Tropical Medicine and Health最新文献

{"title":"Sociodemographic and sex differences in the global burden of hypertensive heart disease, 1990-2021: a population-based analysis.","authors":"Fangfei Nie, Xiaorong Wang, Airong Yang, Jiaolong He, Jie Bai, Ping Yan, Xiaozhou Wang","doi":"10.1186/s41182-025-00791-9","DOIUrl":"10.1186/s41182-025-00791-9","url":null,"abstract":"<p><strong>Background: </strong>Hypertensive heart disease (HHD) is a major global contributor to cardiovascular-related disability. Although its burden has been previously described, detailed analyses of long-term disability trends by sociodemographic level and sex remain scarce. This study aimed to systematically assess global and subgroup-specific patterns in HHD-related disability-adjusted life years (DALYs) from 1990 to 2021.</p><p><strong>Methods: </strong>Data from the Global Burden of Disease Study 2021 were used to evaluate age-standardized DALY rates for HHD across five socio-demographic index (SDI) levels and by sex from 1990 to 2021. Temporal trends were assessed using Joinpoint regression with estimated annual percent change (EAPC). Future rates through 2036 were projected using Bayesian age-period-cohort models. Decomposition analysis quantified contributions of population growth, aging, and epidemiologic changes, and risk-attributable DALYs were estimated for five modifiable exposures.</p><p><strong>Results: </strong>Globally, DALYs from HHD increased from 15.47 to 25.46 million (+ 64.6%) between 1990 and 2021, while the age-standardized DALY rate declined from 406.51 to 301.58 per 100,000 population (EAPC - 0.96; 95% CI - 0.98 to - 0.93). DALY counts rose and age-standardized DALY rate declined across all SDI levels, with the greatest reduction in middle-SDI regions (EAPC - 1.89; 95% CI - 2.17 to - 1.60) and notable decreases in high-middle SDI regions (EAPC - 1.06; 95% CI -1.68 to - 0.43). Rates in females remained consistently higher than in males, with projections suggesting persistent disparities through 2036. Decomposition analysis indicated that population aging and growth were the main contributors to DALY increases, partially offset by epidemiological improvements. High systolic blood pressure (- 100%) and elevated body mass index (- 50%) were the leading modifiable risk factors across SDI levels.</p><p><strong>Conclusions: </strong>Despite declines in age-standardized DALY rate, the absolute HHD burden continues to grow, particularly among women and in low-SDI regions. Targeted, equity-focused cardiovascular strategies are urgently needed to address these persistent disparities.</p>","PeriodicalId":23311,"journal":{"name":"Tropical Medicine and Health","volume":"53 1","pages":"108"},"PeriodicalIF":3.5,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12351887/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144856443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of fructo-oligosaccharides on genitourinary tract infections and birth outcomes in pregnant women: a randomized controlled trial in Bangladesh.","authors":"Shamima Sultana, Yukiko Wagatsuma, Rumana Sharmin, Dilruba Ahmed, Arif Hasan Chowdhury, Ahshanul Haque, Tahmeed Ahmed, Harald Brüssow, Shafiqul Alam Sarker","doi":"10.1186/s41182-025-00788-4","DOIUrl":"10.1186/s41182-025-00788-4","url":null,"abstract":"<p><strong>Background: </strong>Genitourinary tract infections, including bacterial vaginosis, which is characterized by the loss of Lactobacillus (LAB) in the vaginal microbiota, is a risk factor for low birth weight. The aim of this study was to examine the effects of fructo-oligosaccharide (FOS) supplementation on the incidence of genitourinary tract infections in pregnant women and the birth weights of newborns in Bangladesh.</p><p><strong>Methods: </strong>A randomized, double-blinded, placebo-controlled study was conducted in Dhaka, Bangladesh. Women in early pregnancy were randomized to the FOS or placebo groups (105 women per group), and supplements were provided daily until delivery. Stool samples were collected from women at baseline and at 24 and 36 weeks of gestation and from infants at birth for the analysis of LAB and Bifidobacterium by PCR. Vaginal swabs to test for bacterial vaginosis were collected at 18 and 30 weeks of gestation. Anthropometric measurements were taken at birth, and the newborns were followed up for 6 months.</p><p><strong>Results: </strong>Of the 210 pregnant women, 8 had abortions, 5 refused the study product, 31 migrated, 4 had infants who were stillborn, and the neonate of 1 woman died early. The mean (SD) birth weight was 2799 (381) grams; 27 (17.0%) newborns had low birth weight (15.6% in the FOS group and 19.5% in the placebo group). Birth weight did not differ between the groups after adjusting for gestational week at birth and maternal early pregnancy BMI. Bacterial vaginoses were observed in 4.3% of women in the FOS group and 3.1% of women in the placebo group and were not statistically different between the groups. LAB colonization rates in stools of pregnant women at 24 and 36 gestational weeks did not differ between the groups. However, LAB colonization rate was higher in stools of infants in the FOS group than in those in the placebo group (68.8% in the FOS group and 51.2% in the placebo group, p = 0.024). This difference remained significant after adjusting for maternal age and LAB colonization at baseline (adjusted risk ratio (95% CI) = 1.45 (1.12-1.88), p = 0.005). The rate of Bifidobacterium colonization in the stools of infants did not differ between the groups.</p><p><strong>Conclusions: </strong>FOS supplementation did not affect bacterial vaginosis incidence in pregnant women or infant birth weight. A higher rate of Lactobacillus in the stool samples of infants whose mothers received FOS was observed. Further studies are needed to confirm these findings with a large sample size.</p><p><strong>Trial registration: </strong>This study was registered at Clinicaltrials.gov (NCT02127225).</p>","PeriodicalId":23311,"journal":{"name":"Tropical Medicine and Health","volume":"53 1","pages":"106"},"PeriodicalIF":3.5,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12344985/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144849183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First report of a Plasmodium malariae SSU rRNA gene variant in Africa associated with reduced amplification by nested PCR.","authors":"Maki Goto, Kei Yamamoto, Kanako Komaki-Yasuda, Shigeyuki Kano, Norio Ohmagari","doi":"10.1186/s41182-025-00787-5","DOIUrl":"10.1186/s41182-025-00787-5","url":null,"abstract":"<p><strong>Background: </strong>Nested polymerase chain reaction (PCR) targeting the small subunit ribosomal ribonucleic acid (SSU rRNA, 18S rRNA) region is widely used to differentiate Plasmodium species. We identified a variant of the Plasmodium malariae SSU rRNA gene that suggests nested PCR may fail to detect P. malariae strains with unknown mutations.</p><p><strong>Case presentation: </strong>A 56-year-old Japanese man developed a fever 2 months after returning from a 2-month stay in Sierra Leone. Quartan malaria was suspected based on blood smear findings, and nested PCR confirmed P. malariae infection. However, the secondary PCR band obtained using P. malariae-specific primers was fainter than the primary PCR band amplified with universal primers-a reversal of the typical pattern. Sequence analysis revealed a four-base deletion in the SSU rRNA gene within the primer-binding site of the species-specific reverse primer used in the secondary PCR, suggesting that mutations in this region may partially impair amplification and hinder species identification. Cytochrome b gene sequencing confirmed 100% identity with P. malariae.</p><p><strong>Conclusions: </strong>These findings underscore the need for continued molecular surveillance and sequence-based validation to ensure accurate diagnosis of Plasmodium infections, particularly in regions where genetic variants and zoonotic strains are emerging.</p>","PeriodicalId":23311,"journal":{"name":"Tropical Medicine and Health","volume":"53 1","pages":"104"},"PeriodicalIF":3.5,"publicationDate":"2025-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12323105/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144785411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Leveraging geographic information system for dengue surveillance: a scoping review.","authors":"Prathiksha Prakash Nayak, Jagadeesha Pai B, Sreejith Govindan","doi":"10.1186/s41182-025-00783-9","DOIUrl":"10.1186/s41182-025-00783-9","url":null,"abstract":"<p><strong>Background: </strong>Vector-borne diseases caused by Aedes mosquitoes remain a major public health concern across tropical and subtropical regions. Geographic Information Systems (GIS) have become integral in surveillance by enabling spatial analysis, risk mapping, and predictive modelling. This scoping review explores how GIS has been applied in surveillance studies and identifies its potential applications, key variables, modelling approaches, and challenges.</p><p><strong>Methods: </strong>This scoping review was conducted following PRISMA-ScR guidelines and was structured using a search strategy to identify relevant peer-reviewed articles published between 2015 and 2024 across databases like PubMed, Scopus, ScienceDirect, and Google Scholar. A total of 64 studies were selected and charted based on geographic focus, GIS applications, modelling techniques, spatial methods, and key variables.</p><p><strong>Results: </strong>A notable concentration of studies was found in South and Southeast Asia, reflecting the high disease burden and research activity in these regions. ArcGIS and QGIS were the most frequently used platforms in dengue surveillance around the globe. Risk mapping and hotspot detection were the most frequent targeted applications (n = 26), followed by vector control and monitoring (n = 23). Environmental and climatic variables were commonly analysed, including temperature, rainfall, humidity, and Normalised Difference Vegetation Index. Common analytical methods included regression-based spatial models and, increasingly, machine learning techniques along with GIS. Emerging trends include integrating machine learning models, remote sensing data, and mobile GIS for real-time monitoring and early warning systems.</p><p><strong>Conclusions: </strong>GIS has evolved from a mapping tool into a multidimensional decision-support system in disease surveillance. Its integration with environmental, climatic, and demographic data enables proactive outbreak management and targeted interventions. Future research should leverage Artificial Intelligence, machine learning, the Internet of Things, participatory GIS, and interdisciplinary data to enhance surveillance prediction and public health response. Strengthening collaborative data-sharing frameworks and incorporating machine-learning approaches could further improve the effectiveness of GIS-driven surveillance programs.</p>","PeriodicalId":23311,"journal":{"name":"Tropical Medicine and Health","volume":"53 1","pages":"102"},"PeriodicalIF":3.5,"publicationDate":"2025-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12320306/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144785412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Malaria and determinants of health: a scoping review of malaria vulnerabilities in Southeast Asia.","authors":"Shahrul Azhar Md Hanif, Mohd Rohaizat Hassan, Nazarudin Safian, Rosnah Sutan, Alabed Ali A Alabed, Muhammad Ridzwan Rafi'i, Siti Najiha Md Asari, Nurul Athirah Naserrudin, Rahmat Dapari","doi":"10.1186/s41182-025-00784-8","DOIUrl":"10.1186/s41182-025-00784-8","url":null,"abstract":"<p><strong>Introduction: </strong>Malaria continues to pose a considerable public health challenge in Southeast Asia, necessitating control efforts that consider region-specific vulnerabilities. Although global risk factors are well-documented, the interplay of social determinants of health in shaping malaria vulnerability within SEA populations is less thoroughly explored.</p><p><strong>Objective: </strong>This scoping review aims to determine elements influencing vulnerabilities towards malaria in SEA populations. In addition, this study seeks to explore how various social determinants of health contribute to the increased malaria vulnerabilities in this region.</p><p><strong>Method: </strong>This review adhered to the PRISMA-ScR guidelines. A systematic literature search was performed in PubMed, Scopus, and Web of Science from October to November 2024, focusing on peer-reviewed, open-access quantitative studies published from 2014 to 2024. Studies that addressed the risk or vulnerability of malaria in SEA populations were included. Multiple reviewers independently conducted screening, data charting, and thematic synthesis.</p><p><strong>Result: </strong>Twenty-two studies met the inclusion criteria, encompassing various malaria-endemic settings in SEA, including cross-border regions and migrant populations. The findings were synthesized using a social determinants of health lens, resulting in five thematic domains: biological influences, demographic and socioeconomic parameters, built and lived environments, behaviour and practices, and access to healthcare services and information.</p><p><strong>Conclusion: </strong>The vulnerability of SEA population to malaria is multifaceted and deeply entrenched in a web of complex, interrelated factors. Effective control requires region-specific, multi-sectoral strategies that address these vulnerabilities through targeted interventions, strengthened health systems, and equitable public health policies.</p>","PeriodicalId":23311,"journal":{"name":"Tropical Medicine and Health","volume":"53 1","pages":"105"},"PeriodicalIF":3.5,"publicationDate":"2025-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12323273/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144785413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative performance of Kato-Katz, POC-CCA and real-time PCR in detecting Schistosoma mansoni infection at different endemicity settings in northwest Ethiopia: a cross-sectional study.","authors":"Getaneh Alemu, Endalkachew Nibret, Abaineh Munshea, Melaku Anegagrie, María Flores-Chávez, Tadesse Hailu, Arancha Amor","doi":"10.1186/s41182-025-00777-7","DOIUrl":"10.1186/s41182-025-00777-7","url":null,"abstract":"<p><strong>Background: </strong>Effective detection of Schistosoma mansoni is crucial for the control and management of the infection. This study aimed to evaluate the field performance of three diagnostic methods-point-of-care circulating cathodic antigen (POC-CCA) assay, Kato-Katz (KK) technique, and real-time polymerase chain reaction (RT-PCR)-for detecting S. mansoni infection in different transmission settings across northwest Ethiopia.</p><p><strong>Methods: </strong>From February to June 2023, a cross-sectional study was conducted in the Amhara Regional State of Ethiopia, involving 1192 randomly selected participants. Stool samples were analyzed using the KK technique and RT-PCR, while urine samples were tested using the POC-CCA cassette. The performance of POC-CCA and RT-PCR was evaluated against a KK reference standard across varying transmission areas. In addition, diagnostic accuracy for all three methods was assessed using latent class analysis (LCA) with Mplus software. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and kappa statistics were calculated using the Simple Interactive Statistical Analysis (SISA) online tool.</p><p><strong>Results: </strong>The KK method showed the lowest prevalence (33.4%) and demonstrated reduced sensitivity, particularly in low (54.6%) and moderate (67.0%) transmission areas, though it performed better (88.6%) in high-endemic settings compared to LCA reference. In contrast, the POC-CCA test showed higher prevalence (53.5%) and consistently high sensitivity (93.4-100%) across transmission settings, although its specificity declined in low (86.0%) and moderate (78.9%) endemic areas against LCA. Compared to the KK gold standard, POC-CCA had high sensitivity (93.5%) and NPV (95.3%) but lower specificity (62.5%) and moderate agreement (kappa = 0.52). RT-PCR exhibited strong diagnostic performance, with high sensitivity against both KK (93.5%) and LCA (97.2%) but declining specificity as endemicity increased (84.2% in low, 79.4% in moderate and 28.0% in high-endemic areas), and showed substantial agreement with LCA (kappa = 0.75).</p><p><strong>Conclusions: </strong>The KK demonstrates low sensitivity, particularly in low-transmission settings. Both the POC-CCA test and RT-PCR show good performance for detecting S. mansoni infection. However, due to its complexity and resource requirements, RT-PCR is not feasible for routine field use. Therefore, we recommend the adoption of the POC-CCA test in Ethiopia's SCH control and elimination programs.</p>","PeriodicalId":23311,"journal":{"name":"Tropical Medicine and Health","volume":"53 1","pages":"103"},"PeriodicalIF":3.5,"publicationDate":"2025-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12323140/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144785410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Screening for visceral leishmaniasis in humans and animals in Laos.","authors":"Tamalee Roberts, Anousone Douangnouvong, Matthew T Robinson, Koukeo Phommasone, Saykham Phaxayaseng, Valy Keoluangkhot, Khamsing Vongphayloth, Aphaphone Adsamoud, Othila Rasphone, Leeyounjera Yang, Phonelevanh Phoumin, Manivone Simmalavong, Peter Christensen, Tom Hughes, Adisone Temmerath, Alex Inthavong, Phoummavanh Inthapanya, Sivone Punyasith, Phouvong Phommachanh, Wattana Theppangna, Syseng Khounsy, Susath Vongphachanh, Stuart D Blacksell, Paul N Newton, Mayfong Mayxay, Elizabeth A Ashley","doi":"10.1186/s41182-025-00782-w","DOIUrl":"10.1186/s41182-025-00782-w","url":null,"abstract":"<p><strong>Background: </strong>Visceral leishmaniasis (VL) is a vector-borne protozoan disease with a global distribution, with higher rates of infection associated with HIV. Zoonotic species of Leishmania have also been reported infecting domestic animals. Reports of VL are increasing in Southeast Asia, with over 200 cases reported in Thailand since the first autochthonous case in 1999, and recently the first patients have been reported from Vietnam and Cambodia. However, no cases of VL have been reported from Lao PDR (Laos) and clinical awareness of the disease is limited. This study aimed to investigate whether Leishmania is circulating in Laos by screening people living with HIV, stored samples from unselected patients with fever, and ruminants taken to abattoirs.</p><p><strong>Methods: </strong>People living with HIV from two specialist units in Vientiane Capital had EDTA blood taken and DNA extracted and tested for Leishmania by nested-PCR. Stored serum samples from patients presenting to Mahosot Hospital with fever and without known HIV infection, as well as serum from goats, cows and buffalo taken to abattoirs in four provinces in Laos were tested for Leishmania using the InBios Kalazar Detect Rapid Test.</p><p><strong>Results: </strong>There were 1015 people living with HIV tested between 2021 and 2024 for Leishmania by nested-PCR, all of whom were negative. Of 511 human serum samples collected between 2005 and 2023, two (0.4%) tested positive by rapid test. These samples were identified as coming from the same patient, with samples taken 10 months apart. There were 5/159 (3.1%) ruminant serum samples positive by rapid test with 3/45 (6.7%) buffalo positive, 2/47 (4.3%) goat positive and 0/67 cows positive.</p><p><strong>Conclusions: </strong>This study suggests Leishmania may be circulating in Laos with undetected cases. Further investigation is needed to confirm the findings, determine at-risk populations and increase clinical awareness of the disease. This study expands on the current regional knowledge on leishmaniasis and shows the need for further epidemiological studies.</p>","PeriodicalId":23311,"journal":{"name":"Tropical Medicine and Health","volume":"53 1","pages":"101"},"PeriodicalIF":3.5,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12315420/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144765590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of the physicochemical characteristics of mosquito breeding sites in domestic environments on the distributions of Anopheles, Aedes and Culex mosquitoes in Benin.","authors":"Isidore Hoyochi, Germain Gil Padonou, Tatchémè Filémon Tokponnon, Alphonse Keller Konkon, David Mahouton Zoungbédji, Albert Sourou Salako, Brice Dangnon, A Virgile Onésime Akowanou, Luc Olivier Sintondji, Edmond Sossoukpe, Lamine Baba-Moussa, Martin Codjo Akogbéto","doi":"10.1186/s41182-025-00786-6","DOIUrl":"10.1186/s41182-025-00786-6","url":null,"abstract":"<p><strong>Background: </strong>Malaria, dengue and lymphatic filariasis are diseases transmitted by Anopheles, Aedes and Culex mosquitoes, respectively. These mosquitoes have evolved and adapted to environmental conditions and human lifestyles, providing them with a variety of breeding sites. This study aimed to determine the influence of the physicochemical characteristics of breeding sites on the distribution of Anopheles, Aedes and Culex mosquitoes in Benin.</p><p><strong>Methods: </strong>The collections took place from January to November 2025 and lasted 9 months. Mosquito larvae were collected from 11 municipalities in Benin. Physicochemical parameters such as pH, temperature, salinity, total dissolved solids, conductivity, dissolved oxygen and turbidity were measured in situ during larval sampling. Variations among the physicochemical parameters were assessed via Chi-square multiple comparisons of proportions and the least significant difference (LSD) test following analysis of variance (ANOVA). Correlations between physicochemical variables were analyzed via principal component analysis (PCA).</p><p><strong>Results: </strong>The results revealed that domestic containers and tires were the most common indoor and outdoor breeding sites for human dwellings, respectively. The pH levels slightly varied across the different breeding sites but generally remained nearly neutral. The temperatures were relatively consistent among the habitats, averaging approximately 30 °C. Salinity levels were close to zero at most Aedes and Anopheles breeding sites, whereas Culex larvae were commonly associated with sites with salinity values close to one. The total dissolved solids and conductivity varied considerably among the sites. Dissolved oxygen was positively correlated with the presence of Anopheles larvae. Both Aedes and Anopheles are typically found in habitats with low turbidity, whereas Culex larvae are associated with highly turbid environments, with turbidity ranging from 10 to 858 NTU. Principal component analysis revealed strong positive correlations between conductivity, salinity, and TDS; weak correlations between turbidity and temperature; and negative correlations between dissolved oxygen, conductivity, and salinity.</p><p><strong>Conclusion: </strong>This study highlights the importance of the physicochemical properties of breeding sites in the distribution of primary vector mosquito species. The prevalence of domestic containers and tires as breeding sites underscores the necessity of targeted interventions in these habitats, both indoors and outdoors of human dwellings.</p>","PeriodicalId":23311,"journal":{"name":"Tropical Medicine and Health","volume":"53 1","pages":"100"},"PeriodicalIF":3.5,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12308970/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144754394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The morphology, genetic structure, and haplotype distribution of the invasive freshwater snails Biomphalaria straminea and Physa acuta in Guangdong, China.","authors":"Ping He, Yunyi Hu, Jehangir Khan, Yan Huang, Zhanhong Yuan, Benjamin Sanogo, Du Gao, Jun Liu, De Wu, Jingdiao Chen, Zhongdao Wu, Song Liang, Xi Sun, Datao Lin","doi":"10.1186/s41182-025-00780-y","DOIUrl":"10.1186/s41182-025-00780-y","url":null,"abstract":"<p><strong>Background: </strong>Biomphalaria and Physa (order Gastropoda) serve as vectors and reservoirs for infectious agents that affect both humans and animals. This study provides updated insights into the epidemiology, morphology, phylogeny, and haplotype diversity of Biomphalaria and Physa snails in Guangdong Province, southern China.</p><p><strong>Methods: </strong>Field surveys were conducted across Guangdong Province from 2016 to 2023. Morphological observations included assessment of snail shape, shell height, and aperture width. Molecular analysis targeted several genes, including Cytochrome c oxidase subunit 1 (COI), internal transcribed spacer (ITS), 18S rRNA, 16S rRNA, and 28S rRNA. Evolutionary trees were constructed with neighbor-joining and maximum likelihood methods. Haplotype networks were generated from COI sequences collected from multiple geographic locations.</p><p><strong>Results: </strong>Physa acuta was detected in 92% of surveyed sites, showing broad distribution and notable mitochondrial diversity (15 haplotypes). The dominant haplotype (Hap_3) was shared with sequences from Chile and the Netherlands. In contrast, Biomphalaria straminea was found at 62% of sites and displayed limited genetic variation (2 haplotypes), despite visible morphological dimorphism (red/black forms). Phylogenetic analysis exhibited minimal differences in 16S rRNA and COI gene sequences among turret snail strains, with B. straminea clustering closely to South American lineages. Morphometric analyses revealed significant size differences among strains, for example, Shuanglong B. straminea had a shell width of 8.74 ± 0.26 mm, whereas Zengcheng P. acuta exhibited 11.07 ± 0.90 mm. In contrast, analysis of 28S and 18S rRNA confirmed species boundaries but lacked at the intraspecific level.</p><p><strong>Conclusions: </strong>Our analysis of multiple target genes confirms that mitochondrial markers (COI and 16S rRNA) are effective for studying the evolutionary dynamics of freshwater invasive snails. Physa acuta exhibits a widespread distribution and notable genetic diversity across Guangdong, while B. straminea shows limited genetic variation, suggesting strong genetic conservation within the species.</p>","PeriodicalId":23311,"journal":{"name":"Tropical Medicine and Health","volume":"53 1","pages":"98"},"PeriodicalIF":3.5,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12302756/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144733399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intra-familial transmission of Hepatitis B virus in a peri-urban community from the Democratic Republic of the Congo.","authors":"Florence Cindibu Kalonji, Yu Nakagama, Evariste Tshibangu-Kabamba, Nadine Kayiba Kalenda, Shun Nakagama, Sachie Nakagama, Pathy Kamanga Nkolongo, Nestor Kalala-Tshituka, Alphonse Lufuluabu Mpemba, Faustin Ndjibu Mpoji, André Kabongu Kalala, Benjamin Muamba Mpoyi, Dieudonné Mumba Ngoyi, Natsuko Kaku, Yusuke Shimakawa, Ghislain Tumba Disashi, Yasutoshi Kido","doi":"10.1186/s41182-025-00781-x","DOIUrl":"10.1186/s41182-025-00781-x","url":null,"abstract":"<p><strong>Background: </strong>Despite global elimination targets set for 2030, Hepatitis B virus (HBV) infection remains a major public health challenge in low-income countries, including the Democratic Republic of Congo (DRC). Limited evidence on the regional transmission pathways precludes progress towards HBV elimination. This study aimed to assess the prevalence, molecular characteristics, and transmission dynamics of HBV in the Lukelenge health district, a peri-urban area in central DRC.</p><p><strong>Methods: </strong>We employed a two-tiered recruitment strategy: community member volunteers were enrolled during the first phase, and upon notification of HBV positivity in an index case, family contacts were subsequently recruited in the second phase. Participants were screened for hepatitis B surface antigen (HBsAg), followed by PCR amplification of HBV DNA and sequencing. Genotyping and phylogenetic analysis of preS/S sequences were performed to explore regional HBV diversity and transmission patterns.</p><p><strong>Results: </strong>A total of 751 participants from 677 households were included. The overall HBsAg prevalence was 3.8% [95% CI 2.6-5.7], with the highest rate (10.1% [95% CI 4.9-18.2]) found in children aged 5 years and younger. All 42 HBV isolates belonged to genotype E, with 97.6% sharing the ayw4 serotype. Mutations with relevancy to immune escape were detected in 9.5% of strains, while those possibly linked to antiviral resistance were found in 4.7%. Maximum likelihood phylogenetic analysis showed intra-familial clustering of preS/S sequences, suggesting that parent-to-child transmission was the most frequent mode of HBV spread in the study population.</p><p><strong>Conclusions: </strong>HBV in Lukelenge shows intermediate endemicity, especially affecting young children. Intra-familial transmission is revealed to be predominant, likely involving both vertical and horizontal pathways. Family-targeted interventions, including maternal screening and universal birth-dose vaccination, should be prioritized to eliminate HBV in this region.</p>","PeriodicalId":23311,"journal":{"name":"Tropical Medicine and Health","volume":"53 1","pages":"99"},"PeriodicalIF":3.5,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12302796/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144733398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}