Tropical Medicine and Infectious Disease

Background: The availability of laboratory tests to screen and diagnose migrants and travellers for neglected and tropical parasitic diseases significantly impacts individual and public health. Italian scientific societies for parasitology, tropical diseases, and global health developed a survey to assess number and geographical localisation of laboratories able to carry out adequate diagnostics. Methods: An open-ended and multiple-choice questionnaire was constructed and sent to 752 members working in Italian microbiology laboratories via scientific societies’ mailing lists. Data concerning malaria, cystic echinococcosis, leishmaniasis, schistosomiasis, strongyloidiasis, and Chagas disease were included. Results: Members from 96 laboratories replied. At least one laboratory responded from 18 out of 20 Italian regions. Serological tests for Schistosoma spp., Strongyloides stercoralis, Trypanosoma cruzi, Echinococcus spp., and Leishmania spp. are performed in <50% of responding laboratories. Only 56.6% of labs provide all three recommended tests for malaria diagnosis in the emergency room. Direct identification methods availability varies for Schistosoma eggs (75–95.8%), S. stercoralis larvae (53.1%), trypomastigotes (59.4%), and Leishmania amastigotes (53.1%). Geographical differences (mainly northern versus southern regions) were evident. Conclusions: The survey underlines the need to improve diagnosis for neglected and tropical diseases, to define a network of reference laboratories for testing less prevalent diseases, and to share information, education, and training for both clinicians and microbiologists/parasitologists. Full article

Influenza poses a significant global health burden due to its high transmissibility, antigenic variability, and substantial morbidity. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has further complicated influenza dynamics, highlighting the need for rapid, accurate, and accessible diagnostics. This review comprehensively summarized the advancements in influenza virus (IFV) detection, from conventional methods like viral culture and serology to modern molecular techniques, including CRISPR-based systems, next-generation sequencing (NGS), and biosensors. We analyze the sensitivity, specificity, and applicability of these methods and emphasize their roles in clinical and public health settings. While traditional techniques remain valuable for strain characterization, novel technologies like CRISPR and portable biosensors offer rapid, low-resource solutions. This review provides a comprehensive insight into the development of integrated diagnostic strategies for seasonal IFV epidemics and future pandemics. Full article

Scrub typhus is an acute febrile vector-borne infectious disease caused by Orientia tsutsugamushi (O. tsutsugamushi) and transmitted through the bite of infected chigger mite larvae. Transmission involves complex ecological interactions among vectors, hosts, and environmental factors. Accumulating evidence indicates complex interactions between the scrub typhus incidence and multilevel environmental determinants, encompassing meteorological factors (e.g., temperature, humidity, precipitation, wind speed, sunshine duration, and atmospheric pressure), geographical conditions (e.g., topography, elevation, and landcover), and socioeconomic factors (e.g., economic level, cultural practices, residential conditions, and human behaviors). However, significant discrepancies persist among studies regarding the effect sizes and temporal associations, and the precise mechanisms remain incompletely elucidated. This review synthesizes the evidence on environment–disease relationships, clarifies the methodological inconsistencies, analyzes the potential sources of heterogeneity, and highlights the critical knowledge gaps to inform targeted prevention and control strategies and guide future research priorities. Full article

Tennessee’s ecological diversity, spanning forests, farmland, and urban areas, provides an ideal foundation for applying the One Health approach, which integrates human, animal, and environmental health. This review examines Tennessee’s current One Health landscape, highlighting active initiatives, ongoing challenges, and future directions. Key efforts involve workforce development, disease surveillance, outbreak response, environmental conservation, and public education, led by a coalition of state agencies, universities, and the Tennessee One Health Committee. These programs promote cross-sector collaboration to address issues such as zoonotic diseases, climate change, land use shifts, and environmental contaminants. Notably, climate-driven changes, including rising temperatures and altered species distributions, pose increasing threats to health and ecological stability. Tennessee has responded with targeted monitoring programs and climate partnerships. Education is also a priority, with the growing integration of One Health into K–12 and higher education to build a transdisciplinary workforce. However, the state faces barriers, including limited funding for the One Health workforce, undefined workforce roles, and informal inter-agency data sharing. Despite these obstacles, Tennessee’s successful responses to outbreaks like avian influenza and rabies demonstrate the power of coordinated action. To strengthen its One Health strategy, the state must expand funding, formalize roles, improve data systems, and enhance biodiversity and climate resilience efforts positioning itself as a national leader in interdisciplinary collaborative solutions. Full article

Studies have indicated that there was a disease interaction of pandemic influenza with respiratory tuberculosis (TB) in Malta, which could explain the heightened mortality recorded in young adults. We revisit the 1918/19 influenza and TB syndemic potential on the island of Malta. Borrowing from crisis studies that explore the harvesting effect, we used the method of assessing changes in pre-pandemic, pandemic, fallow, and post-pandemic mortality/life expectancy to reveal the syndemic experience. Pre-pandemic (1914–1917) life expectancy at birth was significantly higher, at 37.91 years, than during the pandemic (1918), when life expectancy dropped to 33.26 years (Z = 10.56, p < 0.0001). Post-pandemic (1919) life expectancy rose to 43.49 years, which was an even longer life expectancy than pre-pandemic (Z = 17.61, p < 0.0001). There were significant changes in TB mortality death rates during the four periods in those of reproductive age. Augmenting our framework for studies of syndemics involving short-term events, we proposed the identification of contributing, driving, and limiting factors. Underlying living conditions contributed to the syndemic. The exacerbation of housing conditions, the economy associated with the First World War, and meteorological measures—temperature, relative humidity, and rainfall—were driving factors. The early implementation of mitigation strategies, such as restrictions on mass gatherings, were limiting factors of the syndemic. Full article

Bacillus Calmette–Guérin (BCG)-related immune reconstitution inflammatory syndrome (IRIS) is a recognised complication following antiretroviral therapy (ART) initiation in HIV-infected infants. We report the case of a 19-month-old child with undiagnosed perinatally acquired HIV due to maternal nondisclosure. The child developed ipsilateral axillary lymphadenitis at the BCG vaccination site shortly after starting ART. The clinical features and temporal association with ART supported a diagnosis of BCG-IRIS. The child was successfully managed with conservative pharmacological treatment alone—rifampicin, isoniazid, and macrolide therapy—without surgical incision or corticosteroids. Progressive improvement of the lesion was observed, and complete clinical resolution occurred over the following months, alongside immune recovery. This case underscores the importance of recognising BCG-IRIS, even in settings where HIV diagnosis may be delayed, and supports the feasibility of conservative management in paediatric patients, potentially avoiding surgical intervention in settings of localised disease. Full article

Aedes aegypti, the main urban vector of dengue fever, represents a growing public health problem in Nouakchott, the capital of Mauritania. Identifying the factors influencing the distribution and productivity of its breeding sites is essential for the development of effective control strategies. From May 2023 to April 2024, physico-chemical characteristics were recorded and mosquito larvae were collected, using a standard dipping method, from 60 water collections each month during the dry season and twice a month during the rainy season, totaling 294 observations. The larval positivity of water collections and larval abundance of breeding sites over the time were modeled using a random-effect logistic regression model and a negative binomial regression model, respectively. The depth, distance from habitat, type of water collection and exposure to sunlight were statistically significant and independently associated with water collection positivity for Ae. aegypti larvae (aOR = 5.18, 95%CI [1.66–16.18], p-value = 0.005; aOR = 0.00, 95%CI [0.00–0.02], p-value < 0.001; aOR = 252.88, 95%CI [4.05–15,786.84], p-value = 0.009 and aOR = 0.04, 95%CI [0.01–0.26], p-value < 0.001, respectively). Aedes aegypti larval habitats were mainly artificial (90%), temporary (n = 217 observations), close to dwellings (n = 114) and shaded (n = 96). Plastic water tanks (n = 17, 48.6%), wells (n = 6, 17.1%) and barrels (n = 4, 11.4%) were the most common breeding sites. Larval abundance was negatively associated with containers of increasing pH and surface area (aOR = 0.50, 95%CI [0.33–0.75] p-value = 0.001 and aOR = 0.48, 95%CI [0.27–0.87], p-value = 0.016, respectively). As Ae. aegypti mosquitoes are multi-resistant to adult insecticides and dengue has become endemo-epidemic since 2014, vector control should give the priority to the physical removal or treatment of shaded, peridomestic containers—particularly plastic water tanks and barrels—and consider the use of biological larvicides to target breeding sites with low pH and small surface areas. Full article

Studies on the burden of COVID-19 cases in Colombia have focused on specific populations and short timeframes. A retrospective observational study was conducted on adult patients aged 18 diagnosed with COVID-19 who received inpatient and/or outpatient medical care at a large health maintenance organization, to evaluate the burden of COVID-19 cases in Colombia (from March 2020 to January 2023) and associations with demographic and clinical characteristics. COVID-19 cases were identified with ICD-10 codes and confirmed by a laboratory test. The statistical analysis focused on descriptors of the frequency of events. A multivariate regression model was used to identify factors associated with severe conditions and death. Of the 953,661 cases detected, most cases (~79%) were mild or moderate (handled as outpatients). There were 20.1% (N = 191,260) severe cases and 0.9% (N = 8841) critical cases. Most COVID patients were unvaccinated (94.6%) and had, on average, one comorbidity. Hypertension (19.1%), immunocompromised condition (23.8%), mental health conditions (15%), obesity (10.8%), and cancer (11.2%) were the common prevalent comorbidities. The presence of comorbidity increased the risk of severe or critical COVID-19. COVID-19 cases were associated with the lack of vaccination and comorbidities. Effective vaccination strategies are needed to reduce the burden of COVID-19 in Colombia and, considering budgetary constraints, it is advisable to prioritize the elderly or populations with underlying conditions. Full article

A male in his 60s presented with a four-month history of dysuria and lower urinary tract symptoms (LUTS). He had a history of elevated PSA and benign prostatic hyperplasia (BPH), previously treated with transurethral resection of the prostate (TURP). Multiparametric MRI (MP-MRI) revealed a PI-RADS 5 lesion, raising suspicion of malignancy. However, histopathological analysis from MRI fusion-targeted biopsies confirmed tuberculous prostatitis. The patient was treated with antituberculosis drugs, resulting in symptomatic improvement and a significant PSA decline. This case highlights the diagnostic challenge of distinguishing tuberculous prostatitis from prostate cancer, particularly in tuberculosis-endemic regions. Our literature review reveals that patients with tuberculous prostatitis undergoing MRI are at least 50 years old, originate from endemic areas, and exhibit PI-RADS scores ranging from 2 to 5, indicating inter-rater variability. Histopathological confirmation remains essential in cases with ambiguous imaging and clinical findings. Full article

Strongyloidiasis is a common intestinal infection that may persist in humans for decades without symptoms or can present as a potentially fatal, broadly disseminated infection in an immunocompromised host. This report describes a rare case of concomitant strongyloidiasis and E. coli meningitis that was successfully recognized and treated in a patient 20 years post-renal transplantation. Full article

Parasitic diseases represent a severe global burden, with current treatments often limited by toxicity, drug resistance, and suboptimal efficacy in chronic infections. This review examines the emerging role of triazole-based compounds, originally developed as antifungals, in advanced antiparasitic therapy. Their unique structural properties, particularly those of 1,2,3- and 1,2,4-triazole isomers, facilitate diverse binding interactions and favorable pharmacokinetics. By leveraging innovative synthetic approaches, such as click chemistry (copper-catalyzed azide–alkyne cycloaddition) and structure-based design, researchers have repurposed and optimized triazole scaffolds to target essential parasite pathways, including sterol biosynthesis via CYP51 and other novel enzymatic routes. Preclinical studies in models of Chagas disease, leishmaniasis, malaria, and helminth infections demonstrate that derivatives like posaconazole, ravuconazole, and DSM265 exhibit potent in vitro and in vivo activity, although their primarily static effects have limited their success as monotherapies in chronic cases. Combination strategies and hybrid molecules have demonstrated the potential to enhance efficacy and mitigate drug resistance. Despite challenges in achieving complete parasite clearance and managing potential toxicity, interdisciplinary efforts across medicinal chemistry, parasitology, and clinical research highlight the significant potential of triazoles as components of next-generation, patient-friendly antiparasitic regimens. These findings support the further optimization and clinical evaluation of triazole-based agents to improve treatments for neglected parasitic diseases. Full article

Healthcare workers (HCWs) face an increased risk of tuberculosis (TB) due to occupational exposure. This study aimed to estimate the point prevalence of TB infection (TBI) from the initial test performed, while the reversion and conversion were done by subsequent testing at one year among HCWs in Puducherry, India. A prospective cohort study was conducted among a sample of proportionately chosen HCWs based on their occupational strata of a tertiary hospital in 2022. TBI was assessed using IGRA (4th generation QuantiFeron—TB gold plus kits) after TB symptom screening. The IGRA test was repeated at the end of one year. Reversion was defined as a positive IGRA test at the baseline and had values < 0.2 IU/L in TB1 or TB2 tubes during follow-up. Conversion was defined as a negative IGRA result at the baseline and had values of >0.7 IU/L in TB1 or TB2 tubes during follow-up. Of the 400 HCWs included, the mean (SD) age was 37 (7) years. Median (IQR) work experience was 15.7 (10–21) years. TBI was seen in 150 HCWs (37.7%, 95% CI: 33.0–42.7), and one had active TB. A total of 128/150 HCWs with TBI at baseline were followed up, and 15 had TBI reversion (11.7 per 100 person-years; 95% CI: 6.7–18.5). Thirteen HCWs (5.6 per 100 person-years; 95% CI: 3.3–9.8) had TBI conversion. Full article

Oncomelania hupensis quadrasi is the intermediate host of S. japonicum, the causative species of schistosomiasis in the Philippines. Conventionally, risk areas are identified by procedures requiring highly skilled personnel and constant surveillance efforts. Recent developments in disease diagnostics explore the utilization of environmental DNA as targets for polymerase chain reactions in disease surveillance. In this study, a low-cost, specific, and efficient SYBR Green-based real-time PCR assay to detect O. h. quadrasi DNA from water samples was developed, optimized, and validated. Primers were designed based on the A18 microsatellite region of O. h. quadrasi. The assay exhibited a detection limit of one copy number per microliter at 99.4% efficiency and R² = 0.999, which specifically amplified O. h. quadrasi DNA only. Validation of this assay in environmental water samples demonstrated 100% PPV and NPV values, suggesting its potential as a tool for identifying risk areas, pathogen-directed surveillance, policy making, and disease control. Full article

Background: We aimed to describe trends in M. genitalium prevalence and associated resistance in Canada between 1980 and 2022. Methods: Ecological study and a scoping review. We collected publicly available data published by the governments of all Canadian provinces and territories. We also systematically searched PubMed, Medline, Embase, and grey literature using the keywords ‘M. genitalium’, ‘Canada’, and all provinces and territories. We reported M. genitalium prevalence, age, sex, gender, symptoms, coinfections, sample types used for diagnosis, and macrolide and fluoroquinolone resistance rates. Results: National or provincial surveillance systems for M. genitalium are absent. Eight studies reported the epidemiology of M. genitalium. The prevalence ranged between 3% in Quebec and 30.3% in Ontario. Half of the patients reported symptoms. The most collected sample for M. genitalium diagnosis was urine, followed by cervical and urethral swabs. Co-infection with Chlamydia trachomatis was reported in 3.3% to 16.4% of cases and with Neisseria gonorrhoeae in 0.0% to 24.0%. Macrolide resistance ranged between 25% and 82.1%, and fluoroquinolone resistance between 0.0% and 29.1%. Conclusions: M. genitalium prevalence and resistance rates varied by sex, gender, province, and specimen type. In the absence of routine surveillance, incomplete data hinders understanding the bacterium’s natural history, its impact on some key groups, and the tracking of antibiotic resistance. Full article

Background: Recent setbacks in malaria control in Comoros demand a reassessment of its evolving epidemiology. Methods: Using the Global Burden of Disease (GBD) Study 2021 data, we analyzed malaria trends from 2010 to 2021, stratified by sex. We quantified the contributions of demographic and epidemiological factors to these trends and identified risk factors for malaria-related disability-adjusted life years (DALYs). Results: From 2010 to 2021, malaria cases, deaths, and DALYs in Comoros fell by −90.22%, −94.44%, and −94.88%; and the corresponding age-standardized rates declined with EAPCs of −18.70% (95% CI: −33.77 to −0.20), −23.89% (95% CI: −36.58 to −8.66), and −24.49% (95% CI: −36.88 to −9.66), with steeper declines in males. Nevertheless, all indicators increased in 2018 and again in 2021. In sub-Saharan Africa, only cases increased, while other metrics declined slightly. In Comoros, incidence shifted mainly to adults ≥25 years, unlike sub-Saharan Africa, where children < 5 years were most affected. Population growth drove increases in cases, deaths and DALYs, whereas epidemiological shifts had the opposite effect. Child underweight was the leading risk factor for malaria DALYs. Conclusions: Existing interventions can achieve malaria control in Comoros; however, rebounds in 2018 and 2021 highlight the need to identify and address drivers of resurgence. Full article

The iCARE Nigeria study is evaluating a daily text message medication reminder intervention (TXTXT) to improve viral suppression and medication adherence among youth living with HIV (YLH), aged 15–24 years. In this sub-study, we evaluated text message responsiveness (text-back) at 24 weeks of the intervention as an indicator of engagement, as well as barriers and facilitators at one of six clinical study sites. Differences in responses by age group, birth sex, schooling status, education, mode of infection, and weekend/weekday and holiday/non-holiday periods were analyzed using t-test and multiple linear regression. Focus group discussions were conducted among three groups (low, average, and high text message responsiveness) and analyzed using a rapid content analysis approach. Overall, TXTXT responsiveness was 26.5% (4606/17,367); older age (18–24 years) and weekdays (versus weekends) were significantly associated with higher responsiveness. Facilitators included being comfortable receiving personalized text messages. Barriers included a lack of airtime and messages received late. Overall, text-back responsiveness to daily medication adherence messages among YLH was low, better among older participants, and higher on weekdays. Addressing barriers and promoting facilitators may improve responsiveness. Full article

Visceral leishmaniasis (VL) is a severe parasitic disease caused by Leishmania spp., with a significant impact on pediatric populations, particularly in endemic regions. The diagnosis of VL in children requires a high index of suspicion, as clinical manifestations—such as prolonged fever, hepatosplenomegaly, and pancytopenia—overlap with other infectious and hematologic diseases. While serological and molecular tests aid in detection, bone marrow aspiration remains the gold standard for definitive diagnosis. In this case series, we describe five pediatric patients diagnosed with VL in Italy, emphasizing the importance of a timely and accurate diagnostic approach. Liposomal amphotericin B (LAmB) is the first-line treatment in Southern Europe due to its high efficacy and reduced toxicity. Our patients received a standard regimen of 3 mg/kg daily for five days, plus an additional dose on day 10, leading to rapid clinical improvement. However, some cases required supportive care, such as red blood cell transfusions, particularly in patients with co-infections. Despite being a neglected disease, VL is re-emerging in Europe, influenced by climate change, increased pet ownership, and migration from endemic regions. Prevention strategies focus on vector control, canine vaccination, and public health awareness. The global rise in pediatric VL highlights the need for improved surveillance, access to affordable treatments, and the development of effective vaccines to mitigate the disease burden in both endemic and non-endemic areas. Full article

Scabies and tungiasis are skin-related neglected tropical diseases (NTDs) associated with poverty and poor living conditions. We performed an ecological study covering a state in northeast Brazil to identify socio-economic and environmental factors associated with the occurrence of severe scabies and severe tungiasis, respectively. Data on disease occurrence on the municipality level were derived from a previous study based on online questionnaires. A total of 47 (26.0%) of the 181 state’s municipalities reported severe tungiasis, and 113 (62.4%) severe scabies. Municipalities with occurrence of severe tungiasis were characterized by higher annual rainfalls (median = 883 mm vs. 741 mm; p = 0.037), higher minimum temperatures (median = 23.4 °C vs. 22.7 °C; p = 0.002), higher aridity indices indicating more humid climates (median = 45.1 vs. 50.6; p = 0.019), lower altitudes (median = 88.8 m vs. 201 m; p < 0.001), higher mean air humidity (66.5% vs. 63%; p = 0.018), and better socioeconomic indices (Municipal Human Development Index [MHDI]—median = 0.616 vs. 0.611; p = 0.048/MHDI Longevity—mean = 0.769 vs. 0.759; p = 0.007/Municipal Development Index [MDI]—median = 27.5 vs. 21.8; p < 0.001). Municipalities with predominant luvisol soil characteristics had a lower risk for severe tungiasis (RR = 0.46; 95% CI = 0.27–0.79; p = 0.003), whereas municipalities with predominant gleysols had a significantly higher risk (RR = 2.44; 95% CI = 1.43–4.15; p = 0.010). Municipalities with occurrence of severe scabies were characterized by significantly higher annual rainfalls (median = 804 mm vs. 708 mm; p = 0.001), higher minimum temperatures (23.1 °C vs. 22.3 °C; p < 0.001), higher aridity index (median = 48.2 vs. 41.9; p = 0.014), higher air humidity (65.9% vs. 61%; p = 0.001), lower altitudes (median = 153 m vs. 246 m; p = 0.003), and better socio-economic indicators (MHDI—median = 0.616 vs. 608; p= 0.012/MHDI Education—mean = 0.559 vs. 0.541; p = 0.014/MDI—median = 24.3 vs. 21.1; p = 0.005). In multivariate regression analysis, MDI remained significantly associated with the presence of severe tungiasis in the final model (RR = 1.04; 95% CI: 1.02–1.05; p < 0.001) and the presence of severe scabies with minimum temperature (RR = 1.13; 95% CI: 1.04–1.24; p = 0.003) and aridity index (RR = 1.01; 95% CI: 1.00–1.01; p = 0.004). Our study underscores the importance of environmental and socioeconomic factors for the occurrence of severe scabies and tungiasis in a semi-arid climatic context, offering a perspective for identification of high-risk areas, and providing evidence for the control of skin NTDs withina One Health approach. Full article