Tropical Medicine and Infectious Disease

18 pages, 2816 KiB

Open AccessArticle

“I-We-I”: Visualizing Adolescents’ Perceptions and Apprehension to Transition to Adult HIV Care at a Supportive Transition Facility in the Cape Town Metropole, South Africa

by Charné Petinger, Brian van Wyk and Talitha Crowley

Trop. Med. Infect. Dis. 2025, 10(5), 126; https://doi.org/10.3390/tropicalmed10050126 - 6 May 2025

Abstract

Adolescents living with HIV (ALHIV) (10–19 years) make up approximately 4.2% (320,000) of people living with HIV in South Africa. Adolescence is a developmental period characterized by pervasive biological, social and psychological changes, which challenges adherence and retention in care for ALHIV on [...] Read more.

Adolescents living with HIV (ALHIV) (10–19 years) make up approximately 4.2% (320,000) of people living with HIV in South Africa. Adolescence is a developmental period characterized by pervasive biological, social and psychological changes, which challenges adherence and retention in care for ALHIV on antiretroviral therapy (ART). Further, as ALHIV grow “older”, they are expected to transition to the adult HIV treatment programme, where they should assume greater responsibility for managing their chronic condition and healthcare pathway. Whereas it is imperative that ALHIV are transitioned when they are ready, little is known about the challenges and experiences of ALHIV before and during transition. The aim of this paper was to report on the experiences and challenges of transition for ALHIV who received ART at an adolescent-friendly service that is adjunct to a public primary healthcare facility in the Western Cape province of South Africa. Methods: Photovoice methods were employed to explore the transition experiences of ALHIV on ART at a “supportive transition” public health facility in the Cape Town Metro in South Africa. Participants took pictures that depict their experience pre- and during transition to adult care and discussed these in groups with peers. Audio data were digitally recorded and transcribed verbatim and subjected to thematic analysis using Atlas.Ti version 24. Results: The emergent themes described their apprehension to transitioning to adult care; self-management; challenges to adherence; the need for psychosocial support; and how adolescent-friendly services were filling the gap. Conclusions: We illuminate the “I-We-I” configuration, to reflect (the first “I”) individual ALHIV experiences as isolated before being transferred to the supportive facility; how they experience a sense of belonging and family (“we”) in the supportive facility; but face apprehension about transitioning to adult care in the local clinic, where they have to self-manage (final “I”). Full article

(This article belongs to the Special Issue Adolescent HIV Care and Transition Strategies: Challenges, Outcomes, and Interventions)

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13 pages, 1974 KiB

Open AccessReview

Navigating the Parasitic Landscape: Insights into Infection Patterns and Public Health Strategies in West Africa

by Patrick F. Ayeh-Kumi, Patience B. Tetteh-Quarcoo, Isabella N. A. Aryee, Peter Nii Apai Baddoo, James Teye Ocansey and Michael Kofi Otoboah

Trop. Med. Infect. Dis. 2025, 10(5), 125; https://doi.org/10.3390/tropicalmed10050125 - 6 May 2025

Abstract

Parasitic infections remain a significant public health challenge in West Africa, contributing to high morbidity and mortality rates, economic burdens, and healthcare system strain. Malaria, soil-transmitted helminths, schistosomiasis, and other parasitic diseases persist due to environmental, socio-economic, and healthcare barriers. A systematic literature [...] Read more.

Parasitic infections remain a significant public health challenge in West Africa, contributing to high morbidity and mortality rates, economic burdens, and healthcare system strain. Malaria, soil-transmitted helminths, schistosomiasis, and other parasitic diseases persist due to environmental, socio-economic, and healthcare barriers. A systematic literature search was conducted using databases such as PubMed, Scopus, Web of Science, and Science Direct. Studies published between 2014 and 2024 were screened using predefined eligibility criteria. Cross-sectional and case–control studies reporting on prevalence, diagnostic techniques, and treatment of parasitic infections in West Africa were included. The Rayyan online platform was used for screening, and data extraction focused on study location, prevalence rates, diagnostic methods, and treatment regimens. This review identified the high prevalence rates of malaria, schistosomiasis, and soil-transmitted helminths across various West African countries. Co-infections were frequently reported, particularly among children and pregnant women. Diagnostic methods ranged from traditional microscopy to advanced molecular techniques, though accessibility remained a challenge in resource-limited settings. Treatment strategies, including artemisinin-based combination therapies for malaria and mass drug administration for helminths, showed varying efficacy due to reinfection risks and emerging drug resistance. Factors influencing transmission included environmental conditions, sanitation practices, socio-economic status, and healthcare access. Parasitic infections in West Africa continue to pose significant health and economic challenges. Integrated control programs, enhanced surveillance systems, improved access to diagnostics and treatment, and targeted public health interventions are essential for reducing disease burden. Further research is needed to evaluate the long-term impact of existing interventions and explore innovative solutions for parasite control and elimination. Full article

(This article belongs to the Special Issue Advances in Parasitic Neglected Tropical Diseases)

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16 pages, 685 KiB

Open AccessArticle

Factors Associated with Prolonged Mechanical Ventilation and 30-Day Mortality in Intubated COVID-19 Patients with Invasive Fungal Infections: A Retrospective Observational Study

by Hung Manh Than, Thang Van Dao, Truong Van Cao, Tuyen Van Duong, Thach Ngoc Pham, Cap Trung Nguyen, Phu Dinh Vu, Nam Van Le, Binh Nhu Do, Phuong Viet Nguyen, Ha Nhi Vu and Duong Minh Vu

Trop. Med. Infect. Dis. 2025, 10(5), 124; https://doi.org/10.3390/tropicalmed10050124 - 6 May 2025

Abstract

COVID-19-associated invasive fungal infections (CAIFIs) contribute to increased mortality and morbidity rates. This study explores the epidemiology, laboratory parameters, radiological characteristics, treatments, and 30-day mortality risks of CAIFI in critically ill intubated patients while also evaluating factors associated with prolonged mechanical ventilation (PMV) [...] Read more.

COVID-19-associated invasive fungal infections (CAIFIs) contribute to increased mortality and morbidity rates. This study explores the epidemiology, laboratory parameters, radiological characteristics, treatments, and 30-day mortality risks of CAIFI in critically ill intubated patients while also evaluating factors associated with prolonged mechanical ventilation (PMV) in this population. Adults admitted to a tertiary hospital from 1 April 2021 to 31 March 2022 who were diagnosed with severe COVID-19, required invasive mechanical ventilation, and developed invasive fungal infection (IFI) during hospitalization were analyzed in this retrospective cohort study. Among 150 patients, 65 (43.3%) required PMV, with an in-hospital mortality rate of 64%. Candida albicans (47%) and Aspergillus fumigatus (27%) were the most prevalent pathogens. Multivariate analysis revealed that COVID-19 vaccination (adjusted odds ratio, aOR = 0.155, 95% confidence interval, 95% CI = 0.029–0.835, p = 0.030) and higher serum protein levels (aOR = 0.900, 95% CI = 0.819–0.989, p = 0.028) were significantly associated with a reduced risk of PMV. Meanwhile, elevated glucose levels (hazard ratio, HR = 1.047, 95% CI = 1.003–1.093, p = 0.036) and an increased neutrophil-to-lymphocyte ratio (HR = 1.024, 95% CI = 1.009–1.039, p = 0.002) were correlated with a greater 30-day mortality risk. Tracheostomy emerged as a protective factor, significantly reducing the risk of 30-day mortality (HR = 0.273, 95% CI = 0.127–0.589, p = 0.001). In this single-center study, patients with CAIFI exhibit a high mortality rate. Clinicians should maintain vigilance for IFI in critically ill COVID-19 patients with mechanical ventilation. Full article

(This article belongs to the Special Issue Monitoring and Diagnosis of Invasive Fungal Infections)

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46 pages, 15851 KiB

Open AccessArticle

Emerging Human Fascioliasis in India: Review of Case Reports, Climate Change Impact, and Geo-Historical Correlation Defining Areas and Seasons of High Infection Risk

by Santiago Mas-Coma, Pablo F. Cuervo, Purna Bahadur Chetri, Timir Tripathi, Albis Francesco Gabrielli and M. Dolores Bargues

Trop. Med. Infect. Dis. 2025, 10(5), 123; https://doi.org/10.3390/tropicalmed10050123 - 2 May 2025

Abstract

The trematodes Fasciola hepatica and F. gigantica are transmitted by lymnaeid snails and cause fascioliasis in livestock and humans. Human infection is emerging in southern and southeastern Asia. In India, the number of case reports has increased since 1993. This multidisciplinary study analyzes [...] Read more.

The trematodes Fasciola hepatica and F. gigantica are transmitted by lymnaeid snails and cause fascioliasis in livestock and humans. Human infection is emerging in southern and southeastern Asia. In India, the number of case reports has increased since 1993. This multidisciplinary study analyzes the epidemiological scenario of human infection. The study reviews the total of 55 fascioliasis patients, their characteristics, and geographical distribution. Causes underlying this emergence are assessed by analyzing (i) the climate change suffered by India based on 40-year-data from meteorological stations, and (ii) the geographical fascioliasis hotspots according to archeological–historical records about thousands of years of pack animal movements. The review suggests frequent misdiagnosis of the wide lowland-distributed F. gigantica with F. hepatica and emphasizes the need to obtain anamnesic information about the locality of residence and the infection source. Prevalence appears to be higher in females and in the 30–40-year age group. The time elapsed between symptom onset and diagnosis varied from 10 days to 5 years (mean 9.2 months). Infection was diagnosed by egg finding (in 12 cases), adult finding (28), serology (3), and clinics and image techniques (12). Climate diagrams and the Wb-bs forecast index show higher temperatures favoring the warm condition-preferring main snail vector Radix luteola and a precipitation increase due to fewer rainy days but more days of extreme rainfall, leading to increasing surface water availability and favoring fascioliasis transmission. Climate trends indicate a risk of future increasing fascioliasis emergence, including a seasonal infection risk from June–July to October–November. Geographical zones of high human infection risk defined by archeological–historical analyses concern: (i) the Indo-Gangetic Plains and corridors used by the old Grand Trunk Road and Daksinapatha Road, (ii) northern mountainous areas by connections with the Silk Road and Tea-Horse Road, and (iii) the hinterlands of western and eastern seaport cities involved in the past Maritime Silk Road. Routes and nodes are illustrated, all transhumant–nomadic–pastoralist groups are detailed, and livestock prevalences per state are given. A baseline defining areas and seasons of high infection risk is established for the first time in India. This is henceforth expected to be helpful for physicians, prevention measures, control initiatives, and recommendations for health administration officers. Full article

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13 pages, 5923 KiB

Open AccessArticle

Biological and Molecular Characterization of Five Trypanosoma cruzi (Chagas, 1909) (Kinetoplastida, Trypanosomatidae) Isolates from the State of Hidalgo, Mexico

by Yessenia Montes-Vergara, Alberto Antonio-Campos, José Miguel Padilla-Valdez, Erick Abraham Contreras-López, Julio Cesar Noguez-García, Nancy Rivas and Ricardo Alejandre-Aguilar

Trop. Med. Infect. Dis. 2025, 10(5), 122; https://doi.org/10.3390/tropicalmed10050122 - 1 May 2025

Abstract

Trypanosoma cruzi, the causal agent of Chagas disease, exhibits great genetic diversity, which has been related to its biological properties. However, these are poorly known in strains from the endemic area of Hidalgo. To assess the parasite’s virulence, we evaluated parasitemia, mortality, [...] Read more.

Trypanosoma cruzi, the causal agent of Chagas disease, exhibits great genetic diversity, which has been related to its biological properties. However, these are poorly known in strains from the endemic area of Hidalgo. To assess the parasite’s virulence, we evaluated parasitemia, mortality, and tropism in thirteen organs of CD1 mice during the acute phase of infection. For genotyping, we amplified the mini-exon gene from T. cruzi DNA using PCR. All five isolates were identified as belonging to DTU TcI. The peak of parasitemia occurred between 25 and 29 days post-infection. The Tultitlán and Olma isolates did not cause any mouse deaths, whereas Ixcatépec produced 100% mortality. Mice infected with the Barrio Hondo isolate exhibited the highest parasitemia, while those infected with Cuatecomaco had the lowest. The five isolates generated varying degrees of infection and chronic inflammation; only two isolates triggered acute pancreatitis and myocarditis. No amastigote nests were found in the hearts of mice infected with the Ixcatépec isolate. Our findings suggest that the damage caused by T. cruzi strains from Hidalgo may extend beyond cardiac lesions in the acute phase of Chagas disease regardless of their classification as TcI and variability in parasitemia levels. Full article

(This article belongs to the Topic Vector-Borne Disease Spatial Epidemiology, Disease Ecology, and Zoonoses)

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13 pages, 1235 KiB

Open AccessArticle

Validation of a Real-Time PCR for the Diagnosis of Leishmania Species Using the Hsp20 Gene

by Mayra Maldonado-Aroni, Nyshon Rojas-Palomino, Aide Sandoval-Juarez, Marco Galarza-Pérez, José Alarcón-Guerrero, Rosa Guevara-Montero and Víctor Cárdenas-López

Trop. Med. Infect. Dis. 2025, 10(5), 121; https://doi.org/10.3390/tropicalmed10050121 - 1 May 2025

Abstract

Leishmaniasis is a complex neglected tropical disease that impacts public health, particularly in resource-limited populations where access to accurate and timely diagnosis is often limited. Current diagnostic methods, primarily relying on microscopy, suffer from low sensitivity and specificity, hindering effective case management and [...] Read more.

Leishmaniasis is a complex neglected tropical disease that impacts public health, particularly in resource-limited populations where access to accurate and timely diagnosis is often limited. Current diagnostic methods, primarily relying on microscopy, suffer from low sensitivity and specificity, hindering effective case management and disease control. The objective of this study was to validate a novel real-time PCR assay targeting the conserved Hsp20 gene for the detection of Leishmania spp. We evaluated the performance of the method using two distinct detection systems, such as SYBR Green and TaqMan probes, against a diverse panel of 225 clinical samples confirmed to have the disease. The real-time PCR targeting Hsp20 using SYBR Green demonstrated a sensitivity of 88% (95% CI: 83.53–92.47) and 100% specificity. Meanwhile, the TaqMan probe demonstrated a lower sensitivity of 47% (95% CI: 29.53–64.92). The high sensitivity and robust performance of the real-time PCR using SYBR Green establish its potential as a valuable diagnostic tool, particularly useful in endemic regions where rapid and accurate diagnosis is critical for timely treatment and effective disease control. Full article

(This article belongs to the Special Issue Molecular Surveillance and New Diagnostic Tests for Leishmaniasis)

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10 pages, 614 KiB

Open AccessReview

An Outbreak of Multidrug-Resistant Shigella flexneri Serotype 2a Among People Experiencing Homelessness in Vancouver

by Victor Leung, Gordon Ritchie, Aleksandra Stefanovic, Colin Lee, Sam Chorlton, Nancy Matic, Marc G. Romney, Althea Hayden and Christopher F. Lowe

Trop. Med. Infect. Dis. 2025, 10(5), 120; https://doi.org/10.3390/tropicalmed10050120 - 28 Apr 2025

Abstract

Background: We describe a community-based outbreak of multidrug-resistant Shigella flexneri serotype 2a among people experiencing homelessness (PEH) in Vancouver’s Downtown Eastside during the COVID-19 pandemic. Methods: In this observational cohort study, we followed the Outbreak Reports and Intervention Studies of Nosocomial [...] Read more.

Background: We describe a community-based outbreak of multidrug-resistant Shigella flexneri serotype 2a among people experiencing homelessness (PEH) in Vancouver’s Downtown Eastside during the COVID-19 pandemic. Methods: In this observational cohort study, we followed the Outbreak Reports and Intervention Studies of Nosocomial Infection (ORION) reporting guidelines. We identified cases by laboratory surveillance and collected demographic and clinical data from the medical charts or patient interviews. We implemented enhanced surveillance and disseminated testing and management guidelines. Shigella flexneri isolates were serotyped, and whole-genome sequencing was performed. Results: We identified 101 confirmed cases of Shigella flexneri 2a (80% male; median age 43) between 31 January and 16 December 2021. All the affected individuals experienced homelessness, and substance use disorder was the most common comorbidity (88%). Five patients required ICU hospitalization, and one death occurred within 30 days. Core-genome multilocus sequence typing analysis confirmed a clonal outbreak. All S. flexneri isolates were phenotypically and genotypically multidrug-resistant. Conclusions: COVID-19 exacerbated longstanding public health concerns around the dearth of hygiene and sanitation resources available to PEH. Preventing similar outbreaks will require addressing these risks and finding solutions to the crisis of homelessness in Canada. Full article

(This article belongs to the Special Issue Emerging Trends of Infectious Diseases in Canada)

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12 pages, 2630 KiB

Open AccessArticle

Evaluation of Ground and Aerial Ultra-Low Volume Applications Using ReMoa Tri Against Deltamethrin-Resistant Aedes aegypti from Collier County, Florida

by Decyo McDuffie, Sara Kacinskas, Suzanne Li, Casey Parker-Crockett and Keira J. Lucas

Trop. Med. Infect. Dis. 2025, 10(5), 119; https://doi.org/10.3390/tropicalmed10050119 - 26 Apr 2025

Abstract

New intervention methods and product formulations are needed to better control pyrethroid-resistant Aedes aegypti populations and mitigate the risk of mosquito-borne disease. ReMoa Tri is a novel adulticidal space spray that utilizes a different mode of action than the commonly used adulticides: pyrethroids [...] Read more.

New intervention methods and product formulations are needed to better control pyrethroid-resistant Aedes aegypti populations and mitigate the risk of mosquito-borne disease. ReMoa Tri is a novel adulticidal space spray that utilizes a different mode of action than the commonly used adulticides: pyrethroids and organophosphates. As a triple-action space spray, ReMoa Tri combines three components: Fenpropathrin, a mixed-type I/II pyrethroid; abamectin, a macrocyclic lactone; and C8910, a patented fatty acid chain. Prior studies performed by Collier Mosquito Control District showed that ReMoa Tri is effective at controlling type I pyrethroid-resistant Ae. aegypti mosquitoes. To further validate these results and the performance of ReMoa Tri, we conducted a semi-field evaluation using ground and aerial ULV (ultra-low volume) applications with field-caught deltamethrin-resistant Ae. aegypti and a susceptible Ae. aegypti laboratory strain. Ground evaluations tested ReMoa Tri and a type II pyrethroid-based product, DeltaGard. While ReMoa Tri was equally effective against Collier’s deltamethrin-resistant Ae. aegypti and the susceptible laboratory strain, DeltaGard was effective against both strains, with reduced efficacy at farther distances. Similarly, aerial evaluations also showed that ReMoa Tri was equally effective against Collier’s deltamethrin-resistant Ae. aegypti strain and susceptible laboratory strain. This study further confirms ReMoa Tri’s potential as an effective alternative to pyrethroid-based adulticides, both in ground and aerial applications, for managing pyrethroid-resistant Ae. aegypti. Full article

(This article belongs to the Special Issue Mosquito-Borne Diseases: Intervention Strategies Used to Control Mosquito Populations and Reduce Disease Transmission)

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10 pages, 589 KiB

Open AccessArticle

Yellow Fever Virus (YFV) Detection in Different Species of Culicids Collected During an Outbreak in Southeastern Brazil, 2016–2019

by Giovana Santos Caleiro, Lucila Oliveira Vilela, Karolina Morales Barrio Nuevo, Rosa Maria Tubaki, Regiane Maria Tironi de Menezes, Luis Filipe Mucci, Juliana Telles-de-Deus, Eduardo Sterlino Bergo, Emerson Luiz Lima Araújo and Mariana Sequetin Cunha

Trop. Med. Infect. Dis. 2025, 10(5), 118; https://doi.org/10.3390/tropicalmed10050118 - 24 Apr 2025

Abstract

Yellow fever virus (YFV) is an endemic arbovirus in parts of Africa and the Americas. In Brazil, following the eradication of the urban transmission cycle, YFV is maintained in a sylvatic cycle involving several species of neotropical primates and mosquitoes of the genera [...] Read more.

Yellow fever virus (YFV) is an endemic arbovirus in parts of Africa and the Americas. In Brazil, following the eradication of the urban transmission cycle, YFV is maintained in a sylvatic cycle involving several species of neotropical primates and mosquitoes of the genera Haemagogus and Sabethes, which serve as primary and secondary vectors, respectively. During the 2016–2019 outbreak in São Paulo State, a total of 3731 mosquito pools were collected from sites with ongoing epizootic events in 192 municipalities. The RT-qPCR analysis detected YFV in 46 pools (1.4%) across nine mosquito species, including both primary and secondary vectors, as well as species from the genera Aedes and Psorophora. Differences in viral loads were observed among species. While Aedes aegypti was not found to be positive, the detection of natural YFV infection in other Aedes species raises concerns about potential virus reurbanization. Further studies are needed to clarify the role of additional mosquito species in YFV transmission in Brazil. Full article

(This article belongs to the Special Issue Emerging Viral Threats: Surveillance, Impact, and Mitigation)

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18 pages, 6098 KiB

Open AccessArticle

Secondary Metabolites from a New Antibiotic-Producing Endophytic Streptomyces Isolate Inhibited Pathogenic and Multidrug-Resistant Mycobacterium tuberculosis Strains

by Govinda Raju Vadankula, Arshad Rizvi, Haider Ali, Rakhi Khunjamayum, V. V. Ramprasad Eedara, Vijay Nema, Debananda Singh Ningthoujam, Katragadda Suresh Babu, Prakasham Reddy Shetty, Shekhar C. Mande and Sharmistha Banerjee

Trop. Med. Infect. Dis. 2025, 10(5), 117; https://doi.org/10.3390/tropicalmed10050117 - 23 Apr 2025

Abstract

The long regimen of drug therapy, the emergence of drug-resistance (DR), and infections with non-tuberculous mycobacteria (NTMs) are alarming challenges in controlling tuberculosis (TB), a disease caused by Mycobacterium tuberculosis (M.tb), necessitating the pursuit of new, broad-spectrum anti-mycobacterials. With more than [...] Read more.

The long regimen of drug therapy, the emergence of drug-resistance (DR), and infections with non-tuberculous mycobacteria (NTMs) are alarming challenges in controlling tuberculosis (TB), a disease caused by Mycobacterium tuberculosis (M.tb), necessitating the pursuit of new, broad-spectrum anti-mycobacterials. With more than two-thirds of the clinically useful antibiotics originating from the bacterial phylum Actinomycetota, and their enormous diversity in India, we explored atypical environments for new bacterial strains with potential anti-M.tb activity. In this study, we the examined the secondary metabolites of soil and endophytic bacterial isolates from the wetland niches of Manipur, India, and determined their anti-mycobacterial properties using viability assays. The ethyl acetate culture filtrate extracts of one of the isolates, named Streptomyces sp. SbAr007, showed broad-spectrum anti-mycobacterial activity against laboratory M.tb strains H37Ra and H37Rv, a clinical drug-resistant M.tb and non-tuberculous mycobacteria (NTM). The isolate was characterized for its phenotype and genetic identity, which indicated its closeness to Streptomyces samsunensis, Streptomyces malaysiensis, and Streptomyces solisilvae. Further, macrophage infection assays showed that the extracts could effectively control the intracellular mycobacterial growth but had negligible cytotoxicity to PBMCs from healthy donors. LC-MS identified an unusual combination of antibiotics in these culture filtrate extracts, which can be further explored for specific active molecules or as a formulation against DR-TB. Full article

(This article belongs to the Special Issue Biomarkers, Diagnostic, and Therapeutic Approaches for Mycobacterial Diseases)

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14 pages, 1670 KiB

Open AccessArticle

Desiccation Tolerance of Aedes aegypti and Aedes albopictus Eggs of Northeastern Argentina Origin

by Mía E. Martín, Elizabet L. Estallo, Luis G. Estrada, Carolina Matiz Enriquez and Marina Stein

Trop. Med. Infect. Dis. 2025, 10(4), 116; https://doi.org/10.3390/tropicalmed10040116 - 21 Apr 2025

Abstract

This study examines the desiccation tolerance of Aedes aegypti and Aedes albopictus eggs, two major arbovirus vectors, in a subtropical region of Argentina to understand their survival under varying relative humidity (RH) conditions (35%, 68%, and 82%). Laboratory experiments revealed that Ae. aegypti [...] Read more.

This study examines the desiccation tolerance of Aedes aegypti and Aedes albopictus eggs, two major arbovirus vectors, in a subtropical region of Argentina to understand their survival under varying relative humidity (RH) conditions (35%, 68%, and 82%). Laboratory experiments revealed that Ae. aegypti eggs exhibited significantly higher survival rates across all RH levels and exposure times compared to Ae. albopictus. After 1 month, Ae. aegypti eggs maintained 88% survival at 35% RH, while Ae. albopictus survival dropped to 38%. This disparity was more pronounced at low RH, where Ae. albopictus eggs experienced a rapid decline in survival over time. The results highlight the importance of RH as a key factor influencing the persistence of both species in the environment. The coexistence of Ae. aegypti and Ae. albopictus in Puerto Iguazú suggests that microhabitats with distinct humidity conditions may favor one species over the other. These findings provide crucial insights for predicting mosquito population dynamics under changing climate conditions and developing more effective vector control strategies to reduce arbovirus transmission in subtropical regions. Full article

(This article belongs to the Special Issue Mosquito-Borne Diseases: Intervention Strategies Used to Control Mosquito Populations and Reduce Disease Transmission)

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11 pages, 1329 KiB

Open AccessReview

The State of Antimicrobial Resistance of Gram-Negative Bacilli in Canada

by Jeremy Li, Andrew Walkty, Philippe Lagacé-Wiens, James Karlowsky and George Zhanel

Trop. Med. Infect. Dis. 2025, 10(4), 115; https://doi.org/10.3390/tropicalmed10040115 - 21 Apr 2025

Abstract

In the last two decades, there has been an increase in resistance among Gram-negative bacteria in Canada. From 2007 to 2016, the proportion of ESBL-producing isolates among Escherichia coli and Klebsiella pneumoniae isolates increased from 3.5% to 11.1%. There has also been an [...] Read more.

In the last two decades, there has been an increase in resistance among Gram-negative bacteria in Canada. From 2007 to 2016, the proportion of ESBL-producing isolates among Escherichia coli and Klebsiella pneumoniae isolates increased from 3.5% to 11.1%. There has also been an increase in carbapenem use over this time period, which may be contributing to the increasing prevalence of carbapenemase-producing Enterobacterales (CPE) in Canada. CPE, which were historically associated with travel, are now mostly acquired domestically. The prevalence of multi-drug resistant (MDR) Pseudomonas aeruginosa has decreased slightly, possibly due to decreasing use of fluoroquinolones and aminoglycosides. Many of the most effective antimicrobials for the treatment of infections with resistant Gram-negative organisms, including many of the novel β-lactam/β-lactamase inhibitors (βL/βLIs), are not marketed in Canada. A coordinated focus on antimicrobial stewardship and infection control is necessary to slow the spread of resistance and to preserve the efficacy of our current antimicrobials for future generations. Full article

(This article belongs to the Special Issue Emerging Trends of Infectious Diseases in Canada)

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15 pages, 1092 KiB

Open AccessArticle

Qualitative Study of Nutritional Support-Related Perceptions and Preferences Among Persons Affected by TB, Family Caregivers, and Healthcare Providers in India

by Balaji Ramraj, Karikalan Nagarajan, Debjani Ram Purakayastha, Major Madhukar, Makesh Kumar, Neha Raj, Sarath Kumar, Banappa S. Unger, Nithin Rajamani, Sampada Dipak Bangar, Murugesan Periyasamy, Hansraj Choudhary, Yasaswany Santhoshkumar, Ramesh Kumar, Seema Sahay, Nivedita Gupta and Chandrasekaran Padmapriyadarsini

Trop. Med. Infect. Dis. 2025, 10(4), 114; https://doi.org/10.3390/tropicalmed10040114 - 21 Apr 2025

Abstract

Evidence on the implementation aspects of nutritional support interventions for persons with TB in India is limited. This qualitative study employed focus group discussions with persons with TB (n = 71), their family caregivers (n = 17), and healthcare providers (n = 18). [...] Read more.

Evidence on the implementation aspects of nutritional support interventions for persons with TB in India is limited. This qualitative study employed focus group discussions with persons with TB (n = 71), their family caregivers (n = 17), and healthcare providers (n = 18). The study was conducted from August 2023 to April 2024 in five states in India. Participants’ knowledge, perceptions, and practices about nutritional intake, experiences, and expectations when accessing nutritional support were explored. Four nutrition-related themes emerged: (a) the experiences and perceptions of persons with tuberculosis and their caregivers, explained by their understanding of the importance of adequate nutrition and TB cures; (b) changes in food practices, explained by protein food adoption, alongside food insecurity experienced by those in poverty; (c) Direct Benefit Transfer (DBT)-related issues, explained by insufficiency and access-related gaps; and (d) preferred choices for nutrition support delivery, explained by less preference towards the involvement of intermediaries and a public distribution system alongside preference for the provision of nutrition through treatment facilities. Our findings underscore the importance of the provision of protein-rich food and an increase in financial support based on needs assessments. Mitigating the linkage and access gaps in DBT is needed. The delivery of ready-to-consume food through tuberculosis treatment facilities could be prioritized. Full article

(This article belongs to the Special Issue Tuberculosis Control in Africa and Asia)

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19 pages, 9253 KiB

Open AccessSystematic Review

Prevalence of Trichomonas vaginalis Among Women in the Chinese Population: A Systematic Review and Meta-Analysis

by Shuang Li, Jiahui Xu, Sisi Ru, Changjun Hu, Chongyang Liu, Xingquan Sun, Heteng Guo and Xi Zhang

Trop. Med. Infect. Dis. 2025, 10(4), 113; https://doi.org/10.3390/tropicalmed10040113 - 19 Apr 2025

Abstract

Trichomonas vaginalis (TV) is the most common non-viral sexually transmitted infection (STI) among women worldwide. However, there is little information available regarding the burden of trichomoniasis infection among Chinese women. The aim of the present study is to assess the status of trichomoniasis [...] Read more.

Trichomonas vaginalis (TV) is the most common non-viral sexually transmitted infection (STI) among women worldwide. However, there is little information available regarding the burden of trichomoniasis infection among Chinese women. The aim of the present study is to assess the status of trichomoniasis in China. To address this gap, we searched seven databases for relevant studies published from their inception to June 2024. The overall prevalence of T. vaginalis in China was determined to be 6.31% with a high level of heterogeneity (I² = 99.68%). Subgroup analysis also demonstrated a statistically significant association between the T. vaginalis prevalence in the type of population, age range, year, residential status, and province. Among these, sex workers are the most prominent with 12.16%. Meta-regression analysis indicated that the infection rate of T. vaginalis among Chinese women had not shown a significant decline over time (p = 0.2919). Therefore, it continues to be a public health issue that should not be overlooked. Sex workers and rural women have a relatively higher infection rate of trichomoniasis, and this is largely associated with sexual safety awareness and hygiene conditions. Our findings provide crucial information for healthcare authorities and can shed light on the prevention strategies for trichomoniasis in China. Full article

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14 pages, 1531 KiB

Open AccessArticle

Infectivity and Dissemination of Dengue Virus-1 in Different Aedes aegypti Populations Throughout Brazil

by Amanda Cupertino de Freitas, Ellen Santos, Lívia Baldon, Silvana de Mendonça, Fernanda Oliveira Rezende, Rafaela Moreira, Viviane Sousa, Mariana Lima, Emanuele Silva, Flávia Ferreira, João Paulo Pereira de Almeida, Siad Amadou, Bruno Marçal, Sara Comini, Marcele Rocha, Yaovi Todjro, Thiago Jiran Leite, Viviane Santos, Isaque João da Silva de Faria, Marta Giovanetti, Luiz Carlos Junior Alcantara, Luciano A. Moreira and Alvaro Ferreira Show full author list Hide full author list

Trop. Med. Infect. Dis. 2025, 10(4), 112; https://doi.org/10.3390/tropicalmed10040112 - 19 Apr 2025

Abstract

Dengue virus, one of the most prevalent mosquito-borne flaviviruses affecting humans globally, is primarily transmitted by the Aedes aegypti mosquito, which thrives in densely populated urban environments. Dengue incidence has surged in recent decades, becoming a major public health concern in many regions, [...] Read more.

Dengue virus, one of the most prevalent mosquito-borne flaviviruses affecting humans globally, is primarily transmitted by the Aedes aegypti mosquito, which thrives in densely populated urban environments. Dengue incidence has surged in recent decades, becoming a major public health concern in many regions, particularly in Brazil, which has experienced recurrent outbreaks and reported over 6.6 million probable cases in the year of 2024. While the link between the mosquito vector and dengue transmission is well understood, the effects of different DENV types and their interactions with the vector capacity of natural mosquito populations are crucial for understanding disease dynamics. Here we report findings from experiments designed to analyze and compare the infectivity and dissemination of the DENV-1 strain among five Ae. aegypti populations collected from different regions of Brazil. When exposed to DENV-infected AG129 mice for blood feeding, these populations exhibited variations in infection rates and dissemination efficiency. Eight days post-infection, all populations demonstrated high infection rates, underscoring the substantial capacity of Brazilian Ae. aegypti populations to support the locally circulating DENV-1 strain. Our results demonstrate variation in Ae. aegypti vector competence across Brazil, revealing distinct patterns of DENV transmission efficiency. These findings highlight the necessity for geographically tailored control strategies, particularly in high-risk urban areas where outbreak potential is greatest. Full article

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16 pages, 2007 KiB

Open AccessArticle

The Incidence of Scabies in Far North Queensland, Tropical Australia: Implications for Local Clinical Practice and Public Health Strategies

by Mert Hamdi Korkusuz, Maria Eugenia Castellanos, Linton R. Harriss, Allison Hempenstall, Simon Smith and Josh Hanson

Trop. Med. Infect. Dis. 2025, 10(4), 111; https://doi.org/10.3390/tropicalmed10040111 - 18 Apr 2025

Abstract

The recognition and treatment of scabies has been incorporated into Australian guidelines for the prevention of acute rheumatic fever (ARF) and rheumatic heart disease (RHD). The incidence of both diagnosed ARF and RHD is increasing in Far North Queensland (FNQ) in northeast tropical [...] Read more.

The recognition and treatment of scabies has been incorporated into Australian guidelines for the prevention of acute rheumatic fever (ARF) and rheumatic heart disease (RHD). The incidence of both diagnosed ARF and RHD is increasing in Far North Queensland (FNQ) in northeast tropical Australia, but the local burden of scabies is incompletely defined. We reviewed the results of every skin scraping collected in FNQ’s public health system between 2000 and 2023; 121/4345 (2.8%) scrapings were positive, including 19/1071 (1.8%) in the last 5 years of the study; the proportion of scrapings that were positive for scabies declined over the study period. Individuals who tested positive for scabies were no more likely to have had a prior diagnosis of ARF or RHD compared to the matched controls (1/101 (1%) versus 3/101 (3%), p = 1.0). During a median of 14.7 years of follow-up, individuals who tested positive for scabies were also no more likely to have a diagnosis of ARF or RHD than matched controls (2/100 (2%) versus 6/98 (6%); hazard ratio (95% confidence interval): 0.30 (0.06–1.50) p = 0.14). Microbiologically confirmed scabies is uncommon in FNQ and appears to make a limited contribution to the local incidence of ARF and RHD. Full article

(This article belongs to the Section Neglected and Emerging Tropical Diseases)

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10 pages, 2343 KiB

Open AccessCase Report

Non-O1, Non-O139 Vibrio cholerae Bacteremic Skin Infection with Multiple Skin Necrosis: Case Report

by Amer Ibrahim Alomar, Nasreldin Elhadi, Lamya Zohair Yamani, Reema Allahham, Rana Alghamdi, Ibrahim Alhabib, Asim Diab, Nehal Mahmoud, Bashayer AlDossary, Mariam Almejhim, Nouf Al-Romihi, Faye Aldehalan and Reem Al Jindan

Trop. Med. Infect. Dis. 2025, 10(4), 110; https://doi.org/10.3390/tropicalmed10040110 - 17 Apr 2025

Abstract

Non-O1, non-O139 Vibrio cholerae (NOVC) extraintestinal infections are rare, but recently, several clinical incidents have been reported worldwide. Toxigenic V. cholerae is a well-known etiological agent of cholera, responsible for acute dehydrating watery diarrhea. Outbreaks occur in an epidemic seasonal pattern, particularly in [...] Read more.

Non-O1, non-O139 Vibrio cholerae (NOVC) extraintestinal infections are rare, but recently, several clinical incidents have been reported worldwide. Toxigenic V. cholerae is a well-known etiological agent of cholera, responsible for acute dehydrating watery diarrhea. Outbreaks occur in an epidemic seasonal pattern, particularly in countries with poverty and poor sanitation. Strains of NOVC are usually not involved in causing the epidemic or pandemic outbreaks seen with potential strains of V. cholerae serogroup O1 and O139. However, they can still cause severe sporadic cases of intestinal as well as extraintestinal infections. In this study, we investigated a case of extraintestinal infections associated with the NOVC serogroup isolated from a deep closed wound abscess. The isolate was screened for the presence of three major virulence genes, toxR, ctxA, and tcpA. The strain tested positive for the toxR gene encoding the regulatory protein and cholera toxin (ctx) gene and tested negative for the toxin-coregulated pilus (TCP) gene, which is essential for the colonization of the human intestine, causing the severe diarrheal disease cholera. To the best of our knowledge, this is the first case of extraintestinal infection caused by toxigenic Vibrio cholerae non-O1/non-O139 in a hospitalized patient in Saudi Arabia. Full article

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18 pages, 3837 KiB

Open AccessArticle

Phylogeographic Patterns and Genetic Diversity of Anopheles stephensi: Implications for Global Malaria Transmission

by Jehangir Khan, Dongjing Zhang, Saber Gholizadeh, Yidong Deng, Abdul Aziz, Jianhuang Chen, Pir Tariq Shah, Zhiyue Lv and Tao Chen

Trop. Med. Infect. Dis. 2025, 10(4), 109; https://doi.org/10.3390/tropicalmed10040109 - 16 Apr 2025

Abstract

Background: Anopheles stephensi, a primary malaria vector in South Asia, is expanding its geographic range, raising concerns about increased malaria transmission. However, critical aspects of its genetic diversity, population structure, and evolutionary dynamics remain poorly understood in Khyber Pakhtunkhwa (KP), Pakistan, [...] Read more.

Background: Anopheles stephensi, a primary malaria vector in South Asia, is expanding its geographic range, raising concerns about increased malaria transmission. However, critical aspects of its genetic diversity, population structure, and evolutionary dynamics remain poorly understood in Khyber Pakhtunkhwa (KP), Pakistan, an endemic malaria region where An. stephensi is adapting to urban settings, posing challenges for the development of targeted vector control strategies. This study addresses this gap by analyzing COI, COII (cytochrome oxidase subunit I and II), and ITS2 (internal transcribed spacer 2) sequences from An. stephensi populations in KP and comparing them with global isolates. Additionally, egg morphology analysis was conducted to identify the biological form. Methods: Mosquitoes were collected from malaria-endemic districts (Nowshera, Charsadda, and Peshawar) using ovitraps. Eggs were characterized morphologically, and DNA was extracted for PCR amplification of COI, COII, and ITS2 markers. Sequences from 17 Pakistani isolates, along with global sequences, were analyzed. Phylogenetic relationships, haplotype networks, genetic diversity, and neutrality tests (Tajima’s D and Fu’s Fs) were assessed. Results: Egg morphology confirmed the mysorensis form (13–15 ridges per egg) in KP. COI sequences clustered into two subclades (Punjab and KP), with >99% similarity to global isolates. COII and ITS2 sequences showed high similarity (99.46–100%) with populations from China, Iran, India, and Brazil, reflecting strong genetic connectivity rather than distinct regional clustering. Haplotype analysis identified six COI, ten COII, and ten ITS2 haplotypes, with Hap_2 (50.7%) and Hap_1 (43.3%) being the most prevalent in COI, Hap_7 (29.4%) in COII, and Hap_3 (80.8%) in ITS2. Population genetic analysis revealed higher COI diversity in Pakistan and India, with moderate diversity in COII. Neutrality tests suggested balancing selection in COI for both countries, while COII and ITS2 indicated population contraction in Iran. Conclusions: The findings reveal strong genetic connectivity within regions (e.g., Pakistan) and differentiation across global populations of An. stephensi, highlighting its potential for further expansion and adaptation. These insights are critical for informing global malaria control strategies, particularly in regions vulnerable to vector invasion. Full article

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11 pages, 237 KiB

Open AccessArticle

Current Antimicrobial Susceptibility Trends and Clinical Outcomes of Typhoidal Salmonella in a Large Health Authority in British Columbia, Canada

by Calvin Ka-Fung Lo, Merisa Mok, Cole Schonhofer, Kevin Afra and Shazia Masud

Trop. Med. Infect. Dis. 2025, 10(4), 108; https://doi.org/10.3390/tropicalmed10040108 - 15 Apr 2025

Abstract

Background: From 2018 to 2021, travel-related extensively drug-resistant (XDR) Salmonella Typhi was identified in Ontario, Canada. Opportunities remain to characterize typhoidal Salmonella antimicrobial susceptibility trends (including multi-drug resistance phenotypes; MDR) within a large health authority in British Columbia, Canada. Methods: This retrospective study [...] Read more.

Background: From 2018 to 2021, travel-related extensively drug-resistant (XDR) Salmonella Typhi was identified in Ontario, Canada. Opportunities remain to characterize typhoidal Salmonella antimicrobial susceptibility trends (including multi-drug resistance phenotypes; MDR) within a large health authority in British Columbia, Canada. Methods: This retrospective study included patients with Salmonella Typhi or Paratyphi A, B or C bacteremia identified at Fraser Health regional microbiology laboratory from 2018 to 2024. The primary outcome was the proportion of cases with MDR and XDR typhoidal Salmonella. Secondary outcomes included annual antimicrobial susceptibility for ampicillin, ceftriaxone, ciprofloxacin, trimethoprim-sulfamethoxazole, ertapenem, meropenem and azithromycin. Clinical outcomes included hospitalization length, and 30-day mortality, clinical cure and infection relapse. Results: Among 271 patients, most were previously healthy and recently travelled. There were extended spectrum beta-lactamase (1.1%) and MDR (1.5%) typhoidal Salmonella, with no XDR cases observed. In 2024, ciprofloxacin resistance was 96% while susceptibility rates were high for other studied antimicrobials. Within 30 days, no deaths were reported; however, six patients (3%) had infection relapse. Conclusions: Currently, in British Columbia, MDR typhoidal Salmonella remains rare. Empiric ciprofloxacin should be avoided due to persistently high resistance rates. With ongoing travel patterns, it is beneficial for institutions to continue typhoidal Salmonella antimicrobial susceptibility surveillance, and travelers should seek pre-travel health assessments. Full article

(This article belongs to the Special Issue Emerging Trends of Infectious Diseases in Canada)

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