Tropical Medicine and Health最新文献

Background: Entamoeba moshkovskii, a morphologically indistinguishable but genetically distinct species from E. histolytica, has recently emerged as a potential cause of human diarrhoeal disease. Despite its increasing global recognition, its epidemiological role, genetic diversity, and transmission dynamics remain poorly defined, particularly in the Indian subcontinent.

Methods: A prospective study was conducted among 300 hospitalised patients with acute diarrhoea in Northern India to determine the molecular prevalence and phylogenetic diversity of E. moshkovskii. Stool samples were examined microscopically and tested using a species-specific real-time polymerase chain reaction (PCR) assay targeting the 18S rRNA gene. Positive amplicons were sequenced bidirectionally and compared with global reference sequences to infer genetic relationships and lineage divergence.

Results: E. moshkovskii DNA was detected in 17 of 300 patients (5.7%; 95% confidence interval 3.3-8.9%), with higher detection among male and paediatric participants. Twelve isolates yielded high-quality sequences showing 99-100% identity with reference strains, while three exhibited a reproducible thymine-to-purine substitution at position 1655. Phylogenetic reconstruction revealed three major clusters-human, animal, and environmental-with most isolates forming a human-associated lineage and two clustering with non-human strains, suggesting cross-ecological transmission.

Conclusions: This study provides the first sequence-confirmed evidence of E. moshkovskii infection in Northern India and demonstrates emerging genetic diversity among clinical isolates. The coexistence of clonal and divergent strains highlights complex transmission pathways involving environmental and zoonotic reservoirs. These findings underscore the need to incorporate E. moshkovskii into molecular diagnostic algorithms and diarrhoeal disease surveillance within a One Health framework.

Background: Acute undifferentiated febrile illness (AUFI) represents a major health challenge in tropical regions due to its wide range of etiologies. In Villeta, Colombia, previous studies investigated common causes such as malaria, arboviral diseases, leptospirosis and rickettsiosis, as well as several neglected bacterial agents. However, some patients remained without an identified etiology, underscoring the need for broader approaches to uncover other potential causes. Therefore, the aim of the present study was to investigate into other potential bacterial causes of AUFI through advanced molecular strategies utilizing 16S rRNA sequencing.

Methods: The study analyzed AUFI patient samples previously screened for fourteen pathogens. The V3-V9 hypervariable region of the 16S rRNA gene was amplified from whole-blood DNA of unresolved cases and sequenced using the Oxford Nanopore GridION platform. Reads were filtered, quality-checked, and taxonomically classified using the SILVA database.

Results: Eight samples from individuals without evidence of infection or recent exposure to previously screened pathogens were selected for 16S rRNA sequencing. DNA quality and integrity were confirmed, and enrichment produced high-quality amplicons for all samples. Sequencing generated high-quality reads overwhelmingly dominated by Francisella, representing over 93% of classified reads, followed by Coxiella and Arcobacter.

Conclusions: This study provides the first molecular evidence of Francisella in whole-blood from febrile patients in Colombia. Findings highlight its potential role in AUFI, demonstrate the value of 16S rRNA barcoding, and underscore the need for expanded surveillance of highly neglected bacterial taxa.

The health impacts of climate change are increasingly evident in Pacific Island Countries and Territories (PICTs), a group of 22 nations facing significant and existential threats to their populations. This paper investigates the ways in which climate change exacerbates existing health issues in this vulnerable region, focusing on both communicable and non-communicable diseases, and the dynamic relationship between human and planetary health. Rapid urbanization, changes in food systems, and the ongoing epidemiological transition from infectious to chronic diseases reflect the complex interplay of colonization, globalization, and a changing climate. This paper reviews the unique climate challenges faced by PICTs, including rising sea levels, extreme weather events, and their impacts on food security, water resources, and healthcare. We explore the environmental and social determinants of health while highlighting how climate-induced changes compromise the health and well-being of communities throughout the Pacific region. We discuss the increasing prevalence of vector-borne and waterborne diseases, the exacerbation of the region's immense noncommunicable disease burden, and the profound mental health impacts of climate change. The economic implications of these changes, particularly on tourism and fisheries, are also explored. Despite these challenges, PICTs have demonstrated remarkable resilience and remain at the forefront of global climate advocacy. This analysis underscores the urgent need for international solidarity and action to address climate change and protect the health and well-being of the vulnerable Pacific region.

Introduction: Hepatitis B virus (HBV) infection remains a significant global health threat, with over 296 million individuals living with chronic HBV and more than 820,000 annual deaths due to related complications. Healthcare workers (HCWs) are at heightened risk due to occupational exposure, especially in sub-Saharan Africa, where HBV prevalence and health system limitations compound their vulnerability. Despite the availability of an effective vaccine, adherence to the three-dose HBV vaccination schedule among HCWs in Nigeria remains suboptimal. This study seeks to explore the psychosocial and digital factors influencing non-adherence to the HBV vaccination schedule among HCWs in Nigeria, with the aim of informing more targeted and effective interventions.

Methodology: A cross-sectional survey was conducted among 530 healthcare workers at FMC Keffi to assess Hepatitis B vaccine uptake and its determinants. Data were collected using a structured, pre-validated questionnaire covering vaccination status, knowledge, attitudes, barriers, and digital access. Statistical analyses included descriptive statistics, Chi-square tests, binary logistic regression, mediation (PROCESS Model 4), and moderation analyses. These methods evaluated the direct and indirect effects of knowledge, attitudes, occupational exposure, and digital intervention beliefs on vaccine adherence, with gender assessed as a moderating variable.

Results and discussion: Among 530 healthcare workers at FMC Keffi, only 19.4% were fully vaccinated against Hepatitis B, while 72.6% had received at least two doses. Mediation analysis showed that knowledge had no significant direct or indirect effect on vaccine uptake (p = 0.21), whereas attitude was a strong predictor (B = - 9.85, p < 0.001). Occupational exposure significantly influenced adherence (χ2 = 33.00, p < 0.001), as none of the unexposed were fully vaccinated. Gender moderated the attitude-uptake link, with females showing stronger associations. Digital access remained low, limiting the effectiveness of digital intervention strategies.

Conclusion: This study concludes that HBV vaccine adherence among healthcare workers is influenced more by attitudinal factors, occupational exposure, and gender dynamics than by knowledge alone. Digital intervention strategies remain underutilized due to limited access. To improve vaccine uptake, health systems must adopt multifaceted approaches that prioritize behavioral insights, gender sensitivity, and equitable access to digital health resources.

Background: The emergence of resistance to synthetic (chemical) insecticides along with their harmful effects on human health, non-target organisms and the environment necessitates the development of new complementary bioinsecticides that are effective, environmentally friendly, biodegradable and target-specific. This study was undertaken to evaluate larvicidal activities of 80% methanol and n-hexane extracts of four plants that are traditionally used by communities against mosquitoes.

Methods: The dried plant parts of Ocimum lamiifolium, Amaranthus hybridus, Premna schimperi, and Lepidium sativum were extracted with 80% methanol and n-hexane solvents. Bioinsecticidal activities of these extracts were evaluated under laboratory condition in the range of 62.5-2000 ppm against late 3rd to early 4th instar larvae of An. arabiensis, An. stephensi and Ae. aegypti mosquitoes. Larval mortality was observed after 24 h of exposure. The mortality data were subjected to probit analysis to determine LC₅₀ and LC₉₀ values.

Results: In the concentration ranges of 62.5-2000 ppm, the LC₅₀ and LC₉₀ values of the most potent n-hexane extracts tested plants; Ocimum lamiifolium against An. arabiensis, An. stephensi and Ae. aegypti with a general ranges 666.07 to 1278.22, and 1920.82 to 2139.91, and Amaranthus hybridus against An. stephensi and Ae. aegypti 412 to 1426.03 and 736.150 to 1222.62, Lepidium sativum and Premna schimperi against An. arabiensis exhibited 100% larvicidal activity with LC₅₀ and LC₉₀ values ranges 713.25 to 1278.22, and 636.76 to 988.90, respectively. All the n-hexane extracts showed larvicidal activities.

Conclusions: The n-hexane crude extracts of the tested plants have the potential to be used as bioinsecticides against larvae of An. arabiensis, An. stephensi and Ae. aegypti. Therefore, it is necessary to undertake studies that focus on bioassay-guided isolation, purification and structural elucidation of active compound (s) from the most active n-hexane fractions of the tested plants to develop a product that may complement the current existing vector control tools.

Background: Africa has made notable progress against Neglected Tropical Diseases (NTDs) using a whole-of-society approach that involved everyone, though sub-Saharan Africa still faces major challenges. Since the Expanded Special Project for the Elimination of Neglected Tropical Diseases (ESPEN) was launched in 2016, over 500 million people have been treated for NTDs like onchocerciasis, lymphatic filariasis, schistosomiasis, and soil-transmitted helminthiases. Nineteen African countries have eliminated at least one NTD, yet 44 out of 52 tracked nations still need preventive chemotherapy for multiple diseases. In 2022, 81 million people received schistosomiasis treatment, but adult coverage remains low due to limited praziquantel access. This paper documents lessons and success stories from regional initiatives such as the African Programme for Onchocerciasis Control (APOC), the Onchocerciasis Control Programme in West Africa (OCP), and the Guinea Worm Eradication Programme, including success stories from specific countries in implementing NTDs programmes and other health programmes (vaccine-preventable disease programmes, malaria, and some zoonotic disease programmes) for ESPEN and similar partnerships to guide future improvements in NTD elimination efforts.

Methods: Programme reports from the WHO African region on NTDs, and peer-reviewed journals and other published documents were assessed, supplemented by authors' wide experiences to gain insights into NTDs and communicable disease programme implementation across Africa. The manuscript was structured along the WHO health systems building blocks. Success stories were highlighted, lessons learned documented, and recommendations made. Contents were reviewed several times and independently by a small group. The authors' approval was secured before journal submission.

Findings and conclusions: Lessons learned, and recommendations made are beneficial to partners and countries in achieving the 2030 NTDs elimination targets in the African region and beyond. They provide pathways to expanding the structure, direction, and scope of programme implementation for greater impact.

Background: Aedes aegypti, the primary vector of Dengue fever in Burkina Faso, breeds in a variety of domestic and peri-domestic water holding containers. The influence of these water containers on the mosquitoes' ability to survive exposure to chemical insecticides remains unclear. This study investigated the insecticide susceptibility profile of Aedes aegypti in relation to larval habitat types in three districts of Ouagadougou.

Methods: Adult females reared from larvae collected in "domestic containers" and "car tires" were exposed separately to papers impregnated with deltamethrin, pirimiphos-methyl, and bendiocarb to determine their susceptibility profiles. A subsample of mosquitoes per locality and container type was screened for the F1534C, V1016I and V410L kdr mutations involved in pyrethroid resistance.

Results: Mosquito population from the three localities showed high resistance to deltamethrin and pirimiphos-methyl and moderate resistance to bendiocarbe, with mortality rates ranging from 15% to 27%, 21% to 33% and 67% to 86%, respectively. Mosquitoes from the "domestic containers" were significantly more resistant to deltamethrin than those from tires (10% vs. 22%, p < 0.002). The frequency of the 1534C mutation was also significantly higher in the "domestic containers" compared to those from tires (0.88 vs. 0.76, p = 0.013).The other mutations 1016I and 410L, were reported with an overall frequency of 0.51 and 0.36, respectively.

Conclusions: These findings suggest that larval habitat type may influence both the level and mechanisms of resistance in Aedes aegypti. This has important implications for the design of targeted vector control strategies in dengue-endemic settings.

Background: Globally, neglected tropical diseases (NTDs) affect > 1.7 billion people and remain a major cause of morbidity in fragile, resource-limited settings. Somalia, the 44th largest country worldwide, is situated in Africa and ranks among the top 20 countries with the highest number of zero-dose children. Protracted conflict, climate shocks, and displacement hinder effective surveillance and service delivery, exacerbating the prevalence of infectious diseases and active outbreaks. We assessed frontline perspectives on barriers and opportunities for neglected tropical diseases (NTDs) control and eradication in Mogadishu.

Methodology: We conducted a mixed-methods, facility-based cross-sectional study (January-June 2025) across seven hospitals (2 public, 5 private). A structured questionnaire captured sociodemographic and perceptions from 535 health workers (specialists, general practitioners, nurses, pharmacists, midwives, laboratory staff). Qualitative data comprised 15 key informant interviews (KIIs) and 6 focus group discussions (FGDs; 60 participants) with clinicians, CHWs, and managers. Quantitative data were analyzed with descriptive statistics and bivariate tests; qualitative data underwent thematic analysis.

Result: Of 535 participants, 341/535 (63.7%) were female most had 1-5 years of experience and bachelor's degrees. Training on NTDs was moderate (58.1%). Priority barriers were lack of funding (61.5%), limited infrastructure (17.4%) and low public awareness (14.2%). Perceived opportunities included improved infrastructure (38.5%; n = 206), health education (37.8%) vaccination campaigns (32.7%) joint CHW-provider training (46.0%), and mHealth for surveillance/reporting (32.9%) PPPs were viewed as essential/important (89.9%). KIIs/FGDs triangulated these findings, adding themes of stigma (especially leprosy), access barriers in IDP/conflict-affected areas, and underused PPP channels.

Conclusion: NTD progress in Somalia is constrained by financing, capacity, and coordination gaps, but integrated, feasible interventions exist: multi-year financing tied to performance; competency-based upskilling for clinicians/CHWs; standardized CHW-facility referral feedback and digitized reporting within IDSR/DHIS2; formalized PPPs for commodities/reporting/supervision; and climate-aware vector control with WASH messaging prioritized for IDP-dense, flood-prone districts.

Background: Periodontal disease substantially affects women's quality of life and shows sex-specific patterns due to physiological characteristics such as hormonal fluctuations, pregnancy, and menopause. However, most global assessments have focused on the general population and have not systematically characterized age specific burdens among women across different socio-demographic settings. This study addresses this gap by providing a life course analysis of the global, regional, and national incidence of periodontal disease in females from 1990 to 2021.

Methods: Within the Global Burden of Disease (GBD) framework, we estimated female incidence and age-standardized rates (ASR) of periodontal disease across the life course in 204 countries and territories. Socio-Demographic Index (SDI)-incorporating per-capita income, years of schooling, and fertility in women under 25-was used to stratify locations into five levels (low, low-middle, middle, high-middle, high). We examined incidence trends and burden in eight specific physiological stages (childhood, adolescent, reproductive-age, prime reproductive-age, adult, perimenopausal, menopausal and older-age), and assessed the effects of oral health resources, diagnostic rates, and hormonal fluctuations. Our study presented point estimates with 95% confidence intervals (CIs). It evaluated the changing trends in the burden of Periodontal Disease using the estimated annual percentage change (EAPC) and percentage change.

Results: Globally, the ASR differed across stages and was generally higher from the optimal reproductive age through older age. From 1990 to 2021, ASR rose steadily in childhood and adolescence, with a notable increase during the reproductive age in 2010-2014 (APC = 2.14). The optimal reproductive age showed increases in 1998-2005 and 2010-2014, adulthood and perimenopause exhibited fluctuating upward trends, while menopause and older age displayed divergent patterns. ASR-SDI associations were stage-dependent: negative correlations in childhood and adolescence, no significant association in adulthood and reproductive age, positive correlations in mid- to late-life, and SDI threshold effects (around SDI = 0.5, ASR tends to decrease; around SDI = 0.8, decelerated ASR growth).

Conclusions: Policymakers should tailor public health strategies to high-burden regions and key life stages (e.g., reproductive and mid-to-late life), expand oral-health investment for children and adolescents in low-SDI areas, and strengthen screening/interventions for mid-older women in high-SDI regions.

Introduction: Somalia, one of the world's most climate-vulnerable nations despite contributing minimally to global emissions, is facing escalating public health crises due to climate change. Rising temperatures, erratic rainfall, recurrent droughts, and floods have intensified food insecurity, disease outbreaks, and population displacement. These changes have compounded existing challenges in a fragile health system, severely affecting children, pregnant women, and internally displaced persons Internally displaced people (IDP). This scoping review aims to map the extent and scope of published evidence on the prolonged public health impacts of climate change in Somalia, identifying key health outcomes, vulnerable populations, and research and policy gaps.

Methods: Following the PRISMA-ScR guidelines, a comprehensive search was conducted in PubMed, Scopus, Web of Science, and Google Scholar, as well as gray literature from WHO, UN agencies, and Somali institutions. Studies published between 1990 and 2025 in English and addressing the intersection of climate change and public health in Somalia or the Horn of Africa were included. Data were charted and synthesized thematically.

Results: Out of 379 retrieved articles, 142 met the inclusion criteria. Key themes emerged: (1) direct health impacts of climate change, (2) indirect health impacts, (3) vulnerable populations, (4) weak health infrastructure and system readiness, and (5) historical droughts and their cumulative health impacts. Children under five, pregnant women, and displaced persons are disproportionately affected. The review highlights significant evidence gaps in mental health, health system resilience, and early warning systems.

Conclusion: This scoping review highlights the severe and multifaceted public health impacts of climate change in Somalia, the fragile healthcare infrastructure in Somalia, and a heavy reliance on external aid. This review provides a foundation for future efforts to mitigate the public health impacts of climate change and build resilience in Somalia and similar vulnerable regions.