Tropical Medicine and Infectious Disease

14 pages, 2459 KB

Open AccessArticle

Finding the Gaps: Integrated Serosurveillance and Spatial Clustering of Vaccine Preventable Diseases in Samoa, 2018–2019

by Selina Ward, Harriet L. S. Lawford, Benn Sartorius, Helen J. Mayfield, Filipina Amosa-Lei Sam, Sarah Louise Sheridan, Robert Thomsen, Satupaitea Viali and Colleen L. Lau

Trop. Med. Infect. Dis. 2026, 11(1), 9; https://doi.org/10.3390/tropicalmed11010009 - 28 Dec 2025

Abstract

Introduction: Seroprevalence of antibodies for vaccine-preventable diseases (VPDs), due to vaccination or previous infection, can provide a more accurate estimate of immunity compared to vaccination coverage data alone. This study aimed to examine the seroepidemiology and spatial distribution of VPD seroprevalence in Samoa [...] Read more.

Introduction: Seroprevalence of antibodies for vaccine-preventable diseases (VPDs), due to vaccination or previous infection, can provide a more accurate estimate of immunity compared to vaccination coverage data alone. This study aimed to examine the seroepidemiology and spatial distribution of VPD seroprevalence in Samoa in 2018 and 2019. Methods: Dried blood spot (DBS) samples were collected from two nationally representative community-based surveys of participants aged ≥5 years from the Surveillance and Monitoring to Eliminate Lymphatic Filariasis and Scabies from Samoa (SaMELFS) project. DBSs were tested using multiplex bead assays (MBAs) to detect antibodies against measles, rubella, diphtheria, and tetanus. Seroprevalence was estimated at the national and primary sampling unit (PSU) levels, and cluster analysis was completed using SaTScan. Results: Overall, 8394 valid MBA results were analysed across 35 PSUs. The highest overall seroprevalence was observed for tetanus (91.0%; 95% CI: 90.2–91.7), followed by diphtheria (83.7%; 95% CI: 82.7–84.7), rubella (79.3%; 95% CI: 78.2–80.3), and measles (45.8%; 95% CI: 44.8–46.9) with substantial heterogeneity across PSUs. Clusters of seronegativity to measles (relative risk [RR]: 1.16, p < 0.001) and diphtheria (RR: 1.16, p < 0.001) were also identified. Conclusions: These findings demonstrate significant variation in seroprevalence and pockets of low population immunity to multiple VPDs, highlighting the key advantage of an integrated rather than siloed approach. The relatively high seroprevalence to rubella suggests potential community transmission, emphasising the need to strengthen congenital rubella surveillance and improve vaccination coverage. Identifying low immunity to VPDs can provide an early warning to potential outbreak risk and support the Ministry of Health to target public health interventions in higher-risk areas. Full article

(This article belongs to the Special Issue Surveillance of Eliminated and Near-Eliminated Infectious Disease in the Western Pacific Region)

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10 pages, 3332 KB

Open AccessArticle

Incidence and Spatial Mapping of Tuberculosis and Multidrug-Resistant Tuberculosis in Libreville, Republic of Gabon, in 2022

by Casimir Manzengo, Nlandu Roger Ngatu, Stredice Manguinga-Guitouka, Fleur Lignenguet, Ghislaine Nkone-Asseko, Marie Nsimba-Miezi, Nobuyuki Miyatake, Jose Lami-Nzunzu and Tomohiro Hirao

Trop. Med. Infect. Dis. 2026, 11(1), 8; https://doi.org/10.3390/tropicalmed11010008 - 27 Dec 2025

Abstract

Background: Tuberculosis (TB) remains a major global health problem, and the WHO central Africa region continues to bear the heaviest disease burden. Gabon is one of the high-TB-burden countries in the world; however, its national TB program performance remains weak despite financial support [...] Read more.

Background: Tuberculosis (TB) remains a major global health problem, and the WHO central Africa region continues to bear the heaviest disease burden. Gabon is one of the high-TB-burden countries in the world; however, its national TB program performance remains weak despite financial support from international health agencies. Identifying and mapping high-TB- and multi-drug-resistant-TB (MDR-TB)-burden areas for targeted public health interventions was the objective of this study. Methods: A region-wide mixed method study was carried out, comprising ecological design and a desk review, with the use of medical records from TB diagnosis and care units in 12 health facilities located across the capital Libreville, Republic of Gabon, from 1 January through December 2022. Libreville is the region that bears the heaviest TB burden in Gabon. With the collaboration of the Agency for Space Studies and Observations (AGEOS, Gabon), collected data were transferred to and analyzed using QGIS software in order to develop satellite images. Results: In the Libreville health region, there were 4560 cases diagnosed in 2022, representing 77.9% of all cases in the country, with an annual incidence of 509 per 100,000. Spatial mapping of incident cases by county of residence showed that a large majority of the TB cases diagnosed at the CHUL care center in 2022 were from Nzeng-Ayong (range: 36–50 cases) and Owendo (26–35 cases), whereas higher TB incidence at the Nkembo care center was from Nzeng-Ayong (range: 356–455 cases) and Owendo (256–355 cases), followed by Nkembo, Akebe ville, Akebe Baraka, Akebe Plaine/plateau, Angondje, Angondje village, Charbonnages, Bikele, Pk11, Pk12, Pk9, Mindoube I, Mindoube II (66–255 cases), Sotega, and Nkok (46–65 cases). Other counties accounted for less than 45 TB cases. Considering MDR-TB cases, higher incidence was observed in Pk9 county, which accounted for six cases (14.6%), followed by Owendo, accounting for four (9.7%). Discussion: Findings suggest that Nzeng-Ayong and Owendo are high-TB-burden counties in Libreville, whereas Pk9 and Owendo counties are counties categorized as high-MDR-TB-incidence areas. They should be subject to targeted to public health interventions to enhance TB control in Libreville. Full article

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

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22 pages, 2822 KB

Open AccessArticle

Community Participatory Approach to Design, Test, and Implement Interventions That Reduce Risk of Bat-Borne Disease Spillover: A Case Study from Cambodia

by Dou Sok, Sreytouch Vong, Sophal Lorn, Chanthy Srey, Madeline Kenyon, Bruno M. Ghersi, Tristan L. Burgess, Marcia Griffiths, Disha Ali, Elaine M. Faustman, Elizabeth Gold, Jonathon D. Gass, Felicia B. Nutter, Janetrix Hellen Amuguni and Jennifer Peterson

Trop. Med. Infect. Dis. 2026, 11(1), 7; https://doi.org/10.3390/tropicalmed11010007 - 27 Dec 2025

Abstract

Background/Objectives: The USAID STOP Spillover project in Cambodia aimed to reduce the risk of zoonotic virus spillover from bats to humans in bat guano farming communities. Methods: Using participatory tools, such as Outcome Mapping and Trials of Improved Practices, a team [...] Read more.

Background/Objectives: The USAID STOP Spillover project in Cambodia aimed to reduce the risk of zoonotic virus spillover from bats to humans in bat guano farming communities. Methods: Using participatory tools, such as Outcome Mapping and Trials of Improved Practices, a team of local experts and community members collaboratively designed, tested, and refined biosafety and hygiene practices that are acceptable and sustainable to mitigate the risk of bat-borne disease spillover. We tracked progress and rolled out interventions to promote the adoption of safe behaviors that strengthen the understanding of zoonotic disease and reinforce the adoption of safety practices among bat guano producers and their neighbors. The intervention’s effectiveness was evaluated after three-month trials. Results: An improvement in knowledge, attitudes, and risk reduction practices was observed among participants. The primary motivators for adopting these measures were fear of disease, families’ well-being, cost savings, and experience of the COVID-19 pandemic. Conclusions: The community-driven approach fostered a sense of ownership, enabling participants to find the best solutions for their circumstance for long-term sustainability of the intervention. The findings recommended continued community engagement, improved access to biosafety and hygiene resources, and reinforced routine zoonotic disease surveillance. This model can be applied to mitigate emerging infectious disease spillover risks in similar contexts. Full article

(This article belongs to the Section One Health)

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17 pages, 772 KB

Open AccessReview

Spatial Risk Factors of Vector-Borne Diseases in Pacific Island Countries and Territories: A Scoping Review

by Tathiana Nuñez Murillo, Angela Cadavid Restrepo, Helen J. Mayfield, Colleen L. Lau, Benn Sartorius and Behzad Kiani

Trop. Med. Infect. Dis. 2026, 11(1), 6; https://doi.org/10.3390/tropicalmed11010006 - 24 Dec 2025

Abstract

This scoping review aimed to identify and synthesise spatially relevant environmental, demographic, and socio-economic factors associated with vector-borne diseases (VBDs) in Pacific Island Countries and Territories (PICTs), a region particularly vulnerable due to its ecological and climate diversity. A systematic search of PubMed, [...] Read more.

This scoping review aimed to identify and synthesise spatially relevant environmental, demographic, and socio-economic factors associated with vector-borne diseases (VBDs) in Pacific Island Countries and Territories (PICTs), a region particularly vulnerable due to its ecological and climate diversity. A systematic search of PubMed, Scopus, and Web of Science was conducted in March 2025 with no time restrictions, yielding 3008 records. After applying the inclusion criteria, 21 studies were selected for analysis. Environmental factors such as temperature, precipitation, and land cover were consistently associated with increased burden of malaria, dengue, and lymphatic filariasis, while associations with elevation and flooding were mixed or inconclusive. Demographic factors, including population density and household composition, were found to be associated with disease occurrence, although the direction and the strength of these associations varied. Three studies reported a negative association between population density and disease outcomes, including lymphatic filariasis in American Samoa and dengue in New Caledonia. Spatial socioeconomic factors such as low income, unemployment, and limited education were positively correlated with disease burden, particularly lymphatic filariasis and dengue. These findings underscore the importance of spatial determinants in shaping VBD transmission across PICTs and highlight the utility of spatial risk mapping to inform geographically targeted vector control strategies. Notably, infrastructure, health care access, and intra-island mobility remain underexplored in the literature, representing critical gaps for future research. Strengthening surveillance through spatially informed public health planning is essential to mitigate disease burden in this climate-sensitive and geographically dispersed region. Full article

(This article belongs to the Special Issue Spatial Epidemiology and Infectious Diseases in the Context of Changing Climate)

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18 pages, 812 KB

Open AccessArticle

Analysis of Adolescent HIV Care Cascade Outcomes in PEPFAR-Supported Programs in Central America, October 2020–September 2024

by Lissette Raquel Chang, Cristine Gutierrez, Jose Rodas, Nancy Aitcheson, Nasim Farach, Carlos Castaneda, Andres Azmitia Rugg and Benjamin Ryan Phelps

Trop. Med. Infect. Dis. 2026, 11(1), 5; https://doi.org/10.3390/tropicalmed11010005 - 24 Dec 2025

Abstract

To better understand recent adolescent (10–19 years) HIV trends in Central America, we analyzed routine data from countries supported by the United States President’s Emergency Plan for AIDS Relief (PEPFAR): Guatemala, El Salvador, Honduras, Panama, and Nicaragua, over the period from October 2020 [...] Read more.

To better understand recent adolescent (10–19 years) HIV trends in Central America, we analyzed routine data from countries supported by the United States President’s Emergency Plan for AIDS Relief (PEPFAR): Guatemala, El Salvador, Honduras, Panama, and Nicaragua, over the period from October 2020 to September 2024. Key PEPFAR indicators included HIV testing, HIV positivity rates, new treatment initiations, advanced HIV disease (AHD) at diagnosis, viral load coverage (VLC), viral load suppression (VLS), and multi-month dispensing (MMD) uptake for children and adolescents living with HIV (CALHIV) from 10–19 years of age. Since October 2020, the number of HIV tests conducted among adolescents has increased; however, the positivity rate has remained stable at approximately 2%. The number of adolescents initiating treatment increased by 21%. At the same time, VLS has shown steady regional improvement (from 73% to 90%), though VLC is a persistent challenge (80%). Treatment interruption rates have been relatively stable, fluctuating between 2% and 3%. Advanced HIV is high in adolescents new to treatment (34%), especially among females (40%), though cluster of differentiation 4 (CD4) testing at diagnosis has only been collected recently and coverage is not complete. The high prevalence of AHD among adolescents underscores the need to reinforce earlier and more targeted interventions for adolescents, especially in countries with greater HIV prevalence such as Panama and Guatemala. Full article

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

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21 pages, 4659 KB

Open AccessArticle

In Vitro Assessment of the Combined Activity of Amphotericin B and Cu²⁺-1,10-Phenanthroline-5,6-dione Coordination Compound Against Leishmania amazonensis Promastigotes

by Simone Santiago Carvalho de Oliveira, Débora Duarte Batista, Michael Devereux, Malachy McCann, Christiane Fernandes, André Luis Souza dos Santos and Marta Helena Branquinha

Trop. Med. Infect. Dis. 2026, 11(1), 4; https://doi.org/10.3390/tropicalmed11010004 - 24 Dec 2025

Abstract

Leishmaniasis is a severe parasitic disease transmitted by sandflies that affects both humans and animals, with clinical manifestations ranging from cutaneous lesions to life-threatening visceral involvement. Current treatments are limited by toxicity, high cost, and the emergence of drug-resistant strains, underscoring the need [...] Read more.

Leishmaniasis is a severe parasitic disease transmitted by sandflies that affects both humans and animals, with clinical manifestations ranging from cutaneous lesions to life-threatening visceral involvement. Current treatments are limited by toxicity, high cost, and the emergence of drug-resistant strains, underscoring the need for safer and more effective therapeutic strategies. In this study, we investigated the antiparasitic potential of combining Amphotericin B, a drug commonly used for leishmaniasis treatment, with 1,10-phenanthroline-5,6-dione (phendione) coordinated to copper (Cu²⁺-phendione), an experimental coordination compound, against Leishmania amazonensis promastigotes. The combination markedly impaired parasite proliferation, disrupted ultrastructural integrity, and interfered with metabolic activity. Mechanistic analyses revealed the presence of autophagosomes and pronounced mitochondrial alterations in treated parasites, suggesting the induction of cellular stress and the disruption of essential survival pathways. In addition, the treatment reduced the association index with THP-1 cells, indicating a decrease in parasite infectivity. Collectively, these findings demonstrate that the combination of Cu²⁺-phendione and Amphotericin B exerts potent antiparasitic effects through multiple mechanisms. Our results also showed that Cu²⁺-phendione combined with AmB displayed an additive effect, although the isobologram suggested that certain ratios approached synergy. The results support the potential of this combination as a novel chemotherapeutic approach against leishmaniasis and provide a basis for future in vivo studies to evaluate safety, efficacy, and optimal dosing strategies. Full article

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

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20 pages, 1101 KB

Open AccessReview

Clinical Protocols for the Initial Evaluation and Follow-Up of Patients with Chronic Chagas Disease: A Proposal for Referral Centers

by Alejandro Marcel Hasslocher-Moreno, Ana Cristina Ribeiro Rohem, Andrea Rodrigues da Costa, Andréa Silvestre de Sousa, Fernanda de Souza Nogueira Sardinha Mendes, Fernanda Martins Carneiro, Flavia Mazzoli-Rocha, Gilberto Marcelo Sperandio da Silva, Henrique Horta Veloso, Luciana Fernandes Portela, Luiz Henrique Conde Sangenis, Marcelo Teixeira de Holanda, Paula Simplicio da Silva, Roberto Magalhães Saraiva, Sergio Salles Xavier and Mauro Felippe Felix Mediano

Trop. Med. Infect. Dis. 2026, 11(1), 3; https://doi.org/10.3390/tropicalmed11010003 - 20 Dec 2025

Abstract

Chagas disease (CD) remains a major global health challenge and requires standardized, multidisciplinary, and evidence-based clinical approaches. This article aims to present and systematize the model of clinical routines developed at the Clinical Research Laboratory on Chagas Disease (Lapclin-Chagas), INI/Fiocruz, for the initial [...] Read more.

Chagas disease (CD) remains a major global health challenge and requires standardized, multidisciplinary, and evidence-based clinical approaches. This article aims to present and systematize the model of clinical routines developed at the Clinical Research Laboratory on Chagas Disease (Lapclin-Chagas), INI/Fiocruz, for the initial evaluation and longitudinal follow-up of patients with chronic CD. The proposal is intended to serve as a replicable and adaptable framework for referral centers in both endemic and non-endemic settings. Using a descriptive qualitative design, institutional protocols, national and international guidelines, and expert consultations were analyzed to construct a comprehensive care model. The resulting protocol integrates diagnostic pathways (including dual serological confirmation and clinical staging), criteria for etiological treatment, and coordinated multidisciplinary follow-up involving cardiology, gastroenterology, pharmaceutical care, nutrition, psychology, and social support. Specific pathways are also presented for Trypanosoma cruzi (T. cruzi)/HIV coinfection, laboratory accidents, and monitoring of adverse reactions to benznidazole. By consolidating more than three decades of institutional experience into operational workflows, this proposal offers an innovative contribution to the organization of CD care and provides actionable guidance for health systems seeking to improve diagnostic accuracy, therapeutic adherence, patient safety, and long-term outcomes. Full article

(This article belongs to the Special Issue Global Perspectives on Neglected Tropical Diseases: Burden, Science, and Policy Interventions)

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27 pages, 1758 KB

Open AccessReview

The Role of Immunogenetics in the Host–Parasite Interaction of Chagas Disease: Implications for Personalized Medicine

by Muhammad Hassnain, Syeda Mahnoor Bukhari, Tahira Bibi, Syeda Fakhra Waheed, Monica C. Botelho and Waqas Ahmad

Trop. Med. Infect. Dis. 2026, 11(1), 2; https://doi.org/10.3390/tropicalmed11010002 - 19 Dec 2025

Abstract

Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, continues to be a significant global health issue, especially in Latin America, with increasing international prevalence due to migration. Despite advancements in diagnosis and treatment, it remains a neglected tropical disease characterized by [...] Read more.

Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, continues to be a significant global health issue, especially in Latin America, with increasing international prevalence due to migration. Despite advancements in diagnosis and treatment, it remains a neglected tropical disease characterized by significant morbidity and mortality, mainly influenced by the complex interaction between parasite diversity and host immune responses. Importantly, the remarkable genetic diversity of T. cruzi lineages also contributes to clinical heterogeneity, influencing immune evasion, therapeutic responses, and vaccine feasibility. This review analyzes the impact of immunogenetics on host–parasite interactions in Chagas disease and explores its implications for personalized therapy approaches. Recent research, particularly over the last decade, has indicated that processes including antigenic variation, extracellular vesicle-mediated regulation, and disruption of host signaling pathways facilitate parasite persistence. Host genetic variables significantly influence susceptibility, disease development, and treatment outcomes, including changes in Human Leukocyte Antigen (HLA) genes, cytokine gene polymorphisms, and immunogenetic determinants of cardiac pathology. These findings underscore the potential of immunogenetic markers as tools for prognosis and as targets for personalized therapies. However, there are still considerable research deficiencies. Inadequate comprehension of gene–environment interactions, lack of representation of varied populations, and inconsistencies in study design limit the use of immunogenetic findings in therapeutic settings. At present, the concept of personalized medicine in Chagas disease remains largely aspirational, better understood as a framework for precision public health or stratified interventions guided by host immunogenetic and parasite lineage data. Addressing these issues necessitates comprehensive genomic research, mechanistic investigations of host–parasite interactions, and clinical validation of genetic markers. This study emphasizes the necessity of incorporating immunogenetics into personalized patient management strategies based on existing evidence. This integration has the potential to improve diagnosis, enhance treatment efficacy, and inform preventive interventions, thereby advancing personalized therapy for Chagas disease. Full article

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

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16 pages, 1778 KB

Open AccessArticle

Spatial Distribution and Biodiversity of Anopheles Mosquito Species Across Climatic Zones in Burkina Faso: Implications for Malaria Vector Control

by Odette N. Zongo, Emmanuel Kiendrebeogo, Bazoumana B. D. Sow, Mahamadi Kientega, Inoussa Toé, Roger Sanou, Saberé O. G. Yemien, Grégoire Sawadogo, Honorine Kaboré, Achaz Agolinou, Nouhoun Traore, Patric Stephane Epopa, Abdoul Azize Millogo, Abdoulaye Niang, Moussa Namountougou, Hamidou Maiga and Abdoulaye Diabaté

Trop. Med. Infect. Dis. 2026, 11(1), 1; https://doi.org/10.3390/tropicalmed11010001 - 19 Dec 2025

Abstract

Malaria transmission in sub-Saharan Africa is dominated by the An. gambiae complex and An. funestus group, whose distribution varies across ecological settings. Secondary species occur at lower densities, but their role in transmission may differ from one locality to another depending on local [...] Read more.

Malaria transmission in sub-Saharan Africa is dominated by the An. gambiae complex and An. funestus group, whose distribution varies across ecological settings. Secondary species occur at lower densities, but their role in transmission may differ from one locality to another depending on local conditions. Assessing Anopheles biodiversity using ecological indices is therefore essential to characterise their diversity and relative abundance. This study investigated the biodiversity and spatial distribution of Anopheles species across the three climatic zones of Burkina Faso to guide effective vector control strategies. Indoor resting mosquitoes were collected from 67 health districts across the 13 regions of Burkina Faso between September and December 2022 using pyrethroid spray catches. A total of 30,521 Anopheles mosquitoes were identified, with An. gambiae s.l. dominating (94.4%). The Sudano-Sahelian zone recorded the highest abundance, followed by the Soudanian and Sahelian zones. Biodiversity decreased from humid southern to arid northern areas, with the Soudanian zone showing the highest diversity. Molecular analysis of 2026 An. gambiae s.l. specimens revealed marked heterogeneity: An. coluzzii predominated in Sahelian (74.9%) and Sudano-Sahelian (71.2%) zones, while An. gambiae s.s. was most frequent in the Soudanian zone (53.8%). These results highlight spatial and ecological differences in Anopheles composition across Burkina Faso and emphasize the need for locally adapted malaria vector control strategies. Full article

(This article belongs to the Special Issue Vector-Borne Diseases in a Changing Climate: Transmission Dynamics and Epidemiological Shifts)

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15 pages, 673 KB

Open AccessArticle

Multi-Target Molecular Detection of Sexually Transmitted Infections in Women Living with HIV in Northeastern Brazil

by Melina Vieira Alves, Letícia Alves dos Santos Silva, Maria Luísa Rodrigues Nolasco, Anny Beatriz de Oliveira Gama, Márcia Guimarães da Silva and Marcus Vinicius de Aragão Batista

Trop. Med. Infect. Dis. 2025, 10(12), 354; https://doi.org/10.3390/tropicalmed10120354 - 18 Dec 2025

Abstract

Co-infection by human papillomavirus (HPV) and human immunodeficiency virus (HIV) facilitates cervical carcinogenesis, and additional cofactors such as other sexually transmitted infections (STI) further aggravate this scenario. This study aimed to validate a molecular detection strategy for Chlamydia trachomatis, Trichomonas vaginalis and [...] Read more.

Co-infection by human papillomavirus (HPV) and human immunodeficiency virus (HIV) facilitates cervical carcinogenesis, and additional cofactors such as other sexually transmitted infections (STI) further aggravate this scenario. This study aimed to validate a molecular detection strategy for Chlamydia trachomatis, Trichomonas vaginalis and Neisseria gonorrhoeae and to assess the association of these infections with cervical lesions in HPV-positive women living with HIV in Northeastern Brazil. In total, 155 samples were collected from CRIST/AIDS. After microorganism detection by conventional PCR, a multiplex PCR was standardized and validated. A prevalence of 9.03% was observed for C. trachomatis and 6.45% for T. vaginalis, with 0.64% co-infection. In addition, infection with both STIs showed a prevalence of 0.64%. Among HPV-positive women, high-risk genotypes accounted for 70.9% of cases, with HPV-16 being the most prevalent (35.5%). Overall, 18.2% of women presented cervical lesions, and 13.2% of those with co-detection of C. trachomatis and T. vaginalis were associated with high-grade squamous intraepithelial lesions (HSIL). These findings highlight the clinical relevance of screening for multiple STIs in HPV-positive women living with HIV and support the incorporation of multiplex molecular testing into public health strategies to improve early detection and targeted management. Full article

(This article belongs to the Special Issue HIV Testing, Prevention and Care Interventions, 2nd Edition)

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15 pages, 1417 KB

Open AccessArticle

Respiratory Illness and Diarrheal Disease Surveillance in U.S. Military Personnel Deployed to Southeast Asia for Military Exercises from 2023–2025

by Sidhartha Chaudhury, Paphavee Lertsethtakarn, Piyawan Chinnawirotpisan, Nattaya Ruamsap, Worachet Kuntawunginn, Chadin Thongpiam, Kingkan Pidtana, Kittijarankon Phontham, Saowaluk Wongarunkochakorn, Montri Arsanok, Kamonporn Poramathikul, Parat Boonyarangka, Paksathorn Kietsiri, Wilawan Oransathit, Siriphan Gonwong, Patcharawalai Wassanarungroj, Panida Nobthai, Nuanpan Khemnu, Thipwipha Phonpakobsin, Wudtichai Manasatienkij, Joonlasak Khajohn, Chonthicha Klungthong, Nillawan Buathong, Sabaithip Sriwichai, Siriporn Sornsakrin, Umaporn Suksawad, Susie Leonardia-Santiago, Maria Theresa Valderama, John Mark Velasco, Paula Corazon Diones, Matthew Pascual, Chris Mahabir, Kathryn A. McGuckin and Daniel M. Boudreaux Show full author list Hide full author list

Trop. Med. Infect. Dis. 2025, 10(12), 353; https://doi.org/10.3390/tropicalmed10120353 - 17 Dec 2025

Abstract

The Indo-Pacific region hosts several annual military exercises that involve the deployment of thousands of U.S. and partner-nation military personnel. Respiratory and diarrheal diseases pose a significant health risk to exercise participants and represent a substantial portion of medical encounters and lost duty [...] Read more.

The Indo-Pacific region hosts several annual military exercises that involve the deployment of thousands of U.S. and partner-nation military personnel. Respiratory and diarrheal diseases pose a significant health risk to exercise participants and represent a substantial portion of medical encounters and lost duty days. We conducted surveillance for respiratory and diarrheal illness at the Cobra Gold and Balikatan military exercises in Thailand and the Philippines from 2023–2025. Through coordination with health providers in the field, military personnel that reported acute symptoms were asked to provide a nasopharyngeal swab or stool sample. These samples were transported to a field lab and tested by PCR for common respiratory and diarrheal pathogens. Follow-up analyses included bacterial culture, antimicrobial susceptibility testing, and viral whole-genome sequencing. From 84 respiratory and 61 diarrheal samples analyzed, we found that respiratory illness was primarily attributed to rhinoviruses/enteroviruses (23%), common coronaviruses (21%), and SARS-CoV-2 (11%) while diarrheal disease was attributed to a high rate of diarrheagenic E. coli (73%) and norovirus (20%), followed by Salmonella spp. (18%) and Campylobacter spp. (13%). Our findings highlight the distinct etiologies of respiratory and diarrheal disease in military field settings and demonstrate the feasibility of conducting real-time infectious disease surveillance in operational environments. Full article

(This article belongs to the Special Issue Military Medicine: An Everlasting War against Tropical and Infectious Diseases)

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12 pages, 464 KB

Open AccessArticle

The Tolerability of the Dengue Vaccine TAK-003 (Qdenga^®) in German Travelers: The Results of a Prospective Survey

by Tomas Jelinek, Juliane Kramm, Maik Wagner and Claudia Jelinek

Trop. Med. Infect. Dis. 2025, 10(12), 352; https://doi.org/10.3390/tropicalmed10120352 - 16 Dec 2025

Abstract

Background: The global incidence of dengue has markedly increased over the last decades. Consequently, the risk of infection has increased significantly, resulting in record numbers of imported cases in various European countries and elsewhere in 2024. Methods: In early 2023, TAK-003, a novel, [...] Read more.

Background: The global incidence of dengue has markedly increased over the last decades. Consequently, the risk of infection has increased significantly, resulting in record numbers of imported cases in various European countries and elsewhere in 2024. Methods: In early 2023, TAK-003, a novel, live attenuated vaccine against dengue, became available in Germany. At the Berlin Centre for Travel & Tropical Medicine, we delivered 56,459 doses during the first 24 months of its availability, from February 2023 to February 2025. To obtain data on the tolerability of the vaccine in travelers, an active follow-up survey was initiated. Results: In total, 30,306 (53.7%) vaccinees agreed to being contacted. Of these, 11,827 (39.0%) completed an anonymous questionnaire ≥ 4 weeks after the vaccination. Overall, 6856 (58.0%) were female, and 565 (4.8%) reported having had a prior dengue infection. The average age was 38.3 years (range 4–86 years). An endemic area had been visited by 6309 subjects before answering the questionnaire, and among these, 46 (0.7%) reported a dengue infection while abroad. All cases were mild, and no complications were reported. TAK-003 was applied with other vaccines in 7363 (62.3%) travelers. Local adverse reactions, mostly local pain, were reported by 5263 (47.5%) subjects. Systemic reactions were reported by 4891 subjects (41.4%) and were most frequently fatigue, myalgia, and flu-like symptoms. The majority of adverse events manifested in the second week after vaccination (median 8 days) and were mostly limited to a duration of 1–3 days. A macular exanthema was described by 1844 subjects (15.6%), typically during the second week after the vaccination. Conclusions: Side effects were frequently reported but generally well tolerated. Age groups above 50 years showed a decline in reactogenicity. Co-vaccination was frequent and led to an increase in systemic adverse events. Denominator data of the study population suggest a strong reporting bias towards adverse events. This survey adds evidence of the chronology and characteristics of adverse events associated with TAK-003 and may support decision making when vaccinating dengue-naïve travelers. Full article

(This article belongs to the Section Travel Medicine)

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12 pages, 932 KB

Open AccessArticle

Spatial Analysis of Drug-Resistant Tuberculosis in Colombia (2020–2023): Departmental Rates, Clusters, and Associated Factors

by Brayan Patiño-Palma, Sandra Chacon-Bambague, Farlhyn Bermudez-Moreno, Carmencita Peña-Briceño, Juan Bustos-Carvajal and Florencio Arias-Coronel

Trop. Med. Infect. Dis. 2025, 10(12), 351; https://doi.org/10.3390/tropicalmed10120351 - 15 Dec 2025

Abstract

Background: Drug-resistant tuberculosis (DR-TB) constitutes a serious threat to global public health due to the increase in strains resistant to multiple drugs, especially isoniazid and rifampicin. This resistance increases mortality, estimated at 25.6% globally, and complicates treatments due to its high toxicity and [...] Read more.

Background: Drug-resistant tuberculosis (DR-TB) constitutes a serious threat to global public health due to the increase in strains resistant to multiple drugs, especially isoniazid and rifampicin. This resistance increases mortality, estimated at 25.6% globally, and complicates treatments due to its high toxicity and cost. Materials and Methods: A quantitative ecological study was carried out with data on drug-resistant tuberculosis reported in Sivigila in the years (2020–2023) SIVIGILA database. 1694 cases were analyzed, considering sociodemographic variables such as age, sex, nationality and prioritized population groups. Departmental rates per 100,000 inhabitants were calculated with DANE projection, from these choropleth maps were developed. Applying a Kulldorff spatial scan under a Poisson model using the SMERC package of R (version 4.5.1), with windows centered on each department and Monte Carlo simulation contrast to identify high-risk clusters (RR > 1). Results: (DR-TB) Predominantly in men aged 30–44 years, with a progressive increase until 2023 (IRR = 2.11). Three high-risk clusters were detected in the southwest and center of the country. Discussion: Drug-resistant tuberculosis in Colombia showed a sustained increase in the years of study, with a cumulative increase of 110% compared to 2020, associated with economically active people more exposed due to occupational and social factors. The greatest burden was observed in the general population. Cases also increased in groups with social and health vulnerability conditions. Conclusions: The departments of Risaralda, Meta, and Valle del Cauca presented the highest drug resistance rates in Colombia. Full article

(This article belongs to the Special Issue Surveillance, Modelling, and Risk Mapping of Tropical Infectious Diseases)

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2 pages, 158 KB

Open AccessCorrection

Correction: Majeed et al. Mapping Evidence on the Regulations Affecting the Accessibility, Availability, and Management of Snake Antivenom Globally: A Scoping Review. Trop. Med. Infect. Dis. 2025, 10, 228

by Ramsha Majeed, Janette Bester, Kabelo Kgarosi and Morné Strydom

Trop. Med. Infect. Dis. 2025, 10(12), 350; https://doi.org/10.3390/tropicalmed10120350 - 15 Dec 2025

Abstract

Error in Table [...] Full article

(This article belongs to the Special Issue Recent Advances in Snakebite Envenoming Research)

17 pages, 972 KB

Open AccessArticle

Concurrent Assessment of Synthetic and Natural Compounds on the Proliferation of Toxoplasma gondii in In Vitro Models

by Alejandro Zamora-Vélez, Derly Lorena Vanegas, María Camila Fernández, Gerardo Ramos, Edwar Cortés, Ailan Farid Arenas, Néstor Cardona, Jessica Palacio-Rodriguez, Juan David Valencia-Hernandez, Luz Angela Veloza, Juan Carlos Sepúlveda-Arias and Jorge Enrique Gómez-Marín

Trop. Med. Infect. Dis. 2025, 10(12), 349; https://doi.org/10.3390/tropicalmed10120349 - 13 Dec 2025

Abstract

Concurrent evaluation of the antiparasitic efficacy of synthetic and natural compounds can provide novel insights into the development of anti-Toxoplasma drugs. We assessed 16 synthetic compounds and two fractions derived from the leaves of Tabebuia rosea and Tabebuia chrysantha tree species for [...] Read more.

Concurrent evaluation of the antiparasitic efficacy of synthetic and natural compounds can provide novel insights into the development of anti-Toxoplasma drugs. We assessed 16 synthetic compounds and two fractions derived from the leaves of Tabebuia rosea and Tabebuia chrysantha tree species for their in vitro activity against live parasites, employing strains that express green fluorescent protein and specific identification of bradyzoites using an anti-BAG1 monoclonal antibody. This study successfully identified several promising synthetic compounds with potent anti-Toxoplasma activity and favorable in vitro selectivity profiles, notably pyrazoline 2 and thiazolidinone 9. One thiazolidinone compound exhibited significant activity against extracellular tachyzoites, whereas one tree fraction demonstrated excellent activity against both tachyzoites and bradyzoites. Additionally, their in silico ADMET properties suggest their potential for good in vivo performance and CNS penetration. Although the natural extracts showed less potency in their crude form, they provide a basis for future purification efforts. The simultaneous evaluation of compounds sourced from diverse discovery pipelines can offer valuable insights into the development of drugs that target various biological pathways. Full article

(This article belongs to the Special Issue Advances in Toxoplasma gondii Infection Research)

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7 pages, 622 KB

Open AccessCommentary

Ending the TB Crisis in Low- and Middle-Income Countries of the Eastern Mediterranean Region—Overcoming Inaction Through Strategical Leaps

by Santosha Kelamane, Ghada Muhjazi, Nevin Wilson and Martin van den Boom

Trop. Med. Infect. Dis. 2025, 10(12), 348; https://doi.org/10.3390/tropicalmed10120348 - 12 Dec 2025

Abstract

Tuberculosis (TB) remains a public health threat in low- and middle-income countries (LMICs) of the World Health Organization (WHO) Eastern Mediterranean Region (EMR), driven by a combination of social determinants including undernutrition, fragile health systems, conflict-related disruptions, human mobility and displacement, sub-optimal programmatic [...] Read more.

Tuberculosis (TB) remains a public health threat in low- and middle-income countries (LMICs) of the World Health Organization (WHO) Eastern Mediterranean Region (EMR), driven by a combination of social determinants including undernutrition, fragile health systems, conflict-related disruptions, human mobility and displacement, sub-optimal programmatic implementation, and insufficient domestic investment. These programmatic and governance constraints operate within a broader geopolitical context marked by conflict, sanctions, protracted crises, and large-scale displacement, which further limit countries’ ability to deliver uninterrupted TB services. In 2023, the region’s TB incidence was estimated at 116 per 100,000 population, with Pakistan alone accounting for about 73% of the regional burden. Despite a multitude of efforts, progress in reducing the TB burden in the EMR remains slow, with high case detection and treatment coverage gaps, low uptake of TB preventive treatment (TPT), underutilization of WHO-recommended rapid diagnostics, and only 25% of drug-resistant TB (DR-TB) cases initiated on treatment. Vulnerable populations, including internally displaced persons, migrants, refugees, prisoners, and returnees, continue to face major access barriers, and cross-border TB collaboration remains limited. This commentary reasons that the slow pace of TB burden reduction in the region is not only a biomedical or resource issue but also a reflection of structural and governance shortcomings. It proposes a ten-point strategic vision focused on building a sustainable ecosystem, enhancing primary healthcare systems, adopting people-centered and rights-based approaches, leveraging artificial intelligence, and gradually reducing dependency on external donors where feasible. However, in highly fragile settings such as Yemen or Somalia, domestic financing remains limited, and sustained external support will continue to be indispensable. The commentary calls for stronger national leadership, inclusive stakeholder engagement, and increased domestic financing to deliver integrated and resilient TB services. Ending TB in the EMR is within reach, but it requires boldly committed, coordinated, and country-led action. Full article

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

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17 pages, 741 KB

Open AccessArticle

Optimization of Case Finding and Preventive Treatment Among Household Contacts of People with Tuberculosis in Zimbabwe

by Tawanda Mapuranga, Collins Timire, Ronald T. Ncube, Sithabiso Dube, Nqobile Mlilo, Cynthia Chiteve, Owen Mugurungi, Fungai Kavenga, Manners Ncube, Nicholas Siziba, Selma Dar Berger, Talent Maphosa, Macarthur Charles, Julia Ershova and Riitta A. Dlodlo

Trop. Med. Infect. Dis. 2025, 10(12), 347; https://doi.org/10.3390/tropicalmed10120347 - 10 Dec 2025

Abstract

Systematic screening of household contacts (HHCs) of people with tuberculosis (TB) and starting them on either TB treatment or tuberculosis preventive treatment (TPT) reduces TB incidence. This project supported HHC management in six health facilities in Zimbabwe through the provision of CXR services, [...] Read more.

Systematic screening of household contacts (HHCs) of people with tuberculosis (TB) and starting them on either TB treatment or tuberculosis preventive treatment (TPT) reduces TB incidence. This project supported HHC management in six health facilities in Zimbabwe through the provision of CXR services, reimbursement of transport costs for HHCs, and provision of fuel and refreshments for healthcare workers involved in contact tracing. We describe TB and TPT cascades among the HHCs of index patients with all forms of TB. We enrolled 251 index patients who listed 794 HHCs: 551 (69%) HHCs of 158 index patients were traced and 520 (94%) screened for TB. Of the 502 who were referred to clinics, 362 (72%) reached the clinic. Among 520 HHCs, 324 (62%) underwent CXR screening and 18 (5%) had CXRs suggestive of TB. The yield of TB was 2.3% (12/520), with CXR detecting eight people who had not reported TB symptoms. Of the 311 who were assessed for TPT eligibility, 126 (41%) started TPT and 119 were assessed for TPT outcomes. Of these, 111 (93%) had successful TPT outcomes. The median times to starting TB treatment and TPT were 7 days and 11 days, respectively. The intervention facilitated timely access to healthcare services and a high yield of TB detection. Full article

(This article belongs to the Special Issue New Perspectives in Tuberculosis Prevention and Control)

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7 pages, 4885 KB

Open AccessCase Report

Hidden in Plain Sight: Peritoneal Tuberculosis Mimicking Ovarian Neoplasm—A Case Report

by Dolfus Santiago Romero-Rojas, Andrés Rojas-Torres, Brenda Amell-Barón, David Serna, Luis Vasquez-Pinto, Luis Eduardo Barrera-Herrera and Javier Iván Lasso-Apraez

Trop. Med. Infect. Dis. 2025, 10(12), 346; https://doi.org/10.3390/tropicalmed10120346 - 9 Dec 2025

Abstract

Tuberculosis remains the deadliest infectious disease worldwide. Among extrapulmonary forms, peritoneal tuberculosis stands out as a rare and challenging diagnosis, often mistaken for intra-abdominal neoplasms or peritoneal carcinomatosis. The clinical, paraclinical, and imaging findings are similar and sometimes indistinguishable between the two entities, [...] Read more.

Tuberculosis remains the deadliest infectious disease worldwide. Among extrapulmonary forms, peritoneal tuberculosis stands out as a rare and challenging diagnosis, often mistaken for intra-abdominal neoplasms or peritoneal carcinomatosis. The clinical, paraclinical, and imaging findings are similar and sometimes indistinguishable between the two entities, making the diagnosis a challenge for the treating physician. Here, we present the case of a young woman with chronic constitutional symptoms who presented to the emergency department with abdominal pain and ascites. An initial differential diagnosis of peritoneal carcinomatosis was considered based on findings in the peritoneal fluid and abdominal CT scan, leading to diagnostic laparoscopy. Histopathological examination of the samples revealed non-caseating granulomas involving the peritoneum, with no findings suggestive of malignancy. Subsequently, molecular testing for Mycobacterium tuberculosis was positive in the biopsies and peritoneal fluid, establishing the diagnosis of peritoneal tuberculosis. This case highlights the importance of awareness of peritoneal tuberculosis as a differential diagnosis of ascites and its significant potential to mimic other pathologies. Full article

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

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14 pages, 1069 KB

Open AccessArticle

Serologic Evidence of Circulation of Six Arboviruses (Dengue Virus, Chikungunya Virus, Zika Virus, Rift Valley Virus, Yellow Fever Virus, Crimean-Congo Hemorrhagic Fever Virus) in Four Regions of Burkina Faso, West Africa

by Armel Moumouni Sanou, Achille Sindimbasba Nikiéma, Aurélie Sausy, Jeoffray Diendéré, Mathuola Nina Genéviève Ouattara, Arielle Bettina Sandra Badiel, Isidore Bonkoungou, Henri Gautier Ouédraogo and Judith M. Hübschen

Trop. Med. Infect. Dis. 2025, 10(12), 345; https://doi.org/10.3390/tropicalmed10120345 - 9 Dec 2025

Abstract

Apart from some information on dengue virus (DENV), there is limited data on the circulation of arboviruses in Burkina Faso. The aim of this study was to investigate antibody prevalence against six arboviruses in four regions of the country to document previous virus [...] Read more.

Apart from some information on dengue virus (DENV), there is limited data on the circulation of arboviruses in Burkina Faso. The aim of this study was to investigate antibody prevalence against six arboviruses in four regions of the country to document previous virus exposure. Serum samples collected between August 2018 and December 2022 from people infected with viral hepatitis B and C in Bobo-Dioulasso were used to detect IgG antibodies against DENV, Chikungunya virus (CHIKV), Zika virus (ZIKV), Yellow fever virus (YFV), Rift Valley fever virus (RVFV) and Crimean-Congo hemorrhagic fever virus (CCHFV) using commercial ELISA kits. A total of 1808 serum samples, accompanied by basic epidemiologic data (sex, age and residency) were included in this study. We observed an IgG antibodies seroprevalence of 75.4% for DENV, 30.8% for CHIKV, 2.9% for ZIKV, 1.2% for RVFV, 1.1% for CCHFV and 1.1% for YFV. Age, sex, and place of residence were significantly associated with seropositivity for DENV and age and sex with CHIKV seropositivity. The results suggested widespread circulation of DENV and CHIKV and possible circulation of CCHFV and RVFV in humans in Burkina Faso. The importance of strengthening arbovirus surveillance by including additional arboviruses in the diagnostic panel is emphasized. Full article

(This article belongs to the Section Vector-Borne Diseases)

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