, contact tracing, stigma reduction, and integrated neglected tropical disease (NTD) services will be essential to achieving zero transmission, zero disability, and zero discrimination by 2030.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070191

Authors: Nalini Jayakody Catherine A. Gordon Anjana Silva Nuwan Wickramasinghe Susiji Wickramasinghe Natasha Collinson Asela Wijayasekara Chanaka Karunarathne Harshi Weerakoon Manjula Weerasinghe Nilanthi de Silva Kosala Weerakoon

Human intestinal nematode infections (HINIs) remain a public health concern despite reduced prevalence following mass drug administration (MDA) in low- and middle-income countries. Children continue to bear a substantial burden of infection, and caregiver knowledge and practices may influence their risk of acquiring infection. Sustaining control during the transition of prevention programmes to surveillance-based strategies requires an understanding of behavioural determinants of transmission. Therefore, we assessed caregiver knowledge, attitudes, and practices (KAP) and their associations with sociodemographic characteristics and child infection status. A community-based cross-sectional study was conducted among 945 caregivers of primary school children in Anuradhapura, a low-prevalence setting where school-based MDA ceased in 2019, to assess caregiver KAP and child HINI status. An interviewer-administered questionnaire assessed KAP, sociodemographic, water, sanitation, hygiene (WASH), and behavioural factors. Participants were predominantly mothers (89.5%). Good knowledge was observed in 61.7%, positive attitudes in 95.6% and good practices in 99.2%. Knowledge gaps persisted regarding transmission and complications. Higher caregiver knowledge (OR = 0.52; 95% CI: 0.36–0.72) and regular deworming (OR = 0.58, 95% CI: 0.40–0.83) were associated with lower odds of infection, whereas attitudes and practices were not independently associated. Caregiver knowledge remains a key determinant of infection risk. Gaps in knowledge, misconceptions, and practices may sustain transmission even in low-prevalence settings. Strengthening health education, school-based hygiene promotion, and community engagement remains essential to reinforce preventive behaviours and support long-term control as countries transition from routine MDA to elimination-oriented strategies.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070190

Authors: Benjamin Tetteh Mensah Hannah Otu Dorinda Naa Okailey Armah Comfort Teiko Abuanor Lucas Amenga-Etego Samuel Antwi-Baffour

Background: Malaria remains a major public health challenge in sub-Saharan Africa, where asymptomatic infections continue to hinder elimination efforts. Although the clinical and epidemiological consequences of microscopic infections are well documented, the health implications of submicroscopic Plasmodium falciparum infections remain poorly understood, particularly in Ghana. This study assessed the burden of submicroscopic P. falciparum infections and their association with antimalarial drug resistance markers among outpatients attending Korle Bu Teaching Hospital. Methods: A cross-sectional study involving 345 participants was conducted. Malaria infection was assessed using mRDT, blood smear microscopy, and LAMP-PCR for parasite detection and species identification. Antimalarial drug resistance markers were analyzed by multiplex PCR and Oxford Nanopore sequencing. Statistical analysis was performed using STATA version 14, applying Pearson’s chi-square test and logistic regression. Results: The overall prevalence of asymptomatic P. falciparum infection was 35.0% (117/334), with 18.9% microscopic and 16.1% submicroscopic infections. The wild-type pfcrt K76 allele, associated with chloroquine susceptibility, was highly prevalent (90.1%). Conclusions: Asymptomatic P. falciparum infections are common in this population, with a substantial proportion occurring at submicroscopic levels. The high prevalence of chloroquine-susceptible parasites and identified transmission hotspots underscore the need for sensitive diagnostics and targeted interventions to support malaria elimination efforts in Ghana.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070189

Authors: Dan Jiang Kun Wang Shenbo Chen Yang Hong Senping Yang Xiaoyuan Su Yongdong Hao Fei Luo Junhu Chen

This study aimed to project the current and future suitable habitats of three primary malaria vectors in China—An. lesteri, An. minimus, and An. sinensis—using an ensemble modeling approach. We simulated their geographical distributions under current and future climates (SSP126, SSP245, SSP585) using the Biomod2 platform with 19 bioclimatic variables and elevation. The ensemble models achieved high predictive performance, as reflected by AUC and TSS values. Environmental drivers were species-specific: An. lesteri was primarily influenced by elevation, temperature seasonality (Bio4), and seasonal precipitation (Bio18, Bio19); An. minimus by the mean temperature of the coldest quarter (Bio11); and An. sinensis by annual precipitation (Bio12), mean temperature of the wettest quarter (Bio8), and elevation. Future projections revealed divergent responses: the habitat of An. lesteri is projected to contract and shift northeastward; An. sinensis is expected to expand northward, potentially extending climatically suitable areas into new regions; and although the overall range of An. minimus remains stable, its internal suitability shifts toward higher classes under warming. These findings demonstrate that climate change will critically reshape the distribution of major malaria vectors across China, underscoring the need to integrate climate-informed projections into adaptive surveillance and vector control strategies in the post-elimination era.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070188

Authors: Carla Rodríguez González Susana Ávila Karina Cardone Mariana Fernández Favio Crudo Verónica Andreo M. Victoria Periago

Mother-to-child transmission (MTCT) of infectious diseases remains a public health challenge in socially vulnerable regions with limited healthcare access. This study assessed the epidemiological situation, spatial distribution, and socioeconomic context of MTCT infections—Chagas disease (ChD), syphilis, HIV, and hepatitis B (HB)—in the Gran Chaco region (Argentina–Paraguay), 2018–2024. Epidemiological data from 2877 patients enrolled in an MTCT Plus programme were analysed, alongside socioeconomic variables and spatio-temporal cluster analysis using SaTScan software. Maternal seroprevalence of ChD was 4.1%, the highest among the infections evaluated. Syphilis prevalence was 0.8%, while no HIV or HBV infections were detected among screened pregnant women. Two statistically significant spatiotemporal clusters of maternal Trypanosoma cruzi seropositivity were identified: a household-level cluster in 2018 and a regional cluster during 2019–2021. The highest prevalence of maternal ChD seropositivity was observed in census tracts with greater socioeconomic vulnerability, although this spatial overlap was assessed descriptively. These findings highlight the effectiveness of integrated maternal–child health services in ensuring coverage, timely diagnosis, and treatment in vulnerable populations. The identified spatial patterns provide evidence to support targeted surveillance and coordinated binational public health strategies in border regions affected by persistent social inequalities.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070187

Authors: Gregory D. Hawley Chu Sandy Wang Andrea K. Boggild

Marine envenomations are common non-infectious hazards for travelers. Lionfish, venomous fish native to Indo-Pacific waters, have become an invasive species in the Atlantic Ocean and threat to native marine ecosystems. Various control measures have been implemented in response to rapidly expanding lionfish populations, including licensed culling by recreational divers. We herein review lionfish envenomation through framing with a case that occurred during a diving trip to Curacao for the purpose of lionfish spearfishing. Following initial management in Curacao with hot water immersion, wound care, and antibiotic prophylaxis, the patient continued to have persistent swelling, bruising, and pain to the puncture site and was referred to our outpatient clinic for further evaluation. In addition to reviewing clinical syndromes and approach to management for common marine envenomations that may be encountered in the post-travel setting, we situate this case within the broader ecological context of expanding invasive species ranges with climate change and rising sea temperatures. Pre-travel providers should counsel patients at high risk for marine envenomations on preventative measures, along with how and when to seek care following exposure. Post-travel providers should be familiar with the immediate and long-term sequelae of non-infectious envenomations and intoxications, including marine exposures. Larger national and multinational collaborations are required to mitigate the effects of climate change and international marine movement on invasive species, especially those that incur risk to marine and human health alike.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070186

Authors: Haider Saddam Qasim Maree Donna Simpson

Background: Pre-travel health consultations require individualised risk assessment across itinerary, destination, traveller characteristics, vaccine and medication history, comorbidities, pregnancy and immune status, activities, and access to care. Artificial intelligence (AI), particularly large language models (LLMs), may support pre-consultation education, structured history collection, guideline retrieval, multilingual communication and post-consultation reinforcement, but unsafe use may introduce hallucinated, outdated or insufficiently personalised recommendations. Objectives: This scoping review maps the current evidence on AI tools relevant to pre-travel health consultations, characterises implementation gaps, identifies patient-safety risks and proposes a supervised implementation model for travel medicine clinics. Original contribution: Unlike previous reviews of clinical AI, patient-education LLMs or chatbots in chronic illness, this is the first scoping review focused specifically on AI in pre-travel consultations. It uniquely combines a five-tier evidence hierarchy that separates direct travel-medicine AI evidence from indirect clinical-AI safety and equity evidence, and provides a travel-medicine-specific clinical safety risk taxonomy and a supervised implementation framework anchored to authoritative travel-medicine guidance and current AI regulatory regimes. Methods: A scoping review was conducted following PRISMA-ScR reporting, using a Population–Concept–Context eligibility framework and a targeted retrieval in May 2026 covering January 2017 to May 2026. Sources were screened and charted by a single reviewer using a structured eligibility checklist. Quality and applicability were appraised conceptually using MMAT, AMSTAR 2 and JBI text-and-opinion criteria, with GRADE-informed certainty. Results: Of 70 records identified, 11 were included: four direct pre-travel AI sources, one adjacent travel-related decision-support study, four guideline and context sources and two clinical LLM safety sources. The only patient-level implementation involved 26 travellers using a GPT-4 Travel Clinic Assistant in Singapore, where physicians and travellers reported acceptability and workflow benefit but objective effectiveness outcomes were not measured. Broader clinical LLM evidence indicates heterogeneous evaluation methods, vulnerability to hallucinated guidelines, and accuracy that varies widely across model versions and specialties. Conclusions: Current evidence supports supervised AI augmentation of pre-travel consultations but does not support autonomous AI-led vaccine selection, malaria prophylaxis, contraindication screening or individualised travel-risk clearance. Near-term deployment should be restricted to clinician-supervised education, structured intake, source-grounded guideline retrieval, after-visit reinforcement and escalation-triggered workflow support. Priority research includes travel-medicine-specific hallucination audits; equity testing in visiting-friends-and-relatives, migrant, older-adult, First Nations Australian, and Pacific Islander travellers; and prospective trials reported under CONSORT-AI, SPIRIT-AI and TRIPOD + AI.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070185

Authors: Enes Dalmanoğlu İrem Sakarya Ali Osman Yıldız Muhammed Taha Özügüzel Çiğdem Işık Ahmet Enes Kaya Yasin Uslu Vedat Elgün Muhammed Enes Geylani

Background: Human brucellosis is a widespread zoonotic febrile illness in livestock-rearing endemic regions, including Türkiye (pooled human seroprevalence approximately 4.5%). Age-stratified item-level knowledge profiles paired with information-source patterns are rarely reported in adult populations. We aimed to describe age-stratified brucellosis knowledge and information-source ecosystems in a hospital-attending adult sample from an endemic Turkish province. Methods: A hospital-based cross-sectional survey enrolled 397 adults in Balıkesir, Türkiye. A 17-question instrument assessed demographics, prior awareness, a 26-item composite knowledge score among aware respondents, and information sources. Item-level recognition was compared across four age strata, with multivariable logistic regression identifying independent predictors. Results: Of 397 adults (mean age 36.1 years; 62.7% male), 233 (58.7%) reported prior awareness, increasing with age (51.8% in 18–29 vs. 74.5% in ≥60 years; p < 0.001). Among aware respondents, composite knowledge declined with age (mean 8.52 vs. 5.94; p < 0.001). Raw dairy transmission and treatment availability were uniformly recognized (>80% across all strata). Recognition of clinical symptoms (fever 68.9% vs. 34.3%; p = 0.005) and veterinary signs (decreased milk yield 36.9% vs. 8.6%; p = 0.001) was substantially lower in older respondents. Internet citation declined with age (41.7% to 17.1%), while older respondents relied more on interpersonal networks. Conclusions: Brucellosis knowledge was not uniformly distributed across the adult age spectrum. Dominant transmission and treatment messages were near-universally recognized, while clinical-symptom and veterinary-sign recognition showed substantial age-related deficits, accompanied by generational divergence in information-source ecosystems. These findings suggest that age-tailored, channel-specific reinforcement of less-recognized clinical and veterinary knowledge, delivered through trusted healthcare-worker channels, may strengthen brucellosis education in endemic Turkish settings. Community-based replication is required before broader policy translation.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070184

Authors: Yi-Jun Lim Gordon Xue-Zhen Chong Joo-Yie Chin Muhammed-Nur-Iman Mohammed-Syafiei Muhammad-Nasreen Suhaimi Siti-Nursyazziana Nordin Shin-Yee Fung Hazel Anne Tabo Polrat Wilairatana Tadesse Hailu Veeranoot Nissapatorn Wenn-Chyau Lee

Plasmodium knowlesi infections can progress rapidly to life-threatening complications, such as acute respiratory distress syndrome (ARDS) and acute kidney injury (AKI), which are driven by the ability of the zoonotic parasite to rapidly replicate towards high parasitemia and the cytoadherence properties of the infected erythrocytes (IRBCs). This study evaluated the anti-parasitic and vasoprotective potential of Annona muricata (soursop) leaf ethanol extract against P. knowlesi. In vitro assays using the P. knowlesi A1-H.1 reference strain revealed significant blood stage schizogony inhibition (IC50: 9.65 µg/mL), specifically targeting the trophozoites. The anti-parasitic activity was concentrated in the <30 kDa subfraction of the extract. Washout assays confirmed that the effect was parasitostatic rather than parasiticidal, where the malaria parasites underwent developmental arrest but remained morphologically normal and resumed growth post-removal. Furthermore, priming human endothelial cell lines with the extract significantly reduced IRBC–endothelial binding. These results demonstrate that A. muricata extract exerts a dual-action effect by arresting P. knowlesi asexual replication and inhibiting IRBC–endothelial cytoadherence. While clinical translation would require exhaustive standardization and chemotypic profiling due to the natural variability of plant compositions, these findings provide a foundational academic framework for the potential of A. muricata leaf extract in mitigating severe knowlesi malaria complications.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070183

Authors: Ikhona Ntshobane Dominic Targema Abaver

Background: Opportunistic infections remain a significant cause of morbidity among people living with HIV (PLHIV) in sub-Saharan Africa despite expanded access to antiretroviral therapy (ART). This study evaluated the association between immune status, viral load suppression, ART adherence, and the risk of opportunistic infections among HIV-positive patients receiving ART in the rural Eastern Cape, South Africa. Methods: A retrospective cross-sectional study was conducted using clinical records of HIV-positive patients attending an HIV clinic in Mthatha between January 2021 and December 2024. Demographic characteristics, CD4 counts, viral load results, ART regimens, adherence status, and documented opportunistic infections were extracted. Viral load suppression was defined according to WHO guidelines as <1000 copies/mL. CD4 counts were categorized as <200, 200–499, and ≥500 cells/mm3. Multivariable logistic regression analysis was performed to identify independent predictors of opportunistic infections. Results: A total of 155 patients (105 females, 50 males) were included. Females demonstrated significantly higher mean CD4 counts than males (p = 0.037) and better ART adherence (p < 0.001). Tuberculosis, hepatitis B virus, and herpes simplex virus infections were more prevalent among males, whereas candidiasis was significantly more common among females (p = 0.034). In multivariable analysis, CD4 count < 200 cells/mm3, unsuppressed viral load, and poor ART adherence were independently associated with increased odds of opportunistic infections. Conclusions: Immune suppression and suboptimal ART adherence significantly increase the risk of opportunistic infections among HIV-positive patients in rural South Africa. Strengthening adherence interventions and early immune monitoring may reduce infection burden in high-prevalence settings.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070182

Authors: Maciej Grzybek Anna Bogacka

Climate change is reshaping the epidemiology of vector-borne diseases in Europe by altering the ecological conditions that determine vector survival, seasonal activity and pathogen transmission. Rising temperatures, milder winters, prolonged warm seasons and changing precipitation patterns are increasing the suitability of parts of Europe for competent mosquito, tick and sandfly vectors. These changes, combined with human mobility and land-use change, increase the probability that imported pathogens encounter permissive conditions for local transmission. This Opinion article examines autochthonous vector-borne disease transmission in Europe, using dengue as a sentinel example of a wider climate-sensitive transition. We discuss how imported viraemic cases, established competent vectors, vector–host contact and delayed clinical recognition can converge to enable local outbreaks. Beyond dengue, we consider West Nile virus, chikungunya, tick-borne encephalitis, leishmaniasis and Crimean–Congo haemorrhagic fever as examples of a broader and increasingly heterogeneous European risk landscape. We argue that the public-health impact of this transition is shaped not only by vector expansion, but also by gaps in surveillance integration, diagnostic readiness, workforce preparedness and One Health coordination. Strengthening climate-informed surveillance, rapid laboratory capacity, frontline clinical awareness and cross-sectoral response systems will be essential to prevent repeated introductions from becoming sustained public-health challenges.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070181

Authors: Immamul Muntasir Md. Omar Qayum Arifa Hasnat Ali Fahim Mohammad Sadique Srijon Mohammad Rashedul Hassan Mahbubur Rahman Tahmina Shirin

Early detection of infectious disease outbreaks is critical in densely populated, resource-limited settings. This study aimed to describe the community-based surveillance (CBS) system and its application of the Data–Information–Knowledge–Wisdom (DIKW) framework in Bangladesh. CBS was implemented in 12 urban wards across Dhaka South, Rajshahi, and Sylhet, where trained community volunteers conducted routine household visits to identify five priority syndromes. Data were collected through a mobile application integrated with an automated pipeline for cleaning, geocoding, cluster detection, and alert generation. Between January and June 2025, 38,489 households were visited, enrolling 128,626 individuals. The system generated 10,191 alerts and 577 clusters, predominantly for suspected dengue (58.7%), followed by acute watery diarrhea (24.1%) and influenza-like illness (10.7%). Rajshahi contributed the majority of alerts and clusters. Spatiotemporal analysis identified ward-level outbreak signals, including localized dengue peaks across all three cities. Over 98% of records were synchronized within 24 h, and more than 99% of data entry errors were automatically corrected, ensuring timely and high-quality analytics. These findings demonstrate that digital CBS can effectively transform community-level data into actionable public health intelligence, supporting early outbreak detection and response. This translation enabled timely public health actions, including targeted outbreak investigations and localized vector control measures in identified hotspots. Integration with national surveillance platforms may further strengthen health system responsiveness and epidemic preparedness.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070180

Authors: Messaoud Bouragba Samir Abdellaoui Sarah Saci Nasir A. Ibrahim Mohammed Saad Aleissa Nosiba S. Basher Nesrine Goumich Sundes Rabia Khelifa Meriem Aissou Abir Belakehal Hadjer Djaafer AbdElkarim Laatamna

Cystic echinococcosis (CE), a neglected zoonotic disease caused by Echinococcus granulosus sensu lato, poses a persistent public health burden in agro-pastoral regions worldwide. This study provides a large-scale epidemiological assessment of CE, highlighting sustained zoonotic transmission driven by agro-pastoral practices and human–animal interactions, and supporting the urgent implementation of One Health strategies. This ten-year retrospective study (2015–2024) analyzed 326 surgically confirmed cases from five hospitals in Djelfa. The cumulative surgical incidence was 2.04 cases per 100,000 person-years, classifying the region as hypoendemic. Females predominated (61.96%), and individuals aged 31–60 years represented 47.24% of cases. Rural residence (73.62%) and dog contact (94.17%) were major risk factors, with hepatic localization dominating (88.96%). Correlation analysis showed moderate associations between rural habitat and dog contact (V = 0.46, p < 0.001) and between sex and habitat (V = 0.34, p < 0.001), as well as weaker but significant associations for age and cyst location (V = 0.28, p < 0.001) and dog contact and cyst location (V = 0.20, p < 0.05). No postoperative mortality was recorded. These findings confirm active transmission linked to agro-pastoral practices and emphasize the need for coordinated One Health control strategies.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070179

Authors: Islam Karmokov Olga Freylikhman Regina Baimova Daria Grechishkina Gelena Lunina Ivan Lyzenko Ekaterina Riabiko Tatiana Arbuzova Anastasiia Bachevskaia Edward Ramsay Erik Khalilov Karina Kukleva Lyubov Bespyatova Sergey Bugmyrin Maxim Petrov Olga Neverova Ksenia Titarchuk Vera Agasoi Nikolai Kalinin Olga Vorobyeva Olga Mikheenko Tatiana Iakimenko Inna Druzhinina Olga Matina Daria Monastyrskaya-Nuzhina Anna Smirnova Nikolay Tokarevich

Rickettsia spp. are ubiquitous in nature and capable of causing diseases of varying severity. The most extensive group comprises the spotted fever group (SFG) Rickettsiae, the members of which are predominantly transmitted by ticks. The expansion of tick habitats observed in recent decades poses an increasing threat of dissemination of tick-borne infections into regions previously considered non-endemic. The aim of this study was to determine the prevalence of SFG Rickettsiae in ixodid ticks collected in Northwest Russia and to characterize the species diversity of these pathogens within the study area. Questing adult ixodid ticks (n = 4566) were collected from eight regions of Northwest Russia (Arkhangelsk, Kaliningrad, Leningrad, Novgorod, Pskov and Vologda Regions, as well as the Republic of Karelia and St. Petersburg) in 2023 to 2025 (from April to September). The species composition included Ixodes ricinus (n = 1683), Ixodes persulcatus (n = 2404), and Dermacentor reticulatus (n = 479). Genomic DNA was extracted from individual ticks and screened for SFG Rickettsiae using real-time PCR, followed by conventional PCR targeting the gltA, ompA, ompB, and sca4 (gene D) genes. Nucleotide sequences obtained for a subset of positive samples for the various genes were analyzed. The overall prevalence of SFG Rickettsiae was 12.6% (95% CI: 11.7–13.6). Circulation of the following species was detected: Rickettsia helvetica, Rickettsia conorii subsp. raoultii, Candidatus Rickettsia tarasevichiae, Rickettsia monacensis, and Rickettsia felis. The findings indicate considerable species diversity of SFG Rickettsiae in natural foci of Northwest Russia. Rickettsia monacensis was detected in ixodid ticks within the study area for the first time, and R. felis was identified in Russia for the first time.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070177

Authors: Mehmet Hakan Taskin Sule Ozturk Esra Tas Reyhan Caliskan Ergin Kariptas Ecem Dilara Aygun Seda Gozel Zafer Yazici Ahmed Eisa Elhag

Background: HIV has been a major global health issue since the 1980s. The proportions of diagnosed and undiagnosed infections are important indicators of HIV control. This study investigated the prevalence and characteristics of HIV based on blood samples from patients presenting for diagnosis and treatment at a tertiary healthcare hospital in the Central Black Sea Region over a four-year retrospective period. Methods: We retrospectively evaluated 271,367 samples submitted for anti-HIV serology testing for pre-operative screening or clinical suspicion between 2020 and 2023. HIV-1/2 antibodies and p24 antigen were screened using chemiluminescence microparticle immunoassay (CMIA), and reactive samples were confirmed by real-time RT-PCR. HIV RNA results and immunological parameters were also analyzed. Results: Among 271,367 samples, 694 were HIV-positive, yielding a prevalence of 0.25%. Of 2207 individuals tested for HIV RNA, 699 (31.7%) were positive. HIV RNA positivity was higher in men than women (35.5% vs. 18.6%). Absolute CD4+ T-cell counts were similar between genders, while the CD4/CD8 ratio was significantly higher in women. Both CD4+ T-cell counts and CD4/CD8 ratios increased significantly after three months of treatment. Conclusions: This study demonstrates a low but increasing HIV seroprevalence in the region, with a clear predominance among males and young adults. The findings also reflect effective viral suppression among treated patients and significant immunological recovery after therapy, providing important regional data to guide HIV monitoring and public health interventions.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070178

Authors: Naveed Ahmed Wardah Yusof Nurfadhlina Musa Kueh Yee Cheng Nurzulaikha Abdullah Rosline Hassan Muhammad Nashrul Farhan Samsudin Alwi Muhd Besari Hashim Manickam Ravichandran Chua Wei Chuan Chan Yean Yean

Neutralizing antibodies (NABs) play a critical role in assessing the immune response elicited by vaccines, providing insight into their protective efficacy. Despite their importance, there is a notable gap in research directly comparing NAB levels among individuals vaccinated with different vaccines, across diverse ethnicities, and between genders. The study aimed to compare NAB levels across variables such as vaccination status, vaccine type, age, gender, and ethnicity. The NAB levels among different study groups were measured using the Finecare RBD Antibody Test and the cPass kit (ELISA). The data was analyzed statistically using SPSS version 27. A total of 172 study subjects were analyzed. The mean age of participants was 45.03 ± 16.72 years, with 50.9% male and 77.3% of Malay ethnicity. Median NAB levels, assessed by both assays, were highest in females, vaccinated healthy participants, and those who received the Pfizer vaccine. Age-group comparisons revealed variations in median NAB levels across studied groups. Participants aged 10–25 years in the vaccinated healthy (VH) group exhibited the highest median antibody levels; on the other hand, the 26–45 year age group showed the highest median levels in the breakthrough infection (BI) and certain non-vaccinated categories. Ethnic group comparisons highlighted that Malays consistently had the highest median NAB levels. Significant differences in antibody levels were found across vaccination status, ethnicity, and vaccine type (p < 0.001). This study underscores the influence of vaccination status, demographic factors, and vaccine type on NAB levels. The Finecare RBD Antibody Test and cPass kit demonstrated comparable trends, highlighting their utility in evaluating vaccine-induced immunity. The findings of this study highlight the need for tailored immunization strategies to optimize protective immunity.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070176

Authors: Shewaye Belay Tessema Afework Mulugeta Bezabih Helen P. Price

Cutaneous leishmaniasis (CL) is highly prevalent in northern Ethiopia but data on community knowledge, attitudes, and health-seeking behaviours remain limited. A cross-sectional survey was conducted between November and December 2022 in CL-endemic areas of Tigray using mixed sampling and a structured questionnaire administered to 512 households. Knowledge of CL transmission was poor: only 1% correctly identified sand flies as the vector, while 25% believed the disease was genetically acquired. Approximately 67% of participants perceived CL as stigmatizing, and 63.3% reported a preference for traditional or local treatments over biomedical care. Knowledge levels were higher among rural residents and in households with prior CL experience. Gender and education were significantly associated with treatment-seeking and prevention practices, and participants from households with previous CL episodes reported better practices overall. Despite this, most participants demonstrated limited knowledge, unfavourable attitudes and suboptimal treatment-seeking and prevention behaviours. These findings highlight a disconnect between high disease burden, perceived seriousness and stigma, and limited understanding of transmission and prevention. Targeted, community-based health education interventions are needed to improve awareness of transmission, reduce stigma, and enhance access to effective treatment in CL-endemic settings.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070175

Authors: Mequanente Dagnaw Destaw Fetene Teshome Tilahun Bizuayehu Demass Abebaw Gebyehu Worku

Background: HIV-HBV co-infection remains a major public health challenge, particularly in sub-Saharan Africa. HBV co-infection worsens clinical outcomes among people living with HIV by accelerating liver disease and complicating treatment. Although antiretroviral therapy can effectively suppress both viruses, achieving optimal HIV viral suppression remains critical for reducing morbidity and transmission. While several factors influencing viral suppression among PLHIV are well documented, evidence on HIV viral suppression among HIV-HBV co-infected individuals is limited, especially in resource-limited settings like Ethiopia. Furthermore, data on the magnitude of viral suppression and its associated factors in this population are scarce. Therefore, this study aimed to assess the magnitude of HIV viral suppression and identify its associated factors among adult HIV-HBV co-infected patients in Northwest Ethiopia. Objective: This study aimed to assess the magnitude and factors associated with HIV viral suppression among adult people living with HIV-HBV Co-infection in Northwest Ethiopia. Methods: An institution-based cross-sectional study was conducted in Northwest Ethiopia among adults with HIV-HBV co-infection on antiretroviral therapy. A simple random sample of 402 participants was selected. Data were collected using a pretested structured interviewer-administered questionnaire and medical record review, covering sociodemographic, clinical, behavioral, treatment, follow-up, and adherence factors. HIV viral suppression was defined as a plasma viral load < 1000 copies/mL. Data were coded in EpiData 4.6 and analyzed using STATA 18. Descriptive statistics estimated suppression rates. Bivariable and multivariable logistic regression identified factors associated with suppression; variables with p < 0.25 in bivariable analysis were included in the multivariable model. Statistical significance was set at p < 0.05 with adjusted odds ratios and 95% confidence intervals reported. Model fit was assessed using the Hosmer–Lemeshow test, and multicollinearity was checked using variance inflation factors. Results: There were 423 participants in all. Among the 423 HIV-HBV co-infected adults on antiretroviral therapy included in this study, 138 (34, CI, 30–39%) achieved HIV viral suppression, while 264 (66%) had an unsuppressed viral load at the time of assessment. Viral suppression was found to be independently correlated with the ART TDF-3TC-LPV/r regimen, first-line medication adherence, bedridden functional level, missed clinic appointments, and length of therapy. While TDF-3TC-LPV/r usage (AOR 2.34; 95% CI: 1.40–3.90) and longer treatment duration (AOR 2.09; 95% CI: 1.30–3.34) were advantageous, good adherence significantly improved the likelihood of suppression (AOR 5.54; 95% CI: 3.27–9.38). Missed appointments and a bedridden state decreased the likelihood of suppression. Conclusions: HIV viral suppression was achieved in only 34% of participants. Adherence, ART regimen, treatment duration, functional status, and retention in care were significant predictors. Strengthening adherence support, patient retention, optimized ART regimens, routine viral load monitoring, and targeted care for high-risk patients could improve treatment outcomes and help Ethiopia achieve UNAIDS viral suppression targets.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070174

Authors: Suji Y. O’Connor Mary Lorraine Mationg Matthew J. Kelly Gail M. Williams Archie C. A. Clements Banchob Sripa Somphou Sayasone Virak Khieu Kinley Wangdi Donald E. Stewart Sirikachorn Tangkawattana Apiporn T. Suwannatrai Vanthanom Savathdy Visal Khieu Peter Odermatt Catherine A. Gordon Sangduan Wannachart Donald P. McManus Darren J. Gray

Opisthorchis viverrini (OV) is a liver fluke endemic to the Lower Mekong Basin. Infections often begin in childhood and are causally linked to cholangiocarcinoma, an often-fatal bile duct cancer. Anthelmintic treatment is the primary control strategy, but infection can recur. Therefore, additional strategies are needed. This study assessed the impact of “The Magic Glasses Opisthorchiasis” (MGO), a cartoon-based intervention, on schoolchildren’s OV-related knowledge, attitudes and practices (KAP). A cluster (school)-randomised controlled trial was conducted in Cambodia, Laos and Thailand. Clusters were randomised into either school health education only or with MGO. OV KAP was measured using a standardised questionnaire. FGDs and interviews were also conducted in intervention schools with schoolchildren, parents, and teachers. Cambodia intervention knowledge and attitude scores improved by 19.2 (p < 0.001) and 25.3 (p < 0.001) percentage points, respectively, relative to the control. Laos intervention knowledge and attitude scores improved by 19.0 (p < 0.001) and 14.2 (p < 0.001) percentage points. However, Thailand’s intervention knowledge and attitude scores declined by 23.3 (p < 0.001) and 15.8 percentage points (p < 0.001). There were no improvements in behaviour scores in any country, but parents and schoolchildren in Cambodia and Laos reported improved fish preparation practices, suggesting positive spillover effects from MGO. The findings support MGO as an effective tool for school-based health education.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070173

Authors: Thialao Sarr Mame Thierno Bakhoum Aminata Ba Gorgui Diouf Moussa Fall Mamadou Lamine Djiba Abdou Samath Thiall Modou Moustapha Lo Jessica Radzio Basu Assane Gueye Fall

Rift Valley fever virus (RVFV) and Crimean–Congo hemorrhagic fever virus (CCHFV) are endemic zoonotic pathogens in Senegal, transmitted by mosquitoes and ticks, respectively. Understanding the seasonal and spatial dynamics of their vectors is essential to improve targeted surveillance. This study investigated the abundance, diversity, and viral infection status of vector populations in a transboundary region (Matam) and a non-transboundary region (Thiès) over two seasons from September 2022 to March 2024. We collected mosquitoes using CO2-baited CDC light traps and sampled ticks directly from domestic small ruminants. A total of 6558 mosquitoes across 23 species and 1904 ticks representing seven species were morphologically identified. Mosquito abundance peaked significantly during the rainy season. Conversely, tick diversity increased during the dry season, with Hyalomma rufipes emerging as the predominant species. Crucially, RVFV was detected exclusively in Aedes vexans mosquito pools from the transboundary Matam region, emphasizing the epidemiological risk associated with cross-border livestock mobility. Viral RNA of CCHFV was detected in multiple tick species across both regions and seasons, confirming a sustained, multi-vector enzootic cycle. These findings demonstrate persistent RVFV and CCHFV circulation in Senegal and highlight the critical need for integrated, season-specific vector surveillance frameworks.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070172

Authors: Samiullah Sajjad Parnpen Viriyavejakul Dorn Watthanakulpanich Sant Muangnoicharoen Paron Dekumyoy Wirongrong Chierakul Chayasin Mansaguan Prakaykaew Charunwatthana

Background: Hydatid disease, caused by Echinococcus granulosus, remains a significant public health concern in endemic regions. This study aimed to evaluate the role of ultrasound in the diagnosis, staging, and clinical management of liver hydatid cysts in the eastern city of Jalalabad, Afghanistan. Method: A cross-sectional study was conducted between February and November 2024 among 159 patients diagnosed with liver hydatid cysts. Demographic, clinical, laboratory, and imaging data were collected. Cysts were classified according to the WHO Informal Working Group on Echinococcosis (WHO-IWGE) and Gharbi systems. Ultrasound findings were compared with computed tomography (CT), and their association with treatment decisions was assessed. Result: A total of 159 patients with liver hydatid cysts were included in the study. Among them, 91 (57.2%) were female, 80 (50.3%) were aged 20–39 years, and 128 (80.5%) resided in rural areas. Most patients presented with a single cyst (144/159, 90.6%), while multiple cysts were observed in 15 (9.4%). The majority of cysts measured 5–9.9 cm in diameter (43.4%), followed by 1–4.9 cm (42.1%) and ≥10 cm (14.5%). According to the WHO-IWGE classification, CE1 (25.8%) and CE4 (24.5%) were the most common stages, followed by CE2 (17.6%), CE3a (13.8%), CE3b (11.3%), and CE5 (7.0%). Common exposure-related factors included dog ownership, poor hygiene practices, and consumption of raw vegetables. Ultrasound accurately identified cyst stages and demonstrated a significant association between WHO-IWGE staging and treatment modality (χ2 = 63.56, p < 0.001). Almost perfect agreement was observed between ultrasound and CT for cyst classification (Cohen’s κ > 0.90), although CT provided additional anatomical information in selected complex cases. Conclusions: Ultrasound is an accessible, accurate, and reliable imaging modality for the diagnosis, staging, and management of liver hydatid cysts. In resource-limited settings, it serves as the primary imaging modality for guiding clinical decision-making, with CT reserved for complex or uncertain cases.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11070171

Authors: Indira Karibayeva Gulzar Shah Nikolay Lunchenkov Roza Kuanyshbekova Kuanysh Shonbay Botagoz Turdaliyeva

Background: HIV/AIDS remains a major global public health challenge, with persistent regional disparities in burden and progress toward the UNAIDS 95–95–95 targets. This study assessed temporal trends in the HIV/AIDS burden in Kazakhstan, compared them with Central Asia and global patterns, and projected trends through 2030. Methods: We conducted a population-level analysis using Global Burden of Disease 2023 data, examining age-standardized rates (per 100,000) of incidence, prevalence, mortality, disability-adjusted life years (DALYs), years of life lost (YLLs), and years lived with disability (YLDs) from 2010 to 2023. Trends were quantified using percent change and average annual percentage change, with projections based on log-linear models. Results: Between 2010 and 2023, prevalence in Kazakhstan increased by 332.1% and incidence by 111.0%, contrasting with the decline in global incidence (−24.7%). Mortality decreased (−32.7%), along with DALYs (−28.8%) and YLLs (−37.1%), while YLDs increased by 135.5%, indicating a shift toward a chronic disease burden. In 2023, Kazakhstan had a lower overall burden than global estimates but showed steeper increases in incidence and prevalence. Age-specific analyses indicated the largest increases among adults aged 30–69 years. Under current trend assumptions, projections suggest continued growth in prevalence and incidence, with modest mortality declines through 2030, though these trajectories do not account for future changes in prevention coverage, treatment access, or policy. Conclusions: Kazakhstan is undergoing a transition toward a chronic HIV epidemic, underscoring the need to strengthen prevention, expand PrEP and testing coverage, and address structural barriers to achieve epidemic control.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060170

Authors: Solomon Monday Jacob Sophie Y. Akinbo Oluwaremilekun G. Ajakaye Uwem F. Ekpo Zainab Omoruyi Temitope Agbana Louise Makau-Barasa Moses O. Aderogba Jan-Carel Diehl David Bell Adedotun A. Bayegun Michael A. Okungbowa Juliana A-Enegela Frederick O. Akinbo

Schistosomiasis remains a major public health concern in Nigeria. We molecularly characterized Schistosoma eggs obtained from human urine to identify species and assess the presence of hybrid schistosomes in Abuja, Nigeria. Urine samples were collected from 1887 participants aged five years and above. Samples were examined for Schistosoma eggs using light microscopy. A total of 507 (26.9%) were positive for any form of Schistosoma while 91 (4.8%) had atypical Schistosoma eggs. DNA extracted from pooled ova was analyzed using metagenomic sequencing, read mapping, phylogenetic analysis, and BLASTn confirmation. Molecular analyses identified genetic signatures associated with both S. haematobium and S. bovis within pooled human urine samples, indicating the co-circulation of multiple schistosome species in the study area. Phylogenetic analyses based on trans-ITS and mitochondrial COX1 markers supported the presence of distinct nuclear and mitochondrial schistosome lineages. However, because sequencing was performed on pooled egg samples, the findings cannot distinguish between true recombinants and mixed infections involving co-circulating parental species. These findings highlight the potential complexity of schistosome transmission dynamics in endemic communities and underscore the need for enhanced molecular surveillance, especially single-parasite genomic approaches, and integrated One Health investigations to better understand schistosome transmission and its implications for control and elimination efforts in Nigeria.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060169

Authors: Thomas Fotas Ioannis A. Giantsis Menelaos Lefkaditis Ioannis S. Pappas Mathis A. B. Christodoulopoulos Efterpi Zafiriou Electra Nicolaidou Alexander C. Katoulis Georgios Christodoulopoulos

Tungiasis is a cutaneous ectoparasitosis caused by the penetration of gravid female Tunga penetrans fleas into the epidermis. Although endemic in tropical and subtropical regions, it remains rare in Europe, where most cases are travel-associated and secondary household transmission is seldom documented. This study describes imported tungiasis in Greece and investigates possible secondary household transmission in a non-endemic setting. Seven Greek men residing in Attica developed tungiasis following occupational exposure in Tanzania, together with one secondary case in a non-travelling household contact who had never travelled outside Greece. Diagnosis was based on clinical and dermoscopic findings and confirmed by amplification and sequencing of the mitochondrial cytochrome oxidase I (COI) gene. Household investigations were also performed. Eight male patients presented with painful plantar and/or subungual nodular lesions. Sequence analysis of COI demonstrated 657/662 bp (99%) identity with the Tunga penetrans reference sequence, and identical sequences were identified in all samples. A representative sequence was deposited in GenBank (accession no. PZ336383). All patients exhibited mild-to-moderate elevations of hepatocellular and cholestatic liver enzymes, which resolved within two weeks following treatment. One probable secondary household case was identified, and no infestation was detected among additional cohabitants or companion animals. This report documents imported tungiasis with probable secondary household transmission in Greece and highlights the importance of clinical awareness and environmental assessment in non-endemic settings.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060168

Authors: R Lia Kusumawati Mirzan Hasibuan Nisrina Tari Gema Nazri Yanni Laura Isa Ginting Cynthia Gozali Tryna Tania

(1) Background: Indonesia faces the dual challenge of a high tuberculosis (TB) burden and increasing drug resistance. Conventional molecular diagnostics frequently fail to detect isoniazid resistance and nontuberculous mycobacteria (NTM). This study evaluates a domestic multiplex Open PCR system in Medan, Indonesia. (2) Methods: From July to November 2025, 1569 sputum specimens from suspected TB patients were analysed using the Indigen MTB/NTM/DR-TB Real-time PCR Kit Gen 2. (3) Results: Mycobacterial DNA was detected in 421 specimens (26.8%). Among these, 396 (94.1%) were drug-susceptible TB, while 16 (3.8%) showed resistance, predominantly INH mono-resistance (n = 14; 0.89% of total). Additionally, 9 cases (2.1%) involved NTM or TB-NTM co-infections. Tertiary hospitals showed significantly higher positivity rates (33.5%) than primary care (18.9%; p < 0.001). TB status was significantly associated with male (p = 0.0052) and older age (p = 0.006), whereas resistance profiles and NTM distribution were consistent across all demographic groups (p > 0.80). (4) Conclusions: This study describes the implementation and diagnostic yield of a domestic multiplex Open PCR system in Medan, Indonesia. By bridging diagnostic gaps across a decentralized referral network, this facilitates rapid and targeted therapy. Integrating multiplex domestic innovations into national diagnostic algorithms is essential for achieving Indonesia’s TB elimination targets.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060167

Authors: Andrea Ciammaruconi Anna Rocchetti Filippo Molinari Elisa Recchia Nathalie Totaro Chiara Pascolini Silvia Chimienti Giovanni Faggioni Riccardo De Santis Filippo Moramarco Alberto Autore Florigio Lista

Dengue virus infection remains a significant public health challenge in endemic regions, with growing evidence of autochthonous transmission in Europe. Assessing serological exposure in high-risk populations such as military personnel deployed to endemic areas is essential to quantify exposure risk and support operational decision-making, particularly regarding pre-deployment counselling and risks associated with secondary infection. We conducted a cross-sectional study involving 1355 members of the Italian Armed Forces, measuring anti-dengue IgG antibodies by ELISA and collecting data on deployment history and exposure risk. Overall, IgG seropositivity was 8.12%, with significantly higher prevalence among individuals reporting travel or deployment to endemic regions (24.71%) compared with non-exposed personnel (4.27%). Seropositivity increased with age and correlated with a CDC-derived cumulative dengue risk score (Spearman’s ρ = 0.299, p < 0.0001). A multivariable logistic regression model including age and exposure risk achieved an AUC of 0.75, while machine-learning models provided complementary predictive assessment, with random forest reaching an AUC of 0.79. These findings indicate substantial anti-dengue IgG seropositivity compatible with previous dengue exposure among Italian military personnel, particularly those deployed to endemic settings. The study highlights the need for targeted surveillance and risk-based preventive strategies, and supports the use of exposure-based models to improve epidemiological assessment and inform vaccination strategies in mobile populations.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060166

Authors: Ivan Lyzenko Olga Stukolova Nikolay Tokarevich Marina Sokolova Regina Baimova Islam Karmokov Ekaterina Riabiko Daria Grechishkina Gelena Lunina Vladimir Dedkov

Background: Borrelia miyamotoi is an emerging tick-borne pathogen causing relapsing fever in humans. Although Saint Petersburg and the surrounding Leningrad Oblast harbor a high abundance of ixodid ticks (I. ricinus, I. persulcatus), no integrated assessment has yet simultaneously addressed pathogen circulation in vectors, reservoir hosts, and human populations in this specific northwestern region of Russia. Methods: During 2022–2024, we collected 1518 questing adult ticks and trapped 516 small mammals in Saint Petersburg and Leningrad Oblast. B. miyamotoi DNA was detected by real-time PCR. Sera from 3743 randomly selected volunteers (1553 from Saint Petersburg, 2190 from Leningrad Oblast) were tested for anti-B. miyamotoi IgG/IgM using a protein microarray (antigens: GlpQ, Vmps, flagellin). Infection rates and seroprevalence with 95% Wilson confidence intervals were compared using chi-square tests. Results: The overall tick infection rate was 3.78% (57/1506). I. ricinus had a significantly higher prevalence (4.94%; 95% CI: 3.67–6.60%) than I. persulcatus (2.29%; 95% CI: 1.39–3.74%; p = 0.011). Ticks from Leningrad Oblast also showed markedly elevated infection rates (4.98%; 95% CI: 3.75–6.58%) compared to those from Saint Petersburg (1.89%; 95% CI: 1.06–3.35%; p = 0.004). Small mammals exhibited substantially higher infection rates in Leningrad Oblast (39.44%; 95% CI: 31.78–47.65%) than in Saint Petersburg (13.90%; 95% CI: 10.76–17.78%; p < 0.001). Bank voles (Myodes glareolus) and yellow-necked mice (Apodemus flavicollis) were the main reservoirs; synanthropic rodents trapped within the city were found to be infected for the first time. No significant organotropism was detected, but positive correlations between infection in the heart, liver, and kidney suggested hematogenous dissemination. The overall human seroprevalence of B. miyamotoi was 1.71% (95% CI: 1.34–2.18%) and was significantly higher in Leningrad Oblast (2.19%; 95% CI: 1.66–2.89%) than in Saint Petersburg (1.03%; 95% CI: 0.64–1.67%; p = 0.010). In contrast, the seroprevalence of B. burgdorferi s. l. did not differ between the two regions (approximately 5.1%). Conclusions: This first comprehensive, multi-level investigation in Saint Petersburg and Leningrad Oblast reveals a stable epidemiological gradient: natural foci in Leningrad Oblast sustain higher B. miyamotoi circulation in ticks and rodents, which translates into a two-fold higher exposure of the rural population. The findings highlight the need to include B. miyamotoi in regional tick-borne infection surveillance programs and to adopt differentiated risk assessment strategies for urban and rural settings.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060165

Authors: Sumon Ghosh Mohammad Nayeem Hasan Sukanta Chowdhury Narayan C. Paul Waqas Ahmad Jiangang Chen Thankam S. Sunil

Rabies remains a preventable yet fatal zoonotic disease and a major public health concern in Bangladesh, which aims to eliminate dog-mediated human rabies by 2030. Despite free availability of post-exposure prophylaxis (PEP), adherence to the WHO-recommended PEP regimen remains low. This study assessed PEP compliance and identified determinants of regimen completion among animal-exposed patients. We conducted a hospital-based observational study using secondary data from 457 patients who initiated PEP at the National Rabies Prevention and Control Centre (NRPCC) in Dhaka, from February 2023 to July 2023. Sociodemographic, clinical, and exposure-related factors were analyzed to identify predictors of compliance. Only 17.1% of patients completed the full PEP regimen, including rabies immunoglobulin (RIG) administration for WHO Category III exposures where indicated. Higher adherence was observed among females, individuals aged ≥15 years, lower-income groups, and those residing within 10 km of the treatment center. Exposure-related factors including dog bites, multiple exposures, unprovoked incidents, and appropriate exposure care were also associated with improved compliance. Despite free access, PEP completion remains critically low. Targeted strategies, including decentralized PEP delivery, improved public awareness, and strengthened follow-up systems, are essential to improve adherence and support progress toward rabies elimination by 2030.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060164

Authors: Carlos Ramiro Silva-Ramos Peter C. Melby Patricia V. Aguilar Miguel M. Cabada Juan David Rodas Marylin Hidalgo Álvaro A. Faccini-Martínez

Spotted fever group (SFG) rickettsioses are emerging zoonotic diseases of increasing relevance in Latin America, yet the specific species involved in human infections remain poorly defined in many endemic regions. This study aimed to determine the most probable antigen among SFG-seroreactive febrile patients from Villeta, Colombia. A panel of 25 convalescent-phase serum samples previously identified as positive for SFG Rickettsia spp. antibodies was analyzed by indirect immunofluorescence assay using antigens of Rickettsia rickettsii, R. amblyommatis and R. parkeri. Antibody titers were compared to identify differential seroreactivity patterns. Overall, 44% (11/25) of the samples showed differential antibody titers against one of the tested antigens. Among these, nine (36%) exhibited higher titers to R. parkeri and two (8%) to R. amblyommatis, while none showed exclusive reactivity to R. rickettsii. The remaining 56% (14/25) presented similar titers across antigens, consistent with indeterminate or cross-reactive SFG responses. Antibody titers ranged from 1:128 to 1:4096, with R. parkeri showing the strongest reactivity. These findings suggest R. parkeri or a highly related Rickettsia species as the predominant probable antigen in Villeta, highlighting its potential role in mild rickettsial infections and emphasizing the need for eco-epidemiological studies to identify local vectors and reservoirs.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060163

Authors: Basílio Felizardo Lima Neto Ana Caroline Dantas Amorim Maria Jessianny Diniz Alves Ana Maria Santos Lima Janielton Albuquerque Lima Celine Sousa Menezes Sá Emilly Henrique Silva João Luís Garcia Vinicius Longo Ribeiro Vilela Thais Ferreira Feitosa

This study aimed to determine the prevalence and risk factors associated with Toxoplasma gondii infection in blood donors from the Brazilian Semiarid region, and to explore its implications for transfusion safety. Samples were collected from 646 donors at blood donation centers in the states of Ceará and Paraíba. Serological diagnosis was performed using BIOLISA TOXOPLASMOSE ELISA kits for anti-T. gondii IgM and IgG antibodies, and molecular diagnosis was conducted by conventional PCR targeting a 529-bp noncoding repetitive fragment. Epidemiological questionnaires on variables associated with infection were administered, and statistical analysis was performed in univariate and multivariate stages, using multiple logistic regression. Among the 646 donors, 43.4% (281/646) were positive for anti-T. gondii IgG antibodies, 0.3% (2/646) for IgM antibodies, and none tested positive by PCR. In the univariate analysis, age, family income, educational level, salad washing practices, water source, raw milk consumption, and duration as a donor were significantly associated, whereas in the multivariate analysis only “age” and “salad washing practices” remained significant. A substantial IgG seroprevalence was observed among blood donors in the Brazilian Semiarid. The low IgM frequency, concurrent IgG positivity, and negative PCR results are consistent with a low transfusion risk in the region. However, these findings should be interpreted cautiously, as negative PCR results do not completely rule out the presence of circulating parasites. Age was identified as a risk factor, whereas proper salad washing showed a protective effect.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060162

Authors: Paula A. Avilés-Vergara Dina Ricardo-Caldera Carlos Alberto Bolívar Pineda Eliud Daniel Pérez Vergara Ana Carolina Negrette Oquendo Luis Carlos Ruiz Garces Sara Cecilia Soto-De León Catalina Tovar-Acero

Background/Objectives: Arboviral diseases transmitted by Aedes mosquitoes, including Dengue (DENV), Zika (ZIKV), and Chikungunya (CHIKV), represent a major public health challenge in tropical regions. Their clinical similarity complicates differential diagnosis, particularly in settings of viral co-circulation, and may lead to underdiagnosis. The objective was to detect acute dengue infection and assess serological evidence of Chikungunya and Zika virus exposure among patients with acute febrile syndrome and clinical suspicion of dengue in the department of Córdoba, Colombia. Methods: A prospective descriptive study was conducted between 2023 and 2024 in healthcare institutions in Montería and Sahagún. Serum samples were analyzed by ELISA to detect DENV NS1 antigen, anti-CHIKV IgM, and anti-ZIKV IgG antibodies. Sociodemographic, clinical, and laboratory variables were described, and the association between prior ZIKV infection and dengue severity was assessed. Results: Ninety patients were included. Isolated laboratory marker detection was observed for DENV NS1 antigen in 36.7% (33/90), anti-ZIKV IgG in 30.0% (27/90), and anti-CHIKV IgM in 2.2% (2/90); combined arboviral markers were identified in 22.2% (20/90), and 8.9% (8/90) had no detectable markers. Among NS1-confirmed dengue cases (n = 47), 61.7% (29/47) were classified as dengue with warning signs. Anti-ZIKV IgG detection was not associated with dengue clinical classification (p = 0.989), although platelet counts were lower in IgG-positive cases (p = 0.037). Conclusions: The findings support laboratory-supported diagnosis and integrated acute febrile illness surveillance in Córdoba, including locally adapted vector control, in a setting of arbovirus co-circulation with overlapping laboratory markers.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060161

Authors: Elichilia Robert Shao Jeremia J. Pyuza Tito Kibona Laura Shirima Eliaichi A. Mlay Alice Andongolile Ray Kayaga Semvua Kilonzo Blandina T. Mmbaga Jaffu Chilongola

Background: Crimean–Congo hemorrhagic fever virus (CCHFV) is an important tick-borne zoonosis and an emerging public health threat across Africa. Although evidence of viral circulation is mounting, information remains fragmented, limiting a comprehensive understanding of transmission ecology, regional hotspot heterogeneity, and preparedness needs across the continent. Methods: This narrative review critically synthesized published literature on CCHFV in Africa, identified through PubMed, Scopus, and Google Scholar and supplemented by citation tracking and authoritative public health reports. Evidence from epidemiological, ecological, molecular, surveillance, and One Health studies was integrated to examine transmission dynamics, geographic hotspot distribution, viral diversity, risk factors, diagnostic and surveillance challenges, and preparedness strategies. Results: Available evidence shows marked geographic heterogeneity in CCHFV transmission across Africa, with hotspot regions shaped by ecological suitability, Hyalomma tick distribution, livestock–human interactions, and health system capacity. Livestock consistently show higher exposure than humans, underscoring their role as key indicators of viral circulation. Diagnostic limitations, passive surveillance, ecological variability, and serological cross-reactivity contribute to substantial under recognition of disease burden, while molecular studies reveal considerable viral diversity and ongoing evolution across African regions. Conclusions: CCHFV remains underdiagnosed and underreported in many African settings because of limited surveillance and diagnostic capacity. Strengthening integrated One Health surveillance, expanding laboratory and genomic capacity, utilizing livestock as sentinel populations, and improving cross-sectoral collaboration are critical for enhancing early detection, outbreak preparedness, and effective public health response across the continent.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060160

Authors: Tukisho Mphahlele Thendo Gertie Makhado Lufuno Makhado

Background/Objectives: Rifampicin-resistant tuberculosis (RR-TB) and HIV co-infection remain major contributors to morbidity and mortality, particularly in high-burden settings. HIV-related clinical factors, including viral suppression, CD4-defined immune status, HIV drug resistance, virological failure, and ART failure, may influence RR-TB treatment response; however, existing evidence remains fragmented. This systematic review and meta-analysis protocol aims to synthesize evidence on the impact of HIV viral suppression, immune status, and HIV drug resistance/ART resistance status on RR-TB treatment outcomes. Methods: This protocol was developed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols guidelines. Published peer-reviewed studies and relevant grey literature from January 2005 to December 2025 will be searched in PubMed/MEDLINE, Cochrane Library, Embase, Web of Science, ScienceDirect, EBSCOhost, PsycINFO, Google Scholar, and other relevant sources. No language restriction will be applied at the search stage. Where feasible, non-English records will be translated for title/abstract and full-text screening. Two reviewers will independently screen studies, extract data, and assess study quality, with disagreements resolved by a third reviewer. Study-level risk of bias will be assessed using design-appropriate tools, and the certainty of evidence for each outcome will be evaluated using GRADE. Results: Evidence will be synthesized narratively and, where studies are sufficiently homogeneous, quantitatively through meta-analysis. Outcomes of interest will include treatment success, treatment failure, mortality, treatment completion, microbiological cure, and adverse events. Subgroup analyses will be considered by viral suppression status, CD4-defined immune status, HIV drug resistance/ART resistance status, geographic region, and treatment regimen where data permit. Conclusions: This review will provide evidence on how HIV viral suppression, immune status, and HIV drug resistance/ART resistance influence RR-TB treatment outcomes. The findings may inform integrated TB/HIV care, clinical monitoring, and treatment strategies for individuals co-infected with HIV and RR-TB.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060159

Authors: Min Kramyoo Sidhartha Chaudhury Watcharee Yokanit Kamonwan Siriwattanakul Porruthai Kittikanara Brian A. Vesely Darunee Utennam Nakarin Sansanayudh Sutchana Tabprasit

Peacekeeping operations in sub-Saharan Africa continue to be impacted by malaria both in-country and among returning service members. The Royal Thai Army (RTA) deploys an engineering company to Juba and Rumbek, South Sudan to conduct peacekeeping operations as part of the UN Mission in South Sudan (UNMISS). Each deployment is approximately 12 months long. The unit is given doxycycline one week before travel before switching to the UN-provided mefloquine during deployment and for four weeks after returning. The RTA routinely conducts post-deployment screening for malaria by microscopy and PCR for units returning from UNMISS. High rates of prophylaxis failure were observed from both during-mission and post-deployment screening cases, with cumulative malaria attack rates of 11.4% (31 cases out of 271 personnel), 18.2% (49 cases out of 270 personnel), and 23.1% (63 cases out of 273 personnel) for 2023, 2024, and 2025, respectively, with 98% of cases being due to P. falciparum. Furthermore, post-deployment screening revealed high rates of sub-microscopic and sub-clinical parasitemia with 40% of all malaria cases being identified as asymptomatic during post-deployment screening, and 61% of those asymptomatic cases being detected by PCR only. While factors underlying the high prophylaxis failure rate, as well as the high rate of sub-microscopic and sub-clinical parasitemia are unclear, these findings highlight the limitations of relying on clinical symptoms or microscopy for detecting malaria in military units returning from endemic regions and underscore the importance of unit-wide post-deployment molecular screening.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060158

Authors: Huan Xu Sheng Huang Haotian Huang Xinrui Gao Chunlin Chen Guangyu Liang Aili Lu Xuwen Xu Yuyuan Xu Hao Wang Xin Tao Shaohang Cai

People living with HIV (PLWH) represent a high-risk population for hepatitis A virus (HAV) infection, with exposure risk equal to or higher than that of the general population, particularly within adult risk networks. Anti-HAV immunoglobulin G (IgG) serves as a neutralizing antibody and is considered a key marker of protective immunity against HAV infection. However, the serologic profile of anti-HAV IgG and IgM among unvaccinated PLWH remains insufficiently characterized, especially in South China. A total of 1232 unvaccinated adults were enrolled in the study, including 800 PLWH and 432 HIV- negative controls, to evaluate the serological markers of HAV immunity. Serum anti-HAV IgG and immunoglobulin M (IgM) were measured using enzyme-linked immunosorbent assays, and demographic, immunological, and biochemical data were collected. We observed that PLWH had significantly lower anti-HAV IgG concentrations (0.27 ± 0.16 vs. 0.31 ± 0.14 ng/mL, p < 0.001) and a lower IgG seropositivity rate (22.5% vs. 35.6%, p < 0.001) compared with HIV-negative controls, whereas no differences were found in IgM levels or positivity between the two groups. Multivariable logistic regression identified HIV infection (OR = 0.599, 95% CI 0.413–0.869, p = 0.007) and age (OR = 1.019, 95% CI 1.007–1.031, p = 0.002) as independent factors associated with IgG seropositivity. Among PLWH, those who were IgG-positive tended to be older (p = 0.003) and had higher serum globulin levels (p < 0.001), whereas IgM positivity was linked to younger age (p < 0.001) and a higher CD4/CD8 ratio (p = 0.030). Age-stratified analyses further revealed that IgG seroprevalence increased with age, while IgM positivity showed a declining trend. These findings indicate a considerable immunity gap in a population at elevated risk of HAV infection and support the need for targeted serologic screening and vaccination strategies among PLWH.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060157

Authors: Hong-Mei Li Zhi-Qiang Qin Shan Lv Jing Xu Nicholas Midzi Masceline Jenipher Mutsaka-Makuvaza Ting Feng Robert Bergquist Xiao-Nong Zhou

Schistosomiasis is an important snail-borne neglected tropical disease, and detecting infected snails is a priority for its control and elimination. However, conventional parasitological methods, such as crushed snails and cercarial shedding, have limited sensitivity. In this study, we developed a novel loop-mediated isothermal amplification (LAMP) assay (smND1-LAMP) targeting the mitochondrial NADH dehydrogenase subunit 1 (ND1) gene of Schistosoma mansoni. The assay was optimized at 65 °C for 1 h and demonstrated a detection limit of one copy of the pUC57/smND1 recombinant plasmid. Its diagnostic performance was evaluated using laboratory-infected Biomphalaria snails and field-collected samples from Zimbabwe and Burkina Faso, and compared with microscopy, conventional PCR and SYBR Green real-time PCR (SGPCR). In laboratory experiments, smND1-LAMP achieved 100% specificity and 75% sensitivity, outperforming microscopy and showing a similar performance to SGPCR. In field surveys, smND1-LAMP detected a higher positive rate (25.9%) than conventional PCR (22.2%) in Burkina Faso, while microscopy failed to identify any positive snails. Both molecular methods identified infections that were missed by parasitological techniques. These findings demonstrate that smND1-LAMP assay is a sensitive, specific, and field-applicable tool for detecting S. mansoni infection in snails. It provides an effective alternative for routine surveillance and early warning of changing schistosomiasis endemicity.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060156

Authors: Anel Ibrayeva Zhamilya Nugmanova Anarkhan Nurkerimova Aigerim Alimbekova Marat Tukeyev Alfiya Denebaeva Jack DeHovitz Yerlan Ismoldayev Bolat Sadykov Shynar Tanabayeva Ildar Fakhradiyev

Background: Virological suppression is a key outcome of antiretroviral therapy. Despite progress in HIV treatment in Kazakhstan, virological non-suppression remains a relevant clinical and public health issue requiring further analysis. This study aimed to assess the prevalence of virological suppression (VS) and to identify factors associated with the absence of VS among people living with human immunodeficiency virus (HIV) who are receiving antiretroviral therapy (ART) in Kazakhstan. Methods: A retrospective cross-sectional analytical study was conducted using secondary analysis of a de-identified national registry database of people living with HIV (PLHIV) receiving ART in the Republic of Kazakhstan as of 30 September 2025. The primary outcome was virological non-suppression (VNS), defined as the last viral load (VL) value of at least 200 copies per milliliter. The analysis included sex, age, presumed route of HIV transmission, the first available cluster of differentiation 4 (CD4) cell count recorded in the registry, the last recorded percentage category of adherence to ART, and the aggregated category of ART regimen. The main descriptive, bivariate, and multivariable analyses were performed using a complete-case approach. Independent associations were assessed using multivariable logistic regression, and the results were presented as adjusted odds ratios (aORs) with 95 percent confidence intervals (CIs). Results: The initial registry extraction included 33,614 records, of which 32,130 patients were included in the final analytical sample. VS was achieved in 29,454 (91.7%) patients, whereas VNS was observed in 2676 (8.3%) patients. In the multivariable model, higher adjusted odds of VNS were observed among men compared with women (aOR 1.14; 95% CI 1.02–1.26), as well as among patients with a first CD4 count < 200 cells/μL compared with those with a first CD4 count of ≥500 cells/μL (aOR 1.25; 95% CI 1.09–1.44). The strongest association was found for reduced adherence to therapy. Compared with adherence of at least 95%, the adjusted odds of VNS were markedly higher among patients with adherence of 85–94% (aOR 28.66; 95% CI 25.85–31.77) and among those with adherence below 85% (aOR 61.05; 95% CI 50.50–73.81). In all age groups older than 25 years, the adjusted odds of VNS were lower than among patients younger than 25 years. Lower adjusted odds of VNS were also observed among patients with homosexual transmission, vertical transmission, and other or unspecified transmission routes compared with heterosexual transmission. Among ART regimens, regimens containing non-nucleoside reverse transcriptase inhibitors (NNRTIs) were associated with lower adjusted odds of VNS than dolutegravir-containing regimens (DTG-containing regimens) (aOR 0.68; 95% CI 0.52–0.88), whereas no statistically significant differences were identified for regimens containing protease inhibitors (PIs). Conclusions: Despite the high overall level of VS among PLHIV receiving ART in Kazakhstan, VNS remains concentrated in clinically and programmatically important subgroups. It was most strongly associated with reduced adherence and was also associated with younger age, marked baseline immunosuppression, and male sex in the primary model. These findings support the need for targeted interventions focused on adherence support, early diagnosis, and differentiated long-term follow-up of patients.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060155

Authors: Verónica Salomé Sánchez-Peralta Katherine Lizeth Moposa-Balarezo Fabio Marcelo Idrovo-Espín Rommy Terán

Cutaneous Larva Migrans (CLM) is a neglected tropical disease (NTD) caused by zoonotic Ancylostomatidae larvae, mainly Ancylostoma braziliense and Ancylostoma caninum, which infect dogs and cats. Humans are accidental hosts, acquiring infection when L3 larvae in contaminated soil penetrate the skin, producing serpiginous, pruritic lesions. We report a 24-year-old female from Quito, Ecuador, who developed a pruritic lesion on her right foot nine days after walking barefoot on wet, potentially fecally contaminated sand at Atacames Beach. Initial self-treatment with benzyl benzoate and herbal washes, followed by misdiagnoses as scabies and plantar warts, delayed proper care. Lesions progressed over three weeks with intense pruritus and functional impairment. CLM was correctly diagnosed by a podiatric technician 26 days post-exposure. Oral albendazole (400 mg/day for 4 days) led to rapid symptomatic relief within three days, with complete resolution by day 50. A survey analyzed by the McNemar Test revealed difficulties in recognizing early-stage CLM, regardless of experience or region among participants. Prevention requires personal protection, environmental sanitation, and regular anthelmintic treatment of dogs and cats. This case underscores the clinical consequences of delayed or incorrect diagnosis and highlights the need for enhanced healthcare training and One Health measures to reduce zoonotic diseases in Ecuador.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060154

Authors: Charlotte Sriruttan-Nel Bhavani Moodley John Frean Dumisani Mlotshwa Veerle Msimang

Schistosomiasis remains the second leading cause of death among parasitic diseases globally, contributing substantially to chronic morbidity and disability. South Africa (SA) is endemic for schistosomiasis, with ongoing efforts to expand mass drug administration. In the absence of true prevalence data, this study retrospectively analysed public sector laboratory-confirmed schistosomiasis cases from 2019 to 2024. Over this period, 73,680 cases were microscopically diagnosed, with Schistosoma haematobium accounting for 99.9% of infections. The test positivity rate of 20 per 100,000 population is lower than previously reported, with the burden concentrated among boys aged 5–19 years, particularly in the KwaZulu-Natal, Limpopo, and Mpumalanga provinces. These findings highlight a persistent burden within defined demographic groups and geographic areas, while also suggesting possible early signs of improvement that are potentially linked to public health interventions. The results provide valuable evidence to inform the scale-up of national schistosomiasis control programmes and the prioritisation of interventions towards the most affected populations.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060153

Authors: Rithu Chandran Thomas Denagamage Daniel M. Czyz Subhashinie Kariyawasam Abraham Joseph Pellissery

Antimicrobial resistance (AMR) is one of the most serious threats to global public health, driven in part by extensive antibiotic use in food-producing animals. The poultry industry, a major contributor to the global animal protein supply, has depended on antibiotics for growth promotion and disease control, thereby contributing to the emergence and dissemination of AMR zoonotic bacteria. This review synthesizes current evidence on the potential of phytochemicals (PCs), plant-derived bioactive compounds, as sustainable non-antibiotic alternatives for controlling bacterial foodborne pathogens in poultry. Relevant literature including in vitro and in vivo studies assessing PCs against major poultry-associated zoonotic bacteria, including Salmonella enterica, Campylobacter spp., Clostridium perfringens, Listeria monocytogenes, and pathogenic Escherichia coli, is examined. Evidence indicates that PCs exert antimicrobial and anti-virulence effects through mechanisms like bacterial membrane disruption, inhibition of quorum sensing and virulence gene expression, modulation of gut microbiota, and enhancement of host immune responses. In vivo studies demonstrate reductions in pathogen colonization and improvements in gut health and performance metrics in poultry. Despite these promising findings, challenges remain in bioavailability, dose optimization, standardization, and regulatory approval. Overall, PCs represent a promising component of integrated antimicrobial stewardship strategies in poultry production, with significant implications for mitigating zoonotic AMR transmission.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060152

Authors: Esma Kepenek Kurt Rukiyye Bulut Bahar Kandemir İbrahim Erayman

Mucormycosis is a rare, invasive fungal infection associated with high mortality. This retrospective study evaluated adult mucormycosis cases followed in our clinic between 2015 and 2025. A total of 13 patients were included, with a mean age of 50.92 ± 20.65 years (range, 20–83), and 10 (76.9%) were male. The most frequent symptom was facial pain (100%). Four (30.8%) of the patients had rhino-sinusitis, and three (23%) had rhino-orbito-cerebral involvement. Seven (53.9%) of the patients had hematological malignancy, three (23%) had diabetes mellitus (DM), two (15.4%) had a history of COVID-19 pneumonia, and one (7.7%) had a history of both DM and COVID-19 pneumonia. All had elevated C-reactive protein levels. Rhizopus spp. grew in nasal/tissue cultures of three (23%) patients, and so did Mucor spp. Surgery was performed in 11 (84.6%) patients, and fungal hyphae were observed in tissue histopathology. All patients showed radiological findings of mucormycosis on imaging. All patients received Liposomal Amphotericin B, and nine (69.2%) patients received sequential posaconazole therapy. Recurrence occurred in two (15.4%) patients. A total of eight (61.5%) patients, including three (23%) patients with intracranial involvement, died. Mucormycosis is a severe infection, especially in patients with hematological malignancies or DM, despite early diagnosis and combined antifungal and surgical treatments.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060151

Authors: Mario J. Olivera

Malaria reduction in the Americas has slowed despite sustained elimination efforts, suggesting important changes in the spatial organization of residual transmission. This study evaluated whether declining Plasmodium falciparum incidence between 2000 and 2023 was associated with increasing geographic concentration, spatial clustering, and territorial persistence across the region, with detailed subnational analysis in Colombia. Temporal trends were assessed using segmented regression, geographic concentration using Gini and Herfindahl–Hirschman indices, and spatial dependence using Moran’s I and local indicators of spatial association. A Municipal Persistence Index (MPI) was developed to identify municipalities characterized by recurrent high transmission over time. Regional incidence declined by 62.7% but showed progressive temporal deceleration, while more than 80% of cumulative burden remained concentrated in four countries. Since 2020, Colombia has contributed nearly 40% of all reported P. falciparum cases in the Americas. Within Colombia, high-persistence municipalities largely overlapped with statistically significant spatial clusters concentrated along the Pacific region. These findings suggest that residual P. falciparum transmission is increasingly organized into territorially structured persistence systems rather than diffuse endemicity. Advancing malaria elimination may therefore require territorially coordinated One Health strategies aligned with the spatial organization of residual transmission.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060150

Authors: Minyu Qin Na Young Hong Shin Woo Kim Ji Hyuk Park Seok Ju Yoo Sung Jun Park Younjoo Kim Sang Yun Cho Sook Hee Park Hyun Jun Kang Byeong Ryeon Kim Mina Lee Hyejin Hong Minjei Lee Myung Jae Hwang Sookhyun Kim Myung Hee Kim Min A. Lim Youkyoung Kim Kwan Lee

Background: Even though South Korea had eliminated measles in 2006, a localized cluster of measles occurred in a university dormitory in Gyeongsangbuk-do, South Korea, in 2024, involving 22 international students. This study aims to explore measles transmission and to inform future preventive measures. Methods: In a cross-sectional study, 299 international students from two local universities underwent a self-reported questionnaire survey and targeted serological testing by enzyme-linked immunosorbent assay two months after the cluster of measles cases. Statistical analysis used Pearson’s chi-square test, Fisher’s exact test, multivariate logistic regression, and Firth’s penalized logistic regression. Results: The overall seropositivity was 79.6%, and 78.0% among participants aged ≤30 years. Among multivariate analyses, nationality was independently associated with seropositivity (aOR up to 8.35 for Chinese students). Conclusions: These findings underscore the immunity gaps among international students, with seropositivity remaining below the 95% threshold required for herd immunity. Targeted serological screening and catch-up vaccination may help to improve immunity in mobile populations.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060149

Authors: Abdullateef Abdullah Alshehri Mohammad Y. Alqahtani Osman AE. Elnoubi Mohsen A. Qahtani Dehiyyan E. Alyami Meshal M. Alabbas Mosa M. Bahnass Abdullah Alshehari Mohammed A. Alshehri Mohammed A. Alshahrani

Brucellosis remains an important zoonotic disease in southern Saudi Arabia; however, community-level knowledge, risk-related practices, and information pathways in Najran City are insufficiently characterized. This study assessed brucellosis-related knowledge, attitudes, practices, and information pathways among adults in Najran City to inform locally relevant One Health interventions. In this cross-sectional survey, adults were recruited using stratified time–location (venue-based) sampling across community and exposure-relevant sites in Najran City. A total of 608 adults completed a structured interviewer-administered questionnaire. Composite scores were calculated for knowledge (0–21), attitude (0–22), practice (0–64), and information-source breadth (0–6). Descriptive statistics, group comparisons, correlation analyses, and multivariable linear regressions were performed. The findings suggest that participants more commonly relied on interpersonal social networks, especially family and friends, for information related to brucellosis (53.9%), whereas formal sources were less commonly reported, including health professionals (7.9%), media (4.6%), internet sources (3.3%), educational institutions (2.0%), and agricultural or veterinary organizations (1.3%). Mean knowledge scores were moderate (10.7/21), attitudes were generally favorable (19.5/22), and practice scores were moderate (36.6/64). Exposure-related behaviors remained common, particularly the consumption of unpasteurized milk or dairy products (56.6%). The breadth of information sources showed a moderate positive correlation with knowledge (rho = 0.561), whereas attitude showed only small positive correlations with knowledge and practice. Finally, knowledge was weakly and inversely correlated with practice. Among adults recruited in this venue-based sample, favorable attitudes did not consistently correspond to safer practices. These findings support practical One Health interventions, including coordinated veterinary–public health messaging on animal abortion events, safe-dairy guidance at points of sale and community venues, workplace-based training for livestock-contact groups, and referral pathways linking suspected animal cases with veterinary services and human care-seeking. Because recruitment was venue-based and non-probability, the results should be interpreted as descriptive and hypothesis-generating rather than population-representative; however, they still identify practical communication and service-delivery priorities for future intervention studies in Najran.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060148

Authors: Haoran Zhong Bowen Dong Danlin Zhu Ruiting Zhang Yuanzhao Sun Junhan Xiong Liu Gao Ke Lu Hao Li Zhiqiang Fu Jinming Liu Yamei Jin

Although schistosome eggs are widely recognized as the principal drivers of hepatic granulomatous inflammation and fibrosis, the independent effects of adult worms may be masked by strong egg antigen-mediated responses. This study aimed to investigate whether adult Schistosoma japonicum worms alter the miRNA expression profile of hepatic stellate cells and to explore the potential relevance of these changes to liver fibrosis and hepatocellular carcinoma-related processes. A non-contact Transwell co-culture system was established using paired Schistosoma japonicum worms or male worms and hepatic stellate cells. Male worms were additionally included to further assess worm-derived effects independent of egg production–related influences. Untreated hepatic stellate cells served as controls. Total RNA was extracted for miRNA sequencing, and differentially expressed miRNAs were identified. Target gene prediction, Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis, and validation using The Cancer Genome Atlas database were subsequently performed. Both paired worms and male worms significantly altered the miRNA expression profile of hepatic stellate cells. Several differentially expressed miRNAs were identified, among which hsa-miR-103a-3p showed relatively stable changes. Pathway enrichment analysis suggested that the potential target genes of hsa-miR-103a-3p were mainly enriched in AMP-activated protein kinase, mechanistic target of rapamycin, tumor necrosis factor, insulin signaling, and cellular senescence pathways. Further analysis using The Cancer Genome Atlas database showed that hsa-miR-103a-3p had diagnostic value in hepatocellular carcinoma and was associated with alpha-fetoprotein level, albumin level, Ishak fibrosis score, pathological stage, histological type, and tumor status. These findings suggest that adult S. japonicum worms may alter the miRNA expression profile of hepatic stellate cells, and that hsa-miR-103a-3p may be associated with fibrogenic responses and may have potential relevance to hepatocellular carcinoma-related processes. However, this inference is based on correlative TCGA data and does not imply a causal role in schistosomiasis-associated hepatocarcinogenesis.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060147

Authors: Nalini Jayakody Catherine A. Gordon Anjana Silva Nuwan Wickramasinghe Susiji Wickramasinghe Natasha Collinson Asela Wijayasekara Chanaka Karunarathne Nilanthi de Silva Kosala Weerakoon

Prevalence of soil-transmitted helminth (STH) infections in Sri Lanka has declined from 73.3% in 1954 to <1% in 2017, leading to revised deworming policies and discontinuation of routine deworming in three districts, including Anuradhapura, in 2019. As countries approach elimination, this study assessed human intestinal nematode infection (HINI) prevalence in Anuradhapura, a low-endemic setting, using microscopic and molecular methods. From January to November 2023, 967 primary school children were recruited and screened for HINI using direct smears, Kato–Katz, formalin ether concentration, agar plate culture, scotch tape, and qPCR. Combined microscopy and molecular prevalence was 41.2% for STH and 54.1% for HINI. The most prevalent HINI was Enterobius vermicularis (191, 24.5%), followed by Strongyloides stercoralis (120, 19.2%), Ascaris lumbricoides (113, 18.1%), Trichuris trichiura (40, 6.4%), and hookworm (43, 6.9%). Against the composite reference standard, qPCR demonstrated superior diagnostic performance across all species, achieving sensitivities of 86.7% for Ascaris, 85.0% for Trichuris, and 97.7% for hookworm, consistently exceeding those of microscopy-based methods. Correspondingly, qPCR also identified the highest infection prevalences, detecting Ascaris, Trichuris, and hookworm infections in 15.7%, 5.4%, and 6.7% of participants, respectively. All infections were low-intensity as determined by Kato–Katz. Microscopy significantly underestimates STH prevalence. In post-deworming settings, integrated surveillance including molecular diagnostics is essential. The high prevalence of S. stercoralis and E. vermicularis highlights the need for expanded surveillance and targeted interventions to support sustainable control.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060146

Authors: Yinghui Song Meng Xia Haoran Zong Wenjie Dong Qiang Wang Qin Yang Bin Zhan Yanhai Wang Limei Zhao

Alveolar echinococcosis is a life-threatening zoonotic parasitic disease caused by infection of Echinococcus multilocularis larvae. To survive within the host’s immune milieu, E. multilocularis has evolved sophisticated immune evasion strategies, including the expression of immunomodulatory proteins that regulate the host immune response. Our previous studies have demonstrated that E. multilocularis calreticulin (EmCRT) possessed strong binding ability to human complement component C1q to inhibit C1q-initiated complement activation and biological functions. To further elucidate the mechanism by which EmCRT mediates C1q inactivation and immune evasion, the precise C1q-binding site on EmCRT was identified and analyzed in this study through expression of overlapping fragments and synthesis of overlapping peptides covering the identified functional fragment. The fragment expression and functional assay narrowed down the C1q-binding site to the EmCRT-S1 fragment located between amino acids 140 and 204 of EmCRT. The precise binding site was further pinpointed to the P5 peptide (EmCRT160–174 aa) by testing the synthetic peptides covering this region. The binding of peptide P5 to C1q markedly suppressed the activation of the C1q-mediated classical complement pathway and C1q-induced neutrophil chemotaxis, production of reactive oxygen species, cathepsin G, and myeloperoxidase. These findings suggest that the C1q-binding P5 peptide of EmCRT may serve as a potential target for the development of vaccines against echinococcosis or therapeutic drugs for complement-associated inflammatory or autoimmune diseases.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060145

Authors: Solon Alberto Orlando Naomi Mora Jaramillo Ariana Montenegro Pesántez Melissa Joseth Carvajal-Capa Jose Julián Zuñiga-Velarde Silvia Tafur Miguel Angel Garcia-Bereguiain

Leptospirosis is a zoonotic disease caused by spirochete bacteria of the genus Leptospira, with a wide global distribution. In Ecuador, leptospirosis is endemic, particularly in low-resource tropical areas, and multiple animal reservoirs have been identified either in rural or urban areas, including stray dogs. In this study, a total of 81 domestic dogs presenting clinical manifestations compatible with leptospirosis were recruited at the Municipal Center for Animal Welfare in Guayaquil, Ecuador, in 2023. A survey regarding clinical, demographic, and environmental risk factors was filled in by every dog’s owner; urine and blood samples were collected for pathogenic Leptospira diagnosis by qPCR for lipL32, rrs, and secY gene targets. A very high (62.96%) positivity rate for Leptospira infection was found. Almost 90% of the dogs were not vaccinated against Leptospira. Although the animals exhibited multiple clinical signs, none showed a statistically significant association with Leptospira positivity, confirming the nonspecific presentation of the disease and its potential for misdiagnosis. The consumption of bulk food emerged as a significant environmental risk factor only in the multivariate logistic regression and not in the univariate analysis, suggesting the need for improved food safety practices. Moreover, we reported very frequent close-contact behaviors between owners and dogs. Overall, our study underscores the potential role of owned urban dogs as reservoirs of Leptospira in the city of Guayaquil in Ecuador, emphasizing the need for public health policies to increase awareness and improve diagnosis in domestic animals under a comprehensive One Health vision.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060144

Authors: Vanessa Cristina Martins Silva Lais Sampaio Azevedo Raquel Guiducci Adriana Luchs

Rotavirus A (RVA) G3P[3] genotype is widely reported in dogs and less frequently in cats, with only sporadic human cases worldwide. All reported human infections have occurred in children, suggesting increased susceptibility likely linked to close contact with pets and age-related hygiene practices. The identification of a novel genotype constellation in Brazilian canine G3P[3] strains in 2017 prompted full-genotype characterization of the historical RVA/Human-wt/BRA/IAL-R451/2011/G3P[3] strain, previously sequenced only for VP7 and VP4, to define its genomic constellation and relatedness to canine strains. All 11 segments were analyzed by RT-PCR, sequencing and phylogenetics. The rare genotype–lineage constellation G3.III-P[3]-I2.XX-R3.II-C2.V-M3.II-A9-N2.XXIV-T3.II-E3.II-H6.I, shared with Brazilian canine strains, was identified, supporting a potential common origin. RVA/Human-wt/BRA/IAL-R451/2011/G3P[3] strain showed high genetic similarity (93.2–99%) with canine, feline and canine/feline-like human strains worldwide, with six genes (VP1, VP6 and NSP2–NSP5) closely related to Brazilian dog isolates (97.6–99%), indicating its canine origin. NSP2 clustered with strains from domestic (bovine), synanthropic (rat) and human hosts, while VP7 and VP4 were associated with wildlife (bat; raccoon dog) and environmental (sewage; river water) strains, supporting interhost reassortment and highlighting aquatic environments as reservoirs for interspecies transmission. Identification of new lineages (VP1, VP3 and NSP2) within the AU-1-like backbone reflects its underexplored diversity. This novel constellation likely circulated in dogs and may spill over to humans via close contact, reinforcing a One Health approach to understand RVA zoonotic risk, especially in hotspot regions like Brazil.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11060143

Authors: Armel N. Tedjou Christophe R. Keumeni Aurélie P. Yougang Flobert Njiokou Jo Lines Sian E. Clarke Charles S. Wondji Basile Kamgang

Aedes (Ae.) aegypti and Ae. albopictus are important vectors of arboviruses. Yet their blood-feeding pattern remains poorly characterised in Africa, including Cameroon. In this study, we characterised the blood-meal sources in both species collected from vegetation, household surroundings, and animal cages across four urban sites, one rural site, and a zoo-botanical garden where humans and animals in captivity are the main hosts. Overall, Aedes mosquitoes represented about half of 10,054 female mosquitoes collected, with Ae. albopictus strongly dominating Ae. aegypti among 5001 Aedes females, and only 5.95% of females visibly blood-fed. Sequencing a 748 base pairs (bp) fragment of the cytochrome oxidase I gene from 156 blood-fed abdomens yielded 126 high-confidence host assignments, of which 98.25% were humans, indicating a strong anthropophagic pattern in both species. Unpredictably, two Ae. albopictus individuals had fed on a baboon (Papio anubis) and a frugivorous bat (Pteropodidae), as confirmed by bio informatic analyses, highlighting the species’ opportunistic blood-feeding nature and providing preliminary molecular evidence consistent with a potential bridge-vector role in this setting. Despite the extreme anthropophagy of both species observed, results indicate that Ae. albopictus could also serve as a bridge vector enabling spillover of enzootic viruses to humans, including urbanised settings where wild animals are present. These findings emphasise the urgent need for enhanced arbovirus surveillance in Central Africa using a One Health approach.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050142

Authors: Parat Boonyarangka Pheutsapha Sonthilath Sidhartha Chaudhury Virasack Banouvong Worachet Kuntawunginn Siriporn Sornsakrin Bounor Taobouathong Thavone Sinhthapaseuth Utaiwan Srichairatanakul Montri Arsanok Chanthalone Khamkong Latsamee Lattavong Raweewan Srisawat Tharinee Saleepochn Witcha Imaram Alyssa Mann Erica J. Lindroth Bouasy Hongvanthong James Jones Krisada Jongsakul

While vector control methods have successfully reduced malaria rates worldwide, such methods are not always suitable for military use. We evaluated the usability, durability, and effectiveness of permethrin-treated uniforms and metofluthrin spatial repellent in preventing mosquito bites among soldiers in the Laos People’s Army that were deployed on a 12-week field exercise. The study enrolled 173 subjects into four different groups: (1) metofluthrin-only, (2) permethrin-treated uniforms, (3) metofluthrin with permethrin-treated uniforms, and (4) a control group. We measured efficacy through self-reported survey responses and a serological test for antibodies to Anopheles salivary antigens and assessed the durability of permethrin treatment over the 12-week exercise. We found that soldiers given metofluthrin and permethrin-treated uniforms were 72% and 46% more likely to report decreased mosquito bites compared to those in the control group and that soldiers with permethrin-treated uniforms had significantly lower (p < 0.05) antibody levels to the Anopheles SG6 salivary antigen. Mass spectrometry analysis revealed that treated uniforms still contained a significant permethrin concentration that showed 50 to 100% mosquito mortality. Overall, our findings show that both metofluthrin and permethrin-treated uniforms were well-tolerated and led to significantly fewer reported mosquito bites, and that permethrin, in particular, was found to be durable throughout the 12-week field exercise and effective in reducing mosquito bite exposure, underscoring its value in military applications.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050141

Authors: Dongxue Ma Mo Zhou Shinuo Cao Eloiza May Galon-Bedonia Zhiqiang Xu Chenghui Li Xu Gao Shujiang Xue Shengwei Ji

Babesiosis is a zoonosis caused by protozoan parasites of the genus Babesia. It has a worldwide distribution and affects many kinds of mammals, principally domestic animals and humans. Because there are no safe and effective vaccines available, the treatment and control for babesiosis continues to involve the use of chemotherapeutics. For years, only a few drugs have been used for clinical treatment, namely atovaquone plus azithromycin or clindamycin plus quinine for human, and imidocarb dipropionate and diminazene aceturate for domestic animals. Although screening and developing alternative drugs are continuously pursued, only a few drugs have been prospected to have clinical applications. Of these, tafenoquine has shown wide and potent antibabesial activity, offering a new option to control babesiosis. This article aims to present the current clinical therapeutic strategies for babesiosis and their limitations, as well as the prospect of tafenoquine as a promising drug to treat babesiosis.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050140

Authors: Karen Santos Lima Adriane Paz Rocha Alice Lanna Damásio Castro Anna Carolina Faria Moreira Gomes Tavares Flávia Patrícia Sena Teixeira Santos Gilda Aparecida Ferrreira Livia Barbara Cordeiro Alves Josiane Lino dos Santos Frattari Juliana Froeseler Fittipaldi Lucas Borba Paulino Coelho Maria Fernanda Brandão de Resende Guimarães Pedro Ribeiro de Jesus Almeida Último Libânio Costa Cristina Costa Duarte Lanna Gustavo Gomes Resende Mauro Martins Teixeira

Chronic chikungunya disease (CCD) affects approximately 30–50% of infected individuals and is associated with persistent inflammatory arthritis, chronic pain, and long-term functional disability. We conducted a prospective observational cohort study including 584 patients with laboratory-confirmed chikungunya infection, evaluated between 3 and 12 months after acute infection, to better understand the natural history, risk factors, clinical presentation, and treatment patterns of CCD. Here, we present a cross-sectional analysis derived from this cohort. Older age, female sex, and higher body mass index were identified as major risk factors for CCD. Four distinct clinical phenotypes were identified: Axial (12.2%), defined by inflammatory axial pain regardless of peripheral manifestations; Oligoarthritis (18.1%), defined by fewer than four swollen joints; Polyarthritis (10.6%), defined by four or more swollen joints; and Pain without Swelling (70.4%), characterized by myalgia and/or arthralgia in the absence of objective inflammatory findings on physical examination. The axial phenotype could overlap with peripheral phenotypes, whereas oligoarthritis, polyarthritis, and pain without swelling were mutually exclusive categories. These phenotypes differed substantially in symptom burden and clinical impact. Patients with the Pain without Swelling phenotype had longer symptom duration, whereas Axial and Polyarthritis phenotypes were associated with greater functional impairment and higher disease burden. These findings reinforce the clinical heterogeneity of CCD and support the potential value of phenotype-based approaches for clinical management and future therapeutic research.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050139

Authors: Arshad Rizvi Yash Gupta

Mycobacterial diseases, particularly tuberculosis (TB), continue to impose a substantial global health burden, disproportionately affecting populations in low- and middle-income countries [...]

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050138

Authors: Anna Papa Katerina Tsioka Styliani Pappa Danai Pervanidou Constantina Politis Kostas Stamoulis Vassiliki Bakaloudi

Usutu virus (USUV) is a mosquito-borne flavivirus, widely distributed in Central Europe, where it causes avian outbreaks with large-scale mortality. Although most human infections are asymptomatic or mild, the reports of USUV neurologic infections are increasing, especially among immunocompromised patients. Cross-reactivity in serological and molecular assays is often seen between USUV and the genetically and antigenically related West Nile virus (WNV). Here, we report the first USUV infection in Greece in an asymptomatic blood donor who tested positive in the automated nucleic acid test during screening for WNV, which is endemic in the country. Following the blood donation surveillance plan, a serum sample taken two weeks post-donation was tested for WNV IgM and IgG antibodies. The borderline index of the IgM antibodies, combined with negative result for IgG antibodies, raised the suspicion of molecular cross-reactivity with USUV. Although the USUV-specific PCR in donor’s plasma was negative, its result was positive following amplification of the virus in cell culture, as USUV RNA was detected in the culture supernatant confirming the USUV infection. Whole genome sequence was taken using an Ion Torrent next-generation sequencing platform. Phylogenetic analysis showed that the Greek strain clusters within the USUV Europe 2A genetic lineage. The detection of USUV human infection in Greece prompts for surveillance studies to elucidate its epidemiology and ecology in the country.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050137

Authors: Nevra Karaca Biçakçi Ayşe Çalmaz Merve Ayyildiz Akin Ching Siang Tan Jayanthi Barasarathi Babatunji E. Oyinloye Annaev Umidjon Kuvonchbek Egamberdiyev Intizor Avazmetova

Insecticide-treated nets (ITNs), particularly long-lasting insecticide-treated nets (LLINs), are important for malaria control; however, the rise of insecticide resistance, behavioral adaptations in mosquito vectors, and diminishing net durability may affect their efficacy. The objective of this systematic literature review and meta-analysis to synthesize recent epidemiological evidence (2021–2025) on the correlation between ITN/LLIN use and Plasmodium falciparum infection prevalence and to explore sources of heterogeneity across populations, settings, and type of nets. Searches across PubMed, Scopus, and Web of Science yielded 3151 records, of which 10 met the inclusion criteria. Two separate meta-analyses were performed for crude and adjusted effect estimates using random-effects models. The crude-effects meta-analysis included six studies comprising 7466 participants and yielded a pooled odds ratio of 0.67 (95% CI: 0.42–1.07; p = 0.078), indicating no statistically significant association between ITN/LLIN use and P. falciparum infection. Significant heterogeneity was observed (I2 = 79.8%), which was partially explained by population type (59.3%) and study design (36.1%). Subgroup analysis revealed comparable infection prevalence–based associations for ITNs (OR = 0.72) and LLINs (OR = 0.59) use. Assessment of publication bias indicated slight asymmetry; however, the trim-and-fill adjustment did not significantly change the conclusions. The adjusted-effects meta-analysis, comprising nine studies, yielded a non-significant pooled effect (aOR = 0.88; 95% CI: 0.42–1.86; p = 0.71) with substantial heterogeneity (I2 = 88.7%). Meta-regression analyses indicated that effect estimates varied by population group and country, with statistically significant modifiers observed for children under five years (p = 0.0098) and for studies conducted in Uganda (p = 0.0378). The type of net contributed to variation between studies, with insecticide-treated nets (ITNs) exhibiting lower pooled odds than long-lasting insecticide-treated nets (LLINs) (p = 0.0415). Overall, this meta-analysis found no conclusive evidence of a statistically significant association between ITN/LLIN use and P. falciparum infection in contemporary epidemiological studies. The substantial heterogeneity across settings underscores the context-dependent nature of observed associations and highlights the need for integrated vector-control strategies and continued evaluation of net technologies under conditions of increasing resistance.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050136

Authors: Félix Alain Botovola Miraimila Véronique Chevalier Peter N. Thompson

Rift Valley fever (RVF) is a viral zoonosis endemic in Madagascar, threatening human and animal health as well as the economy. Trade-related livestock movements are a major factor in the spread of RVF virus. While previous RVF research in Madagascar has focused on farmers or general ecology, this study is the first to specifically target livestock traders, the primary drivers for long-distance viral spread, in the Alaotra Mangoro endemic hotspot. This study aimed to assess the level of knowledge, prevailing attitudes and current practices regarding RVF among people engaged in livestock trade in the Alaotra Mangoro region, as well as the factors associated with these KAPs. A descriptive and analytical cross-sectional survey was conducted among 406 livestock traders in five districts of the Alaotra Mangoro region, using a structured questionnaire. A multi-stage sampling approach was employed, utilising purposive selection of markets followed by snowball sampling to reach informal traders often missed by traditional surveys. Generalised linear mixed models were used to analyse factors associated with KAPs regarding RVF. Awareness of RVF was very low (only 18.5% respondents had heard of it), with significant regional disparities (0% in Anosibe An’Ala versus 51.6% in Moramanga). Veterinarians (15.5%), family (12.8%), radio (9.6%) and neighbours (9.6%) were the main sources of information. Understanding of symptoms and modes of transmission (particularly mosquito bites) was limited. Higher levels of education (OR = 181.6; 95% CI: 29.9–1123.7; p < 0.001) and older age (50–60 years) were associated with better knowledge. Proactive attitudes were scarce (21.4%), although more than half (53.4%) believed that RVF is a real disease. Perception of personal risk and the contribution of livestock trade to the spread of the disease was low. However, confidence in animal vaccination was relatively high (60.3%). Preventive practices were highly inadequate. The majority did not wear protective equipment when handling sick animals (94.6%) and rarely avoided touching aborted foetuses (12.6%). Less than half (48.3%) expressed a willingness to report sick or dead animals, and nearly half admitted to having sold or purchased sick livestock (49.5%). Cooking meat (95.1%) and using mosquito nets (74.1%) were the only well-established practices. More than half of respondents (57.9%) lived more than 5 km from veterinary services, and cost was the most frequently cited barrier to consultation. Participation in awareness campaigns was virtually non-existent (5.4%). Results revealed critical gaps in KAP that may contribute to the persistence of RVF. A “One Health” approach is imperative, integrating human, animal and environmental health.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050135

Authors: Tian Ren Kailun Ma Xinmiao Lai Jizheng Chen Changgui Li

Human metapneumovirus (HPMV) is a significant pathogen that causes lower respiratory tract infections. Given the weak immunogenicity thereof, and the few relevant studies, the utility of the viral membrane protein G as a vaccine remains controversial. In this study, the G extracellular domain (RMG) of HMPV was expressed either alone or fused with the cholera toxin B subunit (CTB) and “cross-reacting material 197” (CRM197) carrier proteins (giving G-CTB/G and CRM197), to enhance immunogenicity. The non-glycosylated G protein (REG) expressed in Escherichia coli served as a control. SDS-PAGE and anti-His tag Western blotting verified that each protein was successfully expressed and correctly identified. BALB/c mice were immunized with each protein and subjected to challenge with HMPV. The results showed that, although immunization with RMG alone failed to induce potent neutralizing antibodies, it modestly reduced viral loads in the lungs of mice. However, the pathological damage caused by lung inflammation was more aggravated than that of the control challenge group. The level of specific IgG antibody induced by the recombinant G-CTB was significantly higher than that elicited by RMG. Compared to the RMG group, the viral load in the lungs of the G-CTB group tended to be reduced. Also, the damage caused by lung inflammation was significantly alleviated. Our study proves that HMPV G may be a valuable antigen in terms of HMPV vaccine development and offers a promising strategy for modulating the immunogenicity and safety thereof.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050134

Authors: Selene M. Gutierrez-Rodriguez Ivan Cordova-Guerreo Laura Diaz-Rubio Jesus A. Davila-Barboza Iram P. Rodriguez-Sanchez Beatriz Lopez-Monroy Sergio A. Galindo-Rodriguez Adriana E. Flores

The increasing prevalence of insecticide resistance in Aedes aegypti threatens the effectiveness of chemical vector control and highlights the need for alternative approaches targeting mosquito behavior. This study evaluated the oviposition deterrent and larvicidal activity of Salvia munzii essential oil against insecticide-susceptible (New Orleans; NO) and insecticide-resistant (Escobedo) Ae. aegypti strains. The essential oil, dominated by camphor (29.6%), 1,8-cineole (20.8%), and limonene (16.7%), was assessed through laboratory and semi-field bioassays. Larvicidal activity yielded LC50 values of 184.38 µg mL−1 for the susceptible strain and 305.04 µg mL−1 for the resistant strain, with a resistance ratio of 1.65, indicating susceptibility. Oviposition deterrence was quantified using the Oviposition Activity Index (OAI), and median repellent concentrations (RC50) were estimated. Under laboratory conditions, RC50 values were 1.65 µg mL−1 for the NO strain and 1.73 µg mL−1 for the Escobedo strain. Under semi-field conditions, the RC50 for the Escobedo strain decreased to 0.62 µg mL−1. Deterrent activity increased with concentration and persisted for up to 40 days, particularly at higher doses. These results demonstrate that S. munzii essential oil exhibits both larvicidal and oviposition deterrent activity against Ae. aegypti, including a pyrethroid-resistant population, under laboratory and semi-field conditions. The findings support further evaluation of S. munzii essential oil as a potential complementary tool for integrated vector management strategies.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050133

Authors: Juan Camilo Motta Manuel Alejandro Delgado Jacqueline Mugnier-Quijano

Background: Strongyloides stercoralis is a soil-transmitted helminth capable of establishing chronic infection through an autoinfective cycle, with the potential to progress to life-threatening hyperinfection, particularly in immunocompromised individuals. Case Presentation: We report the case of a 70-year-old man from an endemic region in Colombia with metastatic urothelial carcinoma who developed hyperinfection syndrome following corticosteroid therapy for spinal cord compression. The patient presented with progressive respiratory failure and diffuse alveolar hemorrhage. Chest imaging showed bilateral ground glass opacities, and bronchoalveolar lavage revealed numerous larvae consistent with S. stercoralis, confirming the diagnosis. Despite supportive care and broad-spectrum antimicrobial therapy, the patient experienced rapid clinical deterioration and died. Conclusions: This case highlights the importance of considering strongyloidiasis in the differential diagnosis of diffuse alveolar hemorrhage in endemic settings, particularly in patients receiving corticosteroids. Early recognition and timely treatment are essential to reduce the high associated mortality. Preventive strategies, including targeted screening or empiric ivermectin administration prior to immunosuppression, should be considered in high-risk populations.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050132

Authors: Manana Dewage Sankani Vishvara Kularathna Senanayake Abeysinghe Mudiyanselage Kularatne

Background: Leptospirosis is a globally prevalent zoonosis with significant morbidity and mortality, especially in tropical regions like South Asia. In its severe form, the disease often leads to multiorgan dysfunction, with pulmonary haemorrhage being a major cause of death. Evidence supporting specific treatments for severe leptospirosis with pulmonary involvement remains limited. Recent studies suggest that immunomodulatory therapies, such as therapeutic plasma exchange (TPE), may offer survival benefits. This case series explores the application and outcomes of TPE in patients with severe leptospirosis at a tertiary care hospital in Sri Lanka. Methods: We studied a case series involving nine patients with confirmed severe leptospirosis and multiorgan involvement from September 2021 to October 2022. All patients received standard care, including intravenous antibiotics and methylprednisolone. TPE was initiated in all nine patients based on clinical severity, particularly in the presence of pulmonary haemorrhage. Clinical, laboratory, and radiological data were collected from patient records and follow-up. Leptospirosis diagnosis was confirmed through ELISA IgM testing. TPE decisions were made by a multidisciplinary team. Results: Of the nine patients who received TPE, seven survived (78%). Pulmonary haemorrhage was the primary indication for TPE in all cases. All patients had multiorgan involvement: renal failure (89%), hepatic dysfunction (55%), and myocarditis (67%). Mortality was associated with inotropic-dependent myocarditis and mechanical ventilation at TPE initiation. Patients requiring intubation had a 50% mortality rate, compared to 14% in those who were not intubated. Non-survivors also had significantly elevated lactate levels (>4 mmol/L) and worsening acid–base status. Four patients required dialysis: three survived. Conclusions: Early initiation of TPE may be safe and beneficial in severe leptospirosis, and future randomised controlled studies are necessary to examine its benefits further. These findings are hypothesis-generating for further research, particularly on patient selection for TPE.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050131

Authors: Jalil Nejati Abedin Saghafipour Mahsa Sarvi Rubén Bueno-Marí

Aedes mosquitoes are among the most important vectors of arboviral diseases such as dengue, Zika, and chikungunya. Mapping their geographic and temporal patterns is essential for understanding disease risk and guiding vector control. This systematic review provides an updated synthesis of the spatial and temporal distribution of Aedes species across Iran. A comprehensive search of international (PubMed, Scopus, Web of Science) and national (SID, IranMedex, Magiran) databases was performed for studies published between 1980 and 2025. Eligible publications reporting the occurrence or distribution of Aedes mosquitoes were screened according to PRISMA guidelines. Data were extracted and analyzed descriptively to identify long-term spatial and temporal trends. Sixty-six studies met the inclusion criteria, covering more than 20 provinces and examining over 390,000 mosquito specimens. Aedes caspius was the dominant species nationwide, reflecting its high ecological adaptability. Invasive vectors, Ae. aegypti and Ae. albopictus, were recorded mainly in southern coastal provinces and, more recently, in the humid northern regions. Over time, surveys have evolved from scattered faunistic reports to systematic nationwide monitoring, revealing clear patterns of ecological expansion driven by climatic and environmental factors. Increasing reports, broader geographic distribution, and adaptability to diverse ecological settings indicate an ongoing expansion of Aedes mosquitoes in Iran. While these developments reflect successful entomological surveillance and public health efforts, enhanced preparedness and continuous monitoring are essential to manage potential Aedes-borne outbreaks effectively.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050130

Authors: Theos Dieudonne Benimana Martin Habimana Jean de Dieu Harerimana Eric Mugabo Thierry Sebakunzi Patrick Niyonshuti Valens Rwema Muhammed Semakula Seung-sik Hwang

Background: Diarrheal disease remains a major and persistent cause of morbidity and mortality in Rwanda, with substantial seasonal surges that strain routine services; however, transparent and operationally interpretable national forecasting has been underused for age-stratified burden. Methods: We analyzed the Rwanda Health Management Information System (HMIS) monthly diarrhea case counts (January 2015–December 2025), stratified by age group (under-five and five-and-above), and developed validated Seasonal Autoregressive Integrated Moving Average (SARIMA) forecasts for January 2026–December 2027. Stationarity was assessed using the Augmented Dickey–Fuller test and addressed through differencing. Candidate models were selected via rolling 5-fold cross-validation: Root Mean Square Error (RMSE), Mean Absolute Error (MAE), Akaike Information Criterion (AIC), Bayesian Information Criterion (BIC), and Mean Absolute Percentage Error (MAPE) and confirmed via Ljung–Box residual diagnostics, and benchmarked against seasonal naïve, Exponential Smoothing State-Space (ETS), and Seasonal-Trend decomposition using Loess (STL) + drift reference models. Results: Rwanda recorded 6,309,098 diarrhea cases during 2015–2025, with 49.2% among under-fives; while absolute counts were higher in those aged ≥5 years, risk remained consistently higher in under-fives (91.7–229.5 per 1000) than in those ≥5 years (17.9–34.3 per 1000). Both series showed strong annual seasonality with recurrent peaks in August–November, and forecasts suggest this pattern will persist through 2026–2027. Conclusions: These findings suggest a provisional seasonal (pre-peak, peak, and post-peak) preparedness framework and age-differentiated planning signals, underscoring that burden and risk are not inter changeable across age groups.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050129

Authors: Xiaoming Liu Howard Takiff Hui Jiang Weimin Li

Background: Childhood tuberculosis (TB) is a major but underappreciated threat to human health. Because diagnosis of tuberculosis in children is difficult, there are a lack of accurate global statistics. This study aimed to comprehensively assess the long-term global, regional, and age-specific burden of childhood TB from 1990 to 2021, to examine its temporal trends and socioeconomic inequalities, and to project future patterns through 2045. Methods: We used incidence and mortality data from the GBD 2021 database for TB in children ages 0–14 years from 1990 to 2021. Children were stratified into three age groups—<5, 5–9 and 10–14 years—and classified by region and Socio-Demographic Index (SDI). Multiple statistical approaches were employed, including average annual percentage change and Bayesian age-period-cohort models, to analyze spatiotemporal trends in disease burden and generate projections for the next 20 years. We used decomposition analysis to separate demographic from epidemiological drivers and concentration indices to quantify socioeconomic inequalities. Results: In 2021 there were, globally, an estimated 759,300 incident cases of childhood TB and 70,659 deaths. Since 1990, childhood TB incidence and mortality rates have declined at average annual rates of 2.61% and 4.48%, respectively. The SDI showed a significant negative correlation with both incidence and mortality of childhood TB (p < 0.05). In 2021, 78.01% of childhood TB deaths were in children under 5 years of age, and over 80% of global childhood TB deaths occurred in Sub-Saharan Africa. Epidemiological interventions were partly offset by rapid population growth in low-SDI regions. The trends show that the incidence and mortality will continue to decline through 2045, but not enough to meet the goal of eliminating childhood TB by 2035. Conclusions: Global efforts should adopt an age-specific framework that prioritizes universal preventive treatment to eliminate mortality in children under 5 years, and implements active case finding to reduce transmission chains among children 5–14 years. Sustaining the decrease in the TB burdens of low-SDI regions requires international financing strategies attuned to expanding populations to ensure epidemiological success is not erased by demographic growth.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050128

Authors: Upeksha S. Wanigarathna Senaka Rajapakse Sisira L. Pathirana Shiroma M. Handunnetti Andreas Nitsche Narmada Fernando

Dengue infection remains a major global health concern, with a subset of patients progressing from self-limited dengue fever to severe disease characterised by plasma leakage, shock, and organ dysfunction. The dengue non-structural protein 1 (NS1), a multifunctional glycoprotein expressed on infected cells and secreted into circulation, has emerged as a key mediator linking viral infection to immune-driven vascular pathology. This review synthesises experimental, animal, and human clinical evidence on NS1-driven immunopathogenesis, focusing on mechanisms leading to endothelial dysfunction and increased vascular permeability. NS1 modulates the complement system in a context-dependent manner, contributing to immune evasion by inhibiting terminal complement complex formation, while also promoting antibody-dependent complement activation associated with severe disease. Additionally, NS1 directly disrupts endothelial barrier integrity through disruption of adherens and tight junction architecture, Ang-2/Tie2 imbalance, activation of RhoA/ROCK (RhoA/Rho-associated coiled-coil-containing protein kinase) signalling, and enzymatic degradation of the endothelial glycocalyx, with further amplification through inflammatory mediators. In addition, evidence shows that NS1 activates innate immune signalling, perturbs platelet biology and haemostasis, and forms pro-inflammatory complexes with lipoproteins. Moreover, anti-NS1 antibodies may be both protective and pathogenic. Collectively, these data position NS1-linked pathways as rational targets for adjunctive therapies and next-generation vaccines aimed at preventing vascular leakage and severe dengue infection.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050127

Authors: Mahmud Azbida Sana Ferjani Omar Elahmer Rmadhan Osman Salem Shenaisheh Amal Barakat Salma Abid Adem Eljerbi Abdulwahab Kammon Ameni Sallemi Haider El-Saeh Ilhem Boutiba-Ben Boubaker Ibrahim Eldaghayes

Influenza sentinel surveillance in Libya was formally established in 2022 by the Libyan National Center for Disease Control (NCDC). Between 2022 and 2024, a total of 1864 nasopharyngeal specimens were collected from patients presenting with influenza-like illness and tested using the GeneXpert for influenza A virus, influenza B virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and respiratory syncytial virus (RSV). Influenza A virus was detected in 21.1% (393/1864) of samples and influenza B virus was detected in 5.4% of samples (100/1864). SARS-CoV-2 and RSV were identified in 11.6% (216/1864) and 4.1% (77/1864) of specimens, respectively. A subset of 22 influenza A-positive samples was selected based on sample availability and sufficient remaining volume after the initial test for confirmatory testing and further molecular characterization. Real-time RT-PCR subtyping identified 11 A(H1N1)pdm09 and four A(H3N2) viruses. Whole-genome sequencing was successfully performed for 11 isolates, followed by phylogenetic analysis. Genetic characterization revealed that all A(H1N1)pdm09 viruses belonged to clade 6B.1A.5a.2a (5a.2a), while A(H3N2) viruses clustered within clade 3C.2a1b.2a.2a.3a.1 (2a.3a.1) were based on hemagglutinin gene mutations. No neuraminidase mutations associated with antiviral resistance were detected. This study represents the first molecular and phylogenetic characterization of circulating human influenza viruses in Libya, with sequence data submitted to the Global Initiative on Sharing All Influenza Data (GISAID) to establish baseline genetic data for influenza viruses in Libya.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050126

Authors: Nguyen Van Hiep Tatiana A. Bondarenko Le Thi Lan Anh Olga A. Stukolova Luong Thi Mo Kseniia A. Sycheva Vien Chinh Chien Alex L. Viskontene Nguyen Thi Dung Dmitriy V. Dubrovskiy Truong Xuan Toan Marina I. Sokolova Truong Thi Ngan Irina P. Lisyukova Daria D. Skripnichenko Viktoria P. Bulanenko Yulia V. Fedakova Vasily G. Akimkin Marat T. Makenov

The distribution of medically significant ticks in Vietnam requires ongoing monitoring. This study presents data on tick distribution and molecular screening for Borrelia spp. and Coxiella burnetii DNA. Ticks were collected from domestic animals and vegetation in four provinces over the period of 2024–2025. Species identification was performed based on morphology and confirmed by sequencing mitochondrial COI and 16S rRNA genes. A total of 2347 ticks were collected, representing eight species from the genera Haemaphysalis, Rhipicephalus, and Amblyomma. The study provides new distribution records for H. bispinosa, H. cornigera, A. integrum, and several rarely reported species (H. lagrangei, H. hystricus, and H. wellingtoni). PCR screening revealed a relatively high detection rate of Borrelia DNA in H. cornigera from Cao Bang province. Sequencing identified the pathogen as B. theileri, the agent of bovine borreliosis. Borrelia theileri was also detected in R. microplus in other regions, indicating wider circulation. PCR screening for Coxiella burnetii was positive for 13 ticks from cattle in Cao Bang province. To rule out false-positive results due to detection of DNA from Coxiella-like endosymbionts, we sequenced a fragment of the IS1111 element for three positive samples. The sequences confirmed that the DNA belongs to bacteria of the genus Coxiella, but the data do not allow confident assignment to C. burnetii at the species level. These positive ticks originated from eight neighboring households, suggesting a potential localized focus that requires further assessment in livestock and humans to determine the epidemiological significance. This research enhances the understanding of Vietnam’s tick fauna and associated pathogens of medical and veterinary importance.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050125

Authors: Ayenew Genet Kebede Zewdu Bishaw Aynalem Aragaw Egziabherfenta Tadele Belachew Tegegne Asrat Yazew Betelhem Mekonnen Alem Lalem Tilahun Tamene Fetene Terefe Getachew Amare Atsedemariam Andualem Sewunet Ademe Yonas Wondie

Background: An outbreak of Marburg virus in Jinka Town, Southern Ethiopia, has raised significant concern regarding the potential spreading of disease throughout the country. Healthcare workers play a crucial role in early prevention and control of such an outbreak. However, the knowledge, attitudes, and preparedness of healthcare workers regarding Marburg virus disease have not been assessed yet, despite these factors being critical for early prevention and control of an outbreak. This study aimed to assess the knowledge, attitude, and preparedness regarding Marburg virus disease among healthcare workers in Awi Zone public hospitals, northwest Ethiopia, in 2026. Methods: An institutional-based cross-sectional study was conducted among healthcare workers in Awi Zone public hospitals from 26 December 2025 to 10 January 2026. A simple random sampling technique was used to select 394 participants. The data were collected using a pre-tested, structured self-administered questionnaire. The data were entered into Epi-data version 4.6 and analyzed using SPSS version 25. Results: A total of 394 healthcare workers participated in this study. The mean age of the participants was 32.9 ± 4.87 years. The study revealed that 47.7% (95% CI: 42.78–52.62%) and 61.2% (95% CI: 56.4–66%) of participants had good knowledge and a positive attitude towards Marburg virus disease, respectively. However, only 20.3% (95% CI: 16.34–24.26%) demonstrated good preparedness for the Marburg virus outbreak. Conclusions: The study revealed that the majority of healthcare workers had positive attitudes and suboptimal knowledge but critically low preparedness regarding Marburg virus disease prevention and control in Awi Zone public hospitals, northwest Ethiopia. Hence, healthcare workers who are frontline staff for outbreak prevention and control, Awi zone health departments and hospital administrators should be provided with targeted training preparation, training for implementing emergency preparedness plans, and essential infection prevention protocols to improve readiness for a potential outbreak.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050124

Authors: Fabrício Silva Pessoa

A decade has elapsed since the first recognized cluster of congenital anomalies associated with Zika virus (ZIKV) was reported in Brazil in 2015, culminating in the formal delineation of Congenital Zika Syndrome (CZS) as a specific pattern of birth defects. This narrative review examines the ten-year trajectory of CZS as a tropical infectious disease, from its initial emergence and public health emergency declaration by the World Health Organization (WHO) in February 2016, through evolving epidemiological, clinical, and scientific understanding. CZS is characterized by a spectrum of severe neurological manifestations—including microcephaly, subcortical calcifications, malformations of cortical development, ventriculomegaly, and corpus callosum abnormalities—alongside ophthalmic, auditory, and musculoskeletal complications. Transmitted primarily by Aedes aegypti mosquitoes in tropical and subtropical regions, ZIKV disproportionately affects low- and middle-income countries in Latin America, Africa, and Southeast Asia, underscoring its nature as a quintessential tropical disease linked to poverty, inadequate vector control, and health inequity. Over ten years, substantial advances have been made in understanding ZIKV pathogenesis, neurodevelopmental outcomes, diagnostic criteria, and multidisciplinary clinical management of affected children. In the therapeutic and preventive domain, over 45 vaccine candidates have been identified, with 16 reaching Phase 1 or 2 clinical trials by late 2025, though no licensed vaccine or specific antiviral therapy yet exists. This review contextualizes CZS within the broader framework of neglected tropical diseases, evaluates its global and family-level burden, and critically appraises progress and remaining gaps in clinical care, vaccination, and vector control over the past ten years.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050123

Authors: Agrin Zauyani Putri Ajib Diptyanusa Regina Tiolina Sidjabat Yatinawati Yatinawati Yety Intarti Irma Surya Kusuma Khadijah Qurrata Ayun Trijoko Yudopuspito Muhammad Anwar Simanullang Dwi Martanti Achmad Naufal Azhari Herdiana Herdiana Yullita Evarini Yuzwar

Indonesia is approaching the ‘last mile’ of elimination for several skin-related neglected tropical diseases (skin NTDs): notably, leprosy, yaws and lymphatic filariasis (LF). However, persistent transmission in selected districts highlights systemic weaknesses in surveillance. This paper aimed to analyse the health system, operational and sociocultural barriers to integrated skin NTDs surveillance in Indonesia. A descriptive analysis of the national programmatic review of integrated skin NTDs was conducted in 2024, using a mixed-methods descriptive evaluation based on routine data and thematic analysis. Comparative case studies of the Belitung, Mimika and Sorong Selatan Districts were conducted using routine data, programme reports, and structured observations at primary health centres, district health offices and laboratories. Qualitative insights from programme managers, health workers and communities were thematically analysed. Integrated surveillance was constrained by fragmented governance, inflexible financing, and uneven workforce capacity, alongside operational challenges like delayed detection and geographic inaccessibility. Furthermore, sociocultural factors such as stigma and population mobility, combined with zoonotic LF transmission in Belitung, significantly undermine effectiveness and long-term programmatic sustainability. Despite strong national policy commitment and substantial progress in disease elimination, significant gaps remain between integration frameworks and operational realities at the district level. Accelerating skin NTDs elimination in Indonesia requires context-adapted integration, strengthened digital surveillance, sustained subnational financing, workforce capacity building and, in zoonotic settings, a One Health approach. Addressing these factors is essential for achieving and sustaining elimination in the last mile. Indonesia has achieved substantial progress across major skin NTDs, while also revealing persistent gaps that threaten the sustainability of elimination gains.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050122

Authors: Solange Milolo Tshilumba Ynke Larivière Trésor Zola Matuvanga Armand Mutwadi Danoff Engbu Germain Kapour Gwen Lemey Maha Salloum Maeliss Champagne Daddy Mangungulu Pierre Van Damme Hypolite Muhindo-Mavoko Vivi Maketa Tevuzula Joachim Mariën Martine Peeters Jean-Pierre Van Geertruyden Patrick Mitashi-Mulopo

Background: Malaria remains hyperendemic in the Democratic Republic of the Congo, while arboviral infections are increasingly reported but remain under-surveilled, particularly in remote regions. Overlapping ecological niches and non-specific clinical presentations complicate case management and surveillance. Methods: A cross-sectional door-to-door survey was conducted in December 2023 in Inkanamongo village (Lokolia Health Area, Boende Health Zone, Tshuapa Province). Blood samples were collected from 379 adults; malaria infection was assessed by using HRP2-based rapid diagnostic tests, and arboviral IgG antibodies were measured on dried blood spots using Luminex® multiplex immunoassay. Sociodemographic data were collected via standardized questionnaires. Results: Malaria prevalence was 51.7% (95%CI: 46.7–56.7). Overall arboviral seroprevalence reached 78.4% (95%CI: 73.1–81.5), dominated by O’nyong-nyong virus, 42.8% (95%CI: 37.6–47.5), Rift Valley fever virus, 32.0% (95%CI: 26.9–36.2), and chikungunya virus, 23.4% (95%CI: 19.0–27.4). Concurrent malaria infection and arboviral exposure were observed in 40.4% (95%CI: 35.6–45.4) of participants. No sociodemographic factors were significantly associated with co-exposure in the multivariable analysis. Conclusions: Substantial co-exposure of malaria and multiple arboviruses occurs in this remote Congo Basin setting. Integrated surveillance and improved diagnostics are urgently needed to guide febrile illness management and preparedness in under-resourced regions.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050121

Authors: Zhao Xuan Low Nghiem Nguyet Thu Truong Tuyet Mai Tran Thanh Duong Pouya Hassandarvish Vunjia Tiong Nguyen Thi Thu Thuy Nguyen Thi Tham Cap Minh Duc Osamu Kanauchi Sazaly Abubakar

The rising health threat to healthcare workers (HCWs) demands innovative preventive solutions that are affordable, scalable, and easy to deploy, especially in resource-limited settings. This present study investigated the effects of Lactococcus lactis strain Plasma (LC-Plasma) intake on upper respiratory infection (URI)-like symptoms in a healthy healthcare-associated population in Vietnam. A randomized, placebo-controlled, double-blind, parallel-group clinical trial was conducted, integrating clinical symptom analysis with ex vivo immune response analysis of peripheral blood mononuclear cells (PBMCs). The study found that after 4 weeks of continuous oral LC-Plasma intake, participants in the LC-Plasma group had significantly fewer cumulative days of fever and fatigue than those in the Control group. Increased expression of interferon-stimulated genes (ISGs), particularly MxA, was observed in PBMC cultures from the LC-Plasma intake group. In PBMCs from LC-Plasma recipients classified as low IFN-α responders, the addition of CpG ODN 2216, a mild TLR9 agonist, significantly enhanced interferon-α production. Humoral factors derived from LC-Plasma-primed PBMCs demonstrated inhibitory effects on dengue virus replication in Huh-7 cells. These results suggest that LC-Plasma consumption by the healthcare-associated population reduces the severity of viral infection symptoms, notably fever and fatigue. Elevation of systemic antiviral immunity through activation of plasmacytoid dendritic cells (pDCs) to produce IFN-α and upregulation of ISG expression could be the mechanisms of action. Lactococcus lactis LC-Plasma supplementation, hence, presents a promising adjunctive approach to alleviate the burden of URI-like symptoms in low-resourced vulnerable populations.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050120

Authors: Tatjana Munko Vesna Vukičević Lazarević Jelena Barišić Marina Perković Tanja Vignjević

Objectives: Diagnostic delay in pulmonary tuberculosis remains a significant barrier to effective disease control, even in low-incidence settings. This study aimed to identify factors associated with total delay and its components among adults with pulmonary tuberculosis in such a setting. Patients and methods: A retrospective observational study was conducted on adults with pulmonary tuberculosis treated at a tuberculosis care centre in Croatia. Total delay was defined as the interval between symptom onset and treatment initiation. Data were collected through structured patient interviews using a standardized questionnaire, medical record review, and routine tuberculosis notification forms from the national public health registry. Sociodemographic and clinical predictors were evaluated using multivariable linear and logistic regression analyses. Results: Among 116 participants, the median total delay was 85 days (interquartile range 48.5–155.3). Rural residence was the strongest independent predictor, with patients experiencing an 88% longer delay than urban residents (p = 0.006). Individuals living in one-person households had a 49% longer delay (p = 0.047). Absence of chest pain was associated with shorter delay (−38%, p = 0.032) and lower odds of extreme delay (odds ratio 0.39, p = 0.047). Retired status independently predicted prolonged health system delay (42.1 days longer) and treatment delay (3.4 days longer). Conclusion: Prolonged delay may become increasingly important in the context of population ageing and changing household structures. Targeted strategies focused on rural, retired, and people living in one-person households may improve the timeliness of tuberculosis detection in settings where declining incidence can reduce clinical suspicion.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050119

Authors: Andrés Esteban Barragán-Peña Darwin Paredes-Núñez Fabiola Jimenez Valenzuela Solon Alberto Orlando Elsy Carvajal Angel Sebastian Rodriguez-Pazmiño Miguel Angel Garcia-Bereguiain

Early confirmation of leptospirosis is essential for prompt antimicrobial treatment, and PCR-based diagnosis has been reported as a highly sensitive method during the acute phase in the first week since the symptom’s onset. We evaluated the diagnostic performance of two commercial real-time PCR assays—Viasure Leptospira Real-Time PCR (Certest Biotec, Spain) and Genesig Advanced Leptospira spp. (Primerdesign, UK) against an in-house qPCR assay targeting lipL32 as the reference method. A retrospective comparative evaluation was conducted on 235 human EDTA-blood samples obtained during the acute phase of clinical presentation suspected of leptospirosis. The in-house qPCR reference assay detected 55 positive and 180 negative samples, and both commercial kits accurately classified every specimen, achieving 100% sensitivity (95% CI: 93.5–100), 100% specificity (95% CI: 98.0–100), and 100% overall accuracy. In conclusion, both commercial qPCR kits offer high accuracy for the early detection of pathogenic Leptospira in human blood samples.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050118

Authors: Penchom Janwan Lakkhana Sadaow Patcharaporn Boonroumkaew Rutchanee Rodpai Oranuch Sanpool Tongjit Thanchomnang Pokkamol Laoraksawong Pewpan Maleewong Intapan Wanchai Maleewong

Background: To address the significant burden of helminthiases in Thailand, this cross-sectional study compared the performance of a fecal parasite concentrator kit (FPCK) against the Kato–Katz (KK) method for diagnosing intestinal parasites in endemic populations across the Northeast and Southern regions. Methods: Stool samples were collected from 140 participants and examined for intestinal parasitic infections using both FPCK and KK methods. Results: The FPCK method demonstrated a significantly higher detection rate of 45.0% compared to 35.0% for the KK method. For detecting liver fluke (Opisthorchis viverrini), the FPCK method detected significantly more cases than the KK method (10.71% vs. 4.29%) (p = 0.0027). For other parasites such as Trichuris trichiura, Strongyloides stercoralis, and Entamoeba coli, the FPCK method tended to detect more infections, but the differences were not statistically significant (p > 0.05). Conclusions: The FPCK method showed better performance than the KK method for detecting intestinal helminth infections in stool samples, particularly O. viverrini, T. trichiura, S. stercoralis, and Entamoeba coli. Therefore, FPCK could be used as a suitable stool examination method for surveillance and monitoring of preventive treatment for opisthorchiasis.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050117

Authors: Chumpol Anamnart Nawanwat Tepkidakarn

Meningovascular syphilis, a type of neurosyphilis, causes stroke and various types of myelopathy. In recent years, there has been an increase in the incidence of neurosyphilis. However, diagnosing neurosyphilis remains challenging due to the reliance on serum and cerebrospinal fluid (CSF) testing, which has low specificity and sensitivity. Magnetic resonance vessel wall imaging (MR-VWI), recently developed to identify vessel wall pathologies, may aid in diagnosing neurosyphilis. In this cross-sectional study, we performed systematic screening for syphilis in all 366 patients with acute ischemic stroke or transient ischemic attack admitted to our stroke unit. Further CSF analysis and MR-VWI were specifically conducted only on those with reactive serum venereal disease research laboratory (VDRL) or treponema pallidum particle hemagglutination assay (TPHA) tests to evaluate neurosyphilis. Serum screening was reactive in 5.7% (21/366) of patients; among these, the prevalence of likely neurosyphilis (defined by abnormal CSF pleocytosis or protein levels) was 2.2% (8/366). Within this group of eight patients, MR-VWI was technically feasible and thus performed in six cases. Although all CSF-VDRL tests were non-reactive, MR-VWI identified diagnostic evidence of meningovascular syphilis (concentric wall thickening and enhancement) in 33.3% (2/6) of symptomatic patients who underwent the scan. Neurosyphilis remains a critical, treatable cause of stroke that can affect older patients with established vascular risk factors. Our findings demonstrate that routine serum screening is essential, as traditional CSF-VDRL tests may yield false-negative results. MR-VWI serves as a valuable adjunct tool to provide objective evidence of active vasculitis, guiding the initiation of appropriate antibiotic therapy when laboratory results are inconclusive.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050116

Authors: Tri Pudy Asmarawati Fikri Sasongko Widyatama Hari Basuki Notobroto Erwin Astha Triyono Nasronudin Nasronudin Motoyuki Sugai Kuntaman Kuntaman

Background/Objectives: Escherichia coli bacteremia is a major cause of morbidity, mortality, and healthcare expenditure. The increasing prevalence of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E. coli) complicates management and resource utilization. This study aimed to identify clinical predictors of higher hospital costs in E. coli bacteremia. Methods: We conducted a cross-sectional study of hospitalized patients with E. coli bacteremia in Surabaya, Indonesia (2022–2024). Hospital costs were categorized into bed costs, diagnostic costs, pharmacy costs, antibiotic costs, total costs, and daily costs. Costs were compared between ESBL and non-ESBL cases. Predictors of higher hospital costs were analyzed using generalized linear models with a Gamma distribution and log-link. Results: Among 209 patients, 131 (62.7%) had ESBL-producing E. coli. ESBL E. coli bacteremia was associated with significantly higher bed, diagnostic, pharmacy, total, and daily hospital costs than non-ESBL cases, while antibiotic costs were similar. ESBL E. coli bacteremia was associated with higher diagnostic and daily costs. High-care/ICU stay was the strongest predictor of increased costs. Pneumonia and infection source influenced cost components. Longer hospitalization increased total cost but reduced daily cost. Conclusions: Hospital costs in Escherichia coli bacteremia are driven by antimicrobial resistance, disease severity, and healthcare utilization. Targeted strategies such as antimicrobial stewardship and optimized critical care use are essential to reduce the economic burden.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050115

Authors: Amanda Zanatta Berticcelli Andréa Lúcia Corso Pâmela Panassol Leticia Petersen Schmidt Rosito Roberta Rahal de Albuquerque Letícia de Paula e Souza Milena Lessa da Silva Sady Selaimen da Costa Luciana Friedrich

Background: Among the complications caused directly or indirectly by the Human Immunodeficiency Virus (HIV) are alterations in the auditory system. Children who are HIV-exposed but uninfected (HEU) appear to have a higher risk of hearing loss (HL) compared to their unexposed peers, but a lower risk than those infected with HIV. However, the literature remains inconclusive regarding this association. This study aims to evaluate the hearing function of HEU infants during the first months of life and to correlate these findings with maternal, gestational, and neonatal variables. Methods: This prospective cohort study included all HIV-exposed infants born in a quaternary hospital in southern Brazil between 2021 and 2023. Maternal, gestational, and neonatal data were collected, as well as the results of neonatal auditory screening. At approximately 6 months of age, otolaryngological and audiological assessments were performed, including wideband tympanometry and electrophysiological evaluation using Auditory Brainstem Response with frequency-specific stimuli. The prevalence of hearing loss refers to the number of infants affected. Results: Thirty-eight infants, with a mean age of 8 months (±3.3), completed the study. Of these, 1 (2.6%) presented with bilateral sensorineural HL, and 13 (34.2%) presented with conductive HL, with 6 cases being unilateral and 7 bilateral. No associations were found between hearing loss and maternal, gestational, or neonatal variables, except for maternal CD4 count, where higher CD4 cell counts were associated with an increased risk of conductive HL. Conclusion: The findings provide relevant data on auditory alterations in HEU infants, demonstrating a high prevalence of conductive HL. These results highlight the importance of monitoring the hearing of these children during the first years of life.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050114

Authors: Awadh Alanazi Mohamed N. Ibrahim Mohamed A. Elithy

Despite prolonged viral inhibition with combination antiretroviral therapy (ART), HIV-1 survives as genetically intact, replication-capable proviruses within durable CD4+ T-cell fractions, involving central memory, transitional memory, and stem cell-like memory populations, as well as within tissue-resident compartments including lymphoid follicles and gut-associated lymphoid tissue. Reservoir stability is preserved via clonal growth of infected cells and epigenetic processes that impose proviral transcriptional silencing. As a result, current therapeutic approaches seek to either directly alter proviral survival or to improve immune-driven elimination of infected cells. At the molecular level, investigational strategies such as CRISPR–Cas9 and CRISPR–Cas12 gene-editing systems are intended to remove or induce inactivating mutations inside embedded proviral DNA, as well as alter host entrance co-receptors such as CCR5 to provide cellular resistance to infection. In addition, pharmacologic latency regulation is being studied via histone deacetylase inhibitors, protein kinase C agonists, and bromodomain inhibitors to reverse latency, along with Tat inhibitors and other transcriptional repressors aimed to persistently silence proviral expression. Moreover, immunological techniques aim to counteract inefficient endogenous antiviral defenses. Broadly neutralizing antibodies with tailored Fc-driven effector functions are under examination for both neutralization and antibody-dependent cellular cytotoxicity. Therapeutic vaccine approaches seek to elevate polyfunctional HIV-specific CD8+ T-cell responses, while adoptive cellular approaches, involving CAR-T cells aiming HIV envelope epitopes, remain in early clinical research. Immune checkpoint blockade is also being investigated to reverse T-cell depletion inside reservoir-rich tissues. Nevertheless, the key obstacles continue to be the diverse reservoir composition, restricted tissue penetration, viral escape, and safety limitations. The molecular and translational obstacles that characterize attempts toward an HIV cure must be addressed through ongoing multidisciplinary research.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050113

Authors: Zichao Cao Yunan Gu Guoming Li Changsheng Deng

Malaria is one of the major global public health issues. An estimated 282 million malaria cases occurred worldwide in 2024, and the overall prevention and control progress has stagnated or even reversed in some regions. Mass drug administration (MDA), as a potential strategy to accelerate malaria elimination, has regained attention. This paper reviews the evidence base, controversial focuses, and application strategies of MDA in malaria prevention and control. It aims to promote its scientific application in the elimination phase. MDA plays an important role in malaria prevention and control. However, this strategy is accompanied by core limitations such as long-term drug resistance risks, insufficient implementation sustainability, and a high failure rate of regional adaptation. It also faces challenges from multiple common malaria species, as well as the newly discovered Plasmodium knowlesi. We therefore propose an “MDA+” collaborative strategy integrating vaccines, digital monitoring, and cross-border cooperation, so as to optimize resource allocation, achieve full coverage control over various malaria parasites, and advance the global malaria elimination process.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050112

Authors: Rosa Nicole Freiberger Cynthia Alicia Marcela López María Belén Palma Cintia Cevallos Franco Agustin Sviercz Patricio Jarmoluk Marcela Nilda García Jorge Quarleri M. Victoria Delpino

The most common complication of active brucellosis in humans is osteoarticular injury. In the bone marrow microenvironment, mesenchymal stem cells (MSCs) can differentiate into either adipocytes or osteoblasts, and this balance is tightly regulated because an increase in adipogenesis may negatively affect bone formation and favor bone loss. The differentiation of MSCs into adipocytes or osteoblasts is tightly regulated by mechanisms that promote cell fate toward one lineage while repressing the other. Our study demonstrated that Brucella abortus infects MSCs but does not affect the deposition of organic and mineral matrix during osteoblast differentiation. However, the infection upregulates Receptor Activator of Nuclear Factor Kappa-B Ligand (RANKL) expression in osteoblasts, which may contribute to osteoclast activation and bone resorption. Conversely, B. abortus infection significantly influences adipocyte differentiation by modulating lipolysis, lipogenesis, and interactions between lipid droplets and mitochondria. This leads to increased cellular cholesterol levels and reduced intracellular triglycerides, accompanied by glycerol release. These changes result in more differentiated adipocytes and larger lipid droplets. Consequently, we observed increased IL-6 secretion and a higher leptin/adiponectin ratio. Importantly, these effects were independent of a functional type IV secretion system (T4SS), as purified Brucella DNA fully reproduced the adipogenic phenotype. Moreover, inhibition of TLR9—the primary sensor of bacterial DNA—significantly reduced the DNA-induced adipogenic response, demonstrating that adipocyte modulation is at least in part mediated through TLR9 signaling. In summary, B. abortus promotes MSC differentiation toward an inflammatory adipocyte phenotype. It involves a TLR-9-mediated DNA detection. It may contribute to osteoarticular injury and infection-associated bone resorption.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050111

Authors: Paulina Garzaro Carmen Castillo Natalie Fahsen Lucas Santos Joyce Lu Christiana Hug Matthew Lozier Douglas R. Call Celia Cordón-Rosales Brooke M. Ramay

Introduction: Healthcare-associated infections are a significant public health challenge, particularly in resource-limited settings. While hand hygiene is critical for infection prevention, contaminated water from hand hygiene stations (HHSs) in healthcare facilities (HCFs) may undermine infection control efforts. Chlorination can reduce microbial contamination in HHSs, ensuring that water intended for hygiene does not become an infection source. Methods: Water quality was monitored before and after the installation of on-site chlorine dispensers (CDs) in water tanks and HHSs of HCFs in Quetzaltenango, Guatemala, to evaluate their effectiveness in improving water quality. Focus groups were conducted to develop action plan proposals to ensure the intervention’s sustainability. Results: Before the intervention, 75% of HHS water samples tested positive for total coliforms, with 50% testing positive for presumptive extended-spectrum beta-lactamase (ESBL)-producing total coliforms, while 20% were E. coli-positive, with 50% presumptive ESBL-producing E. coli. After installing CD, 1% of samples were coliform-positive over a six-month period. Focus groups identified resource limitations and political barriers and proposed solutions such as developing operational manuals, strengthening inter-institutional relationships, and forming alliances with external organizations. Conclusion: Localized chlorination was successfully implemented using a community participatory approach to improve water quality in resource-limited HCFs. These findings have important implications for infection prevention and control.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11050110

Authors: Gianluca D’Amico Carmen Costache Calin Gherman Ioana Cristina Ilea Adriana Györke

Furuncular myiasis is rarely reported in Southeast/Eastern Europe and may be underrecognized or misdiagnosed in non-endemic settings. We described two imported furuncular myiasis cases diagnosed in Romania following travel to Peru and confirmed the etiologic agent by larval morphology and mitochondrial cytochrome c oxidase subunit I (COI) sequencing. We also conducted a narrative review of published case reports/series from Southeast/Eastern Europe (1900–2025) and summarized case characteristics. A previously healthy 31-year-old woman and 32-year-old man presented with painful furuncle-like lesions on the upper back near the shoulder and the posterolateral upper arm, respectively, associated with pruritus and a sensation of movement. Each lesion had a central punctum with intermittent air bubbles. Occlusion of the breathing pore with petroleum jelly facilitated mechanical extraction of one barrel-shaped larva per lesion. Microscopy showed features consistent with second-instar Dermatobia hominis larvae, and COI sequencing demonstrated 97.14–99.33% identity with reference D. hominis sequences. Literature review identified 25 travel-associated cases, with D. hominis involved mostly after travel to Central/South America. These cases highlight the value of travel history and key diagnostic clues for D. hominis myiasis in travelers that may enable timely diagnosis and minimally invasive management. Greater awareness and reporting are needed to better define epidemiology.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11040109

Authors: Mohamed Haidy Massa Mohamed Aly Ould Lemrabott Osman Abdillahi Guedi Nicolas Gomez Sébastien Briolant Ali Ould Mohamed Salem Boukhary

Aedes aegypti, the main urban vector of dengue fever, poses a major public health problem in Nouakchott, Mauritania. This study analyzed the host-seeking and sugar-feeding behaviors of Ae. aegypti. Mosquitoes were collected using a vacuum cleaner in four districts between December 2023 and October 2024. Biting activity on humans was studied in May 2024, exclusively in the districts of Ksar, Tevragh Zeina and Arafat, between 5:00 a.m. and 9:00 p.m. A negative binomial model was performed to analyze the effect of location and time on the human biting rate (HBR) of mosquitoes. In Nouakchott, except in the Arafat district, Ae. aegypti bites occur mainly outdoors, between 8:00 a.m. and 1:00 p.m., with a peak between 11:00 a.m. and noon (HBR = 20 bites/person), and between 5:00 p.m. and 7:00 p.m., with a peak between 6:00 p.m. and 7:00 p.m. (HBR = 11 bites/person). Inside homes, Ae. aegypti biting activity remains low everywhere (HBR ≤ 1.5 bites/person/hour). Molecular analysis of the origin of the blood meals showed that the females collected in Nouakchott were exclusively anthropophilic. Molecular analysis of the sugar sources revealed a great diversity with sweet potato being among the most common. These results highlight the need for targeted outdoor interventions and larval control measures to reduce the risk of dengue transmission in Nouakchott.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11040108

Authors: Fouad Ibrahim Alshehri Dhaifullah Ahmed Alkhosafi Essam Abdullah Al Asmari Abdulrahman Bin Saeed Anas Mohammed Zarbah Saeed Ali Algarni Mohammed Gasim Ahmed Marim Abdallah Mohamed Fatma Anter Mady Saleh Mohammed Zafer Albakri Ramy Mohamed Ghazy

Background: Saudi Arabia has made significant progress toward malaria elimination; however, imported cases continue to occur, particularly in the southwestern regions. This study aimed to describe the clinical characteristics and outcomes of patients with malaria in the Aseer Region, Saudi Arabia. Methods: A retrospective observational study was conducted at Khamis Mushait General Hospital, Aseer Region, Saudi Arabia, including all patients with malaria from January 2022 to December 2025. Demographic, clinical, laboratory, and outcome data were extracted from the electronic medical records. Severe malaria was defined according to the World Health Organization criteria. Multivariate logistic regression using Firth’s penalized maximum likelihood estimation was performed to identify independent predictors of severe malaria (≥1 WHO criterion). Statistical analysis was performed using R software (version 4.2.1). Results: A total of 311 patients were included, predominantly male (90.0%), with a mean age of 28.8 ± 11.3 years. Ethiopian nationals comprised nearly half the cases (48.2%), followed by Saudi (16.4%) and Yemeni (15.1%) nationals. Plasmodium vivax was the most common species (51.1%), followed by Plasmodium. falciparum (40.2%). Fever was the most frequent symptom (89.4%), followed by fatigue (50.8%), chills (46.9%), and vomiting (39.5%). Low parasitemia (<1%) was the most frequent finding (33.8%), followed by moderate (27.3%) and mild (18.3%) levels, while high (4.2%) and very high parasitemia (1.9%) were uncommon. Severe malaria (≥1 criterion) was diagnosed at 43.7%, with severe anemia (26.0%) and jaundice (23.2%) being the most frequent WHO severity criteria. Notably, 84% of the cases occurred during 2024–2025, indicating a recent outbreak, with a sharp peak of 43 cases in October 2024. Multivariate logistic regression identified two independent predictors of having at least one WHO severity criterion: higher parasitemia level (adjusted OR = 1.70 per 1% increase, 95% CI: 1.40–2.11, p < 0.001) and non-Saudi nationality (adjusted OR = 2.40, 95% CI: 1.10–5.62, p = 0.027). Conclusions: Malaria in the Aseer Region predominantly affects young adult male expatriates, suggesting its imported nature. The predominance of P. vivax represents a shift from historical patterns. Parasitemia level and being of non-Saudi nationality independently predict severe malaria and may therefore support risk stratification and clinical decision-making. The dramatic case surge in 2024–2025 highlights regional vulnerability to outbreaks despite control progress. These findings support enhanced screening for at-risk populations, maintenance of clinical capacity for severe malaria management, and robust surveillance systems for early outbreak detection.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11040107

Authors: Cansel Askin Behcet Al Cihad Unsal Karahaliloglu Yunus Emre Gemici Ibrahim Coban Abdulkerim Emre Yanar

Background: Rabies remains a major zoonotic disease worldwide, particularly in regions with large populations of free-roaming animals. In urban settings, animal-related injuries constitute a substantial healthcare burden and frequently result in the administration of rabies post-exposure prophylaxis (PEP). This study aimed to evaluate the epidemiological characteristics of animal exposures and real-world PEP practices in a metropolitan emergency department. Methods: This retrospective descriptive study included 1960 patients presenting to a tertiary metropolitan emergency department between 1 March and 1 September 2025 with suspected animal exposure. Demographic data, animal species involved, exposure mechanisms, animal ownership and vaccination status, time to presentation, and PEP practices were analyzed using descriptive statistics. Results: Most exposures were cat-related (86.3%) and were caused by scratching (81.5%). Nearly all injuries were superficial (99.8%), while deep injuries were rare (0.2%). The majority of animals were classified as strays (90.1%), and vaccination status was unknown in 81.2% of cases. Rabies immunoglobulin was administered to only 0.6% of patients; however, rabies vaccination was initiated in 98.8% of patients. Approximately 74.5% of patients presented within 24 h. Post-exposure animal observation was documented in only 20.2% of cases. Conclusions: Urban animal exposures in this metropolitan setting were predominantly superficial and cat-related, yet nearly all patients received rabies vaccination. Limited animal observation and incomplete vaccination documentation appear to constrain risk stratification and may contribute to the use of precautionary PEP. Strengthening surveillance systems, improving documentation, and implementing evidence-based risk-stratification strategies are essential for optimizing rabies prophylaxis practices in urban environments.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11040106

Authors: Josephine Abrazaldo Patrick de Vera Sheila Grace Martin John Leo Dayrit Daryl Christian Mejos Ferdinand Mortel

Neglected tropical diseases (NTDs) such as soil-transmitted helminthiasis, lymphatic filariasis, schistosomiasis, leprosy, rabies, and food-borne trematodiasis are endemic in the Philippines. Despite global and national elimination efforts, these six NTDs remain a persistent burden to the poor, those living in Geographically Isolated and Disadvantaged Areas (GIDAs), and other vulnerable groups. This narrative review synthesized data from Field Health Services Information System (FHSIS) reports of the Philippine Department of Health (DOH) from 2020 to 2024, the available literature from electronic databases, and DOH and WHO reports focusing on the challenges, barriers, and gaps in NTD control and elimination in the country. Core challenges include complex epidemiological landscapes, lapses in disease surveillance, infrastructure, and fragmented health care systems. Gaps include access to diagnostics, insufficient funding and human resource training, and scarcity of local studies focusing on endemic NTDs. With these challenges and gaps, this review highlights the need for a real-time feedback loop system in surveillance strategy, community-based interventions, full integration of NTDs in primary health care, and collaboration between government, NGOs and private entities. Addressing these challenges and gaps is key to shifting from control to elimination.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11040105

Authors: Jérôme Munyangi wa Nkola Pierre Akilimali Zalagile Hendrick Lukuke Mbutshu Spartacus Kabala Munyemo Imani Ramazani Bin Eradi Alioune Camara

Background: The Democratic Republic of the Congo accounts for approximately 12–13% of the global malaria burden. While international guidelines oppose the use of Artemisia annua infusions due to risks of sub-therapeutic dosing and resistance selection, the plant remains widely used in resource-limited regions. This study evaluates the clinical acceptability and perceptions of healthcare providers regarding the integration of Artemisia annua tea into formal malaria control in the Maniema province. Methods: A cross-sectional survey was conducted among 337 healthcare professionals in the Kalima health district using the KoboCollect digital platform. Multivariate logistic regression was employed to identify the primary socio-professional determinants of clinical acceptability. Results: The overall clinical acceptability of Artemisia annua integration was 81.0%, with 82.8% of providers perceiving the preparation as effective. Rural residency was the strongest predictor of adherence (AOR = 6.847; p = 0.003), reflecting a pragmatic response to frequent ACT stockouts and high treatment costs. Despite high acceptability, 49.0% of providers identified the lack of clinical evidence as a major barrier, and 91.4% demanded formal training on standardized dosage and biological mechanisms. Conclusions: A significant “policy–practice gap” exists between international guidelines and field realities in the DRC. Healthcare providers demonstrate high readiness for integration but emphasize the absolute necessity of galenic standardization to mitigate resistance risks. To address these concerns, a complementary genomic investigation is currently underway in the same study area, comparing PfKelch13 mutation prevalence among Artemisia tea users versus ACT-treated patients. This molecular surveillance will provide essential evidence to define safety parameters for future phytopharmaceutical integration.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11040104

Authors: Cherotich Jesca Tangus Ndichu Maingi James Chege Nganga Davis Karanja Njuguna Kariuki Njaanake Bruno Enagnon Lokonon Gloria Ivy Mensah Kennedy Kwasi Addo Andrée Prisca Ndjoug Ndour Bassirou Bonfoh

Toxoplasmosis is a widely distributed zoonosis caused by the protozoan parasite Toxoplasma gondii. Infection during pregnancy is a major public health concern due to its potential impact on both maternal health and fetal development. Early detection of maternal infection is critical to prevent adverse outcomes; however, maternal signs are often subtle, non-specific or absent, complicating timely diagnosis. This scoping review aimed to map and synthesise existing evidence on early maternal signs, pregnancy and foetal outcomes, frequently assessed risk factors, and diagnostic approaches of toxoplasmosis in expectant mothers in Africa. The review was done in accordance with the PRISMA-ScR guidelines. A literature search of PubMed, Scopus, ResearchGate, and Google Scholar was performed to identify studies published between 2000 and 2025. Retrieved records were managed using Zotero (version 8.0.4) for deduplication and screening. Only English-language studies conducted in Africa and reporting relevant maternal or clinical data were included. A total of 28 cross-sectional studies were included. Lymphadenopathy (25.0%) was the most frequently reported maternal early sign, followed by flu-like illness, asymptomatic infection, low-grade or mild fever, and fatigue or malaise (each 10.7%). Congenital anomalies (50.0%) and miscarriage or spontaneous abortion (42.9%) were the most commonly reported foetal and pregnancy outcomes. Frequently reported risk factors were exposure to cat faeces (57.1%) and ingestion of undercooked or raw meat (42.9%). Diagnostic approaches were commonly enzyme-based immunoassays (78.6%), with limited use of RDTs and molecular methods. These findings suggest the need for improved early detection and prevention strategies in high-risk, low-resource African settings. Enhancing routine screening, health education, and access to appropriate diagnostics are considered. Future studies should consider adopting standardised reporting and integrating sensitive, affordable, rapid diagnostic approaches to enhance early detection and reduce the burden of congenital toxoplasmosis.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11040103

Authors: Shuai Wei Xinyan Chen Shangkun Cai Xiaoqin Li Ting Lu Yaoting Li Yuanlin Hou Yanwen Li Yunliang Shi

Background: Cysteine proteases of Clonorchis sinensis are potential diagnostic antigens, yet the performance of individual members within this diverse enzyme family requires systematic evaluation. This study aimed to assess the diagnostic potential of four recombinant cysteine proteases (rCsCP1–4) for human clonorchiasis. Methods: An indirect ELISA was developed to measure serum reactivity (IgG, IgG subclasses, IgA) against rCsCP1–4. The assay was validated using 180 microscopy-confirmed positive and 148 negative control sera. Samples were randomly split into training and validation sets (7.5:2.5). Diagnostic performance of single antigens and their combinations was evaluated using univariate and multivariate logistic regression and compared with a commercial kit. Key metrics included the area under the curve (AUC), sensitivity, specificity, accuracy, F1-score, and Kappa coefficient. Results: Four single antigen–antibody pairs showed high performance: rCsCP1-IgG4 (AUC = 0.928), rCsCP2-IgA (AUC = 0.863), rCsCP3-IgG1 (AUC = 0.920), and rCsCP4-IgG4 (AUC = 0.958). Among these, rCsCP1-IgG4, rCsCP3-IgG1, and rCsCP4-IgG4 outperformed the commercial kit, achieving higher sensitivity (92.0%, 96.0%, 96.0% vs. 86.0%), specificity (87.5%, 81.3%, 90.6% vs. 78.1%), accuracy (92.0%, 88.9%, 94.1% vs. 86.0%), and F1-scores (0.902, 0.902, 0.939 vs. 0.829). The Kappa values for rCsCP1-IgG4 (0.768) and rCsCP4-IgG4 (0.773) indicated substantial agreement with the microscopic standard. Multi-antigen combinations (triple or quadruple) further enhanced performance, achieving sensitivity and specificity > 98% with an AUC approaching 1.0. Conclusions: This study identifies rCsCP1 and rCsCP4, particularly in combination with IgG4 detection, as highly promising diagnostic targets for clonorchiasis. Multi-antigen combinations significantly improved diagnostic performance compared to single-antigen assays, offering a strategy for high-precision diagnosis. Furthermore, the efficacy of the rCsCP2-IgA pair suggests that detecting fecal secretory IgA could be a novel avenue for non-invasive, self-testing applications.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11040102

Authors: Yazdan Mirzanejad

As we conclude this set of ten publications in Tropical Medicine and Infectious Disease, three clear themes emerge to the surface [...]

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11040100

Authors: Ivy Rukasha Kabelo Gabriel Kaapu

Background: Drug-resistant tuberculosis (DR-TB) continues to pose a major challenge in Limpopo Province, a predominantly rural region of South Africa with high prevalence of HIV and mobility of the cross-border population. Despite the scale-up of short all-oral bedaquiline-based regimens, there is limited recent provincial evidence describing DR-TB epidemiological characteristics and treatment outcomes in the post-COVID-19 period. This study aimed to assess resistance patterns, treatment outcomes, and factors associated with unfavorable outcomes among patients with DR-TB in Limpopo Province from 2020 to 2024. Methods: A retrospective cohort study was conducted using routinely collected data from the Electronic Drug Resistant Tuberculosis Register (EDRWeb). All laboratory-confirmed DR-TB cases diagnosed between January 2020 and December 2024 were included. Descriptive statistics were used to summarize demographic and clinical characteristics. Multivariable logistic regression was performed to identify predictors of unfavorable outcomes (treatment failure, death, and loss to follow-up). Kaplan–Meier survival analysis was used to estimate survival probability following treatment initiation. Results: A total of 1240 DR-TB cases were recorded, of which 1165 (94%) had documented treatment outcomes. Rifampicin-resistant TB (RR-TB) predominated throughout the study period, accounting for 76% (951/1240) of cases and remaining stable over time. Treatment success improved from 173/260 (67%) in 2020 to 130/166 (78%) in 2024, while loss to follow-up declined from 34/260 (13%) to 4/166 (2%). Kaplan–Meier survival analysis showed that mortality occurred predominantly during the early phase of treatment. Patients receiving bedaquiline-containing regimens demonstrated significantly higher survival probability compared with those not receiving bedaquiline (log-rank p = 0.024; HR 0.58, 95% CI: 0.35–0.94). In multivariable analysis, HIV infection was independently associated with unfavorable outcomes (aOR 1.36; 95% CI: 1.04–1.77; p = 0.025), while increasing age showed a modest association with poorer outcomes. Conclusions: Treatment outcomes for DR-TB improved over the study period, accompanied by declining loss to follow-up and improved survival. The survival advantage observed among patients receiving bedaquiline-containing regimens supports continued prioritization of bedaquiline-based treatment strategies in DR-TB management. Strengthening access to these regimens, alongside integrated HIV care, may further improve treatment outcomes in Limpopo Province and similar high-burden settings in South Africa.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11040101

Authors: Asanka R. DeZoysa Madeline Kwan Lekshmi K. Edison Rebecca Barber Lisa Glick Thomas Denagamage Subhashinie Kariyawasam

Uropathogenic Escherichia coli (UPEC) is a leading cause of urinary tract infections (UTIs) in companion animals. This study characterized 42 UPEC isolates recovered from dogs and cats at the University of Florida, College of Veterinary Medicine Diagnostic Laboratories between 2023 and 2024, focusing on antimicrobial resistance (AMR), virulence gene profiles, biofilm-forming ability, and phylogroup distribution of the isolates. Antimicrobial susceptibility testing (AST) showed that 40.48% of the isolates were resistant to at least one of the tested antibiotics, and 9.52% exhibited multidrug resistance (MDR). Phylogroup B2 was predominant (69.05%), and 61.90% of isolates demonstrated strong biofilm formation in artificial human urine. Virulence gene analysis revealed the presence of genes mediating adhesion (fim, pap, sfa), iron acquisition (fyuA, iro), biofilm formation (csg, bcs, pga, ycg/ymg), motility (fli, mot, flh), and stress response (oxyR, soxR/S, kat). Multiple plasmids carrying AMR and virulence determinants were also identified. The co-occurrence of the traits underscores the potential for persistent and recurrent infections, which can complicate therapeutic outcomes and facilitate horizontal gene transfer (HGT). The detection of antimicrobial-resistant, highly virulent UPEC strains possessing human UPEC traits in companion animals suggests the risk of zoonotic and reverse-zoonotic transmission, particularly in households with close pet–owner interactions. These findings emphasize the importance of judicious antimicrobial use, routine molecular surveillance, and integrated One Health strategies to mitigate the veterinary and public health threats associated with UPEC infections in companion animals.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11040099

Authors: Ngoan Tran Le Ngan Dieu Thi Ta Quyet Quang Nguyen Thanh C. Bui Joshua T. Mattila Suresh V. Kuchipudi Toan Ha

Tuberculosis (TB) remains a major public health burden in Vietnam, yet few studies have examined pulmonary TB mortality trends at sub-national levels, where local epidemiological patterns may differ substantially from national averages and reveal high-risk populations requiring targeted interventions and inform resource allocation. Lang Son, Vietnam, is a mountainous border province with many ethnic minority residents, and extensive cross-border movement creates distinct challenges for TB surveillance and treatment adherence. Although mortality has declined in line with national trends, rates in this border province remain higher than those in Vietnam’s major urban centers. This disparity suggests a hidden burden where Lang Son’s unique geographic challenges and ethnic diversity create health inequities that are often obscured by favorable national-level averages. To better understand local epidemiological patterns, this study examined temporal trends and gender differences in pulmonary TB mortality in Lang Son Province over a 12-year period (2005–2008 and 2011–2018). Using data from a population-based mortality registration system, we calculated crude and age-standardized mortality rates (ASR) per 100,000 person-years. Temporal trends were assessed using Poisson regression. The overall ASR was 7.7 per 100,000 person-years among men (95% CI: 6.5–9.0) and 1.9 among women (95% CI: 1.3–2.7), yielding a male-to-female ASR ratio of 4.1. The age-standardized pulmonary TB mortality declined by approximately 49.2% (from 6.3 (95% CI: 4.1–9.2) to 3.2 (95% CI: 1.9–4.9) per 100,000 person-years; p = 0.025). Notably, 69.9% of deaths occurred in individuals under age 70. While declines were observed in both sexes, sex-specific temporal trends were not statistically significant (p > 0.05). Despite these improvements, persistently higher mortality among men and older adults highlights ongoing inequities in TB outcomes within the province. These pre-pandemic findings provide an essential epidemiological baseline for assessing COVID-19’s impact on TB control and underscore the need for age- and gender-targeted interventions at sub-national levels to accelerate Vietnam’s progress toward TB elimination.

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed11040098

Authors: Andrea Romero-Magaña Carlos Chacón-Díaz Alejandro Alfaro-Alarcón Marcela Suárez-Esquivel Esteban Chaves-Olarte Gabriela Hernández-Mora Edgardo Moreno Elías Barquero-Calvo

Members of the genus Brucella are bacterial pathogens of global importance, and their increasing detection in marine mammals has raised concerns for wildlife conservation and public health. In this study, we evaluated the biological and pathogenic characteristics of two Brucella sp. sequence type 27 (ST27) isolates obtained from a dwarf sperm whale (Kogia sima). We compared them with terrestrial and marine Brucella reference strains. We assessed resistance to polymyxin B and human serum complement, intracellular infection dynamics in HeLa epithelial cells, persistence in a murine model, and associated hematological and histopathological changes, and analyzed lipopolysaccharide (LPS) profiles. The Kogia isolates exhibited resistance to polymyxin B and serum complement, comparable to that of B. abortus 2308W and marine mammal Brucella strains. In HeLa cells, the isolates displayed distinct, strain-specific intracellular infection dynamics. In the murine model, both isolates persisted in the spleen and induced granulomatous lesions. However, splenic bacterial loads and histopathological scores were generally lower than those observed with B. abortus 2308W, which exhibited the highest virulence among the strains evaluated. Hematological alterations associated with Kogia isolates were also less pronounced than those induced by B. abortus 2308W, indicating an intermediate and strain-dependent virulence phenotype without evidence of enhanced virulence relative to the terrestrial reference strain. Western blot analyses showed that Brucella sp. ST27 isolates were not recognized by anti-B. abortus or anti-O-antigen monoclonal antibodies, while exhibiting a distinct recognition pattern with anti-B. canis serum, indicating differences in surface antigen composition. Comparative whole-genome analysis identified a limited number of isolate-specific variants affecting coding and intergenic regions. Collectively, these findings highlight phenotypic and genetic features of Brucella sp. ST27 from Kogia sima, which distinguishes it from other marine and terrestrial Brucella strains and supports further investigation into its biological behavior and potential public health relevance.