Acta tropica最新文献

{"title":"Hemoplasmas in opossums (Didelphis virginiana) from southeastern Mexico.","authors":"Gerardo G Ballados-González, Mariemma G Escorcia-Quintana, Alejandra Chong-Guzmán, Janette Gamboa-Prieto, Adair Caro-Macin, José M Martínez-Hernández, Estefania Grostieta, Anabel Cruz-Romero, Mariel Aguilar-Domínguez, Rafael F C Vieira, Carlos D Pérez-Brígido, Juan M Pech-Canché, Blanca E Raya-Cruz, Arturo Serrano-Solís, Celina Naval-Ávila, Víctor Sánchez-Cordero, Ángel Rodríguez-Moreno, Pablo Arenas, Guillermo Gil-Alarcón, Marco Torres-Castro, Enrique Reyes-Novelo, Jose L Bravo-Ramos, Claudia I Muñoz García, Emilio Rendón-Franco, Sokani Sánchez-Montes","doi":"10.1016/j.actatropica.2025.107734","DOIUrl":"https://doi.org/10.1016/j.actatropica.2025.107734","url":null,"abstract":"<p><p>Hemoplasmas (hemotropic mycoplasmas) are a neglected group of bacteria that infect the erythrocytes of a wide range of mammals, including members of the order Didelphimorphia. At the continental level, two hemoplasma species are recognized infecting four Didelphis species: 'Candidatus Mycoplasma haematodidelphidis' and 'Candidatus Mycoplasma haematoalbiventris' in the United States and Brazil. Therefore, this study aimed to determine the prevalence and genetic diversity of hemoplasmas species in 120 Virginia opossums (Didelphis virginiana) from Veracruz and Tabasco, Mexico. A total of 20/102 (19.61%, 95% CI: 13.07-28.36%) animals tested positive for hemoplasmas. The sequences generated in this study exhibited a similarity range of 98.19-100% among themselves (872/888-888/888 bp). Comparisons with available reference sequences revealed 97.97-99.77% similarity (868/886-886/888 bp) to the only known sequence of 'Candidatus Mycoplasma haematodidelphidis' from the USA (GenBank accession number: AF178676). Additionally, we identified nine novel haplotypes. This study provides the first record of hemoplasmas in Didelphis species from Mexico and the first report of 'Ca. M. haematodidelphidis in Mexican marsupials, thereby expanding the inventory of the hemoplasmas diversity associated with marsupials.</p>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":" ","pages":"107734"},"PeriodicalIF":2.1,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144599092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Urinary Biomarkers and Haematuria as Indicators of Urogenital Schistosomiasis: A Systematic Review and Meta-Analysis.","authors":"Maryline Vere, Wilma Ten Ham-Baloyi, Opeoluwa Oyedele, Takafira Mduluza, Paula E Melariri","doi":"10.1016/j.actatropica.2025.107716","DOIUrl":"https://doi.org/10.1016/j.actatropica.2025.107716","url":null,"abstract":"<p><strong>Background: </strong>Schistosomiasis, is a parasitic infection that leads to chronic illness and socioeconomic challenges in tropical regions. Adult Schistosoma (S.) haematobium worms inhabit the bladder's venous plexus and produce eggs that cause tissue inflammation and systemic pathologies, detectable as urinary biomarkers in bodily fluids like urine, blood, and serum. Urinalysis offers a rapid, cost-effective, non-invasive assessment of schistosomiasis-related urinary biomarkers.</p><p><strong>Objectives: </strong>This systematic review aimed to identify urinary biomarkers indicative of S. haematobium infections and assess their diagnostic relevance.</p><p><strong>Methods: </strong>A systematic search was conducted in databases including PubMed, EbscoHost, and Google Scholar to find studies on urogenital schistosomiasis urinary biomarkers detected by point-of-care dipsticks in sub-Saharan Africa. From 699 screened studies, 19 met the inclusion criteria. These studies focused on point-of-care dipstick use for all age groups, excluding those using laboratory-based methods. The Joana Briggs quality assesment tool was used to evaluate the selected articles, and a detailed narrative summary was created. A meta-analysis assessed study variability.</p><p><strong>Results: </strong>The analysis identified haematuria and proteinuria as key urinary markers for diagnosing urinary schistosomiasis infections. The meta-analysis found a statistically significant pooled prevalence for haematuria, proteinuria, leukocyturia, nitrates, bilirubin, and urobilinogen. Significant heterogeneity was observed in studies measuring haematuria, proteinuria, leukocyturia, and nitrates (over 80%), with lower but still non-significant heterogeneity for nitrates (39.3%).</p><p><strong>Conclusion: </strong>Haematuria, proteinuria and leukocyturia are indicators of urogenital schistosomiais morbidity; nonetheless, further investigation is necessary to measure metabolite concentrations directly associated with schistosomiasis morbidity for improved diagnostic precision.</p>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":" ","pages":"107716"},"PeriodicalIF":2.1,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144599103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phylogeographic investigation of tick-borne pathogens in host-seeking Dermacentor marginatus in Anatolia: Significant correlation between population genetic structure and SFG rickettsiae","authors":"Ömer Orkun ,&nbsp;Maide Nur Gündoğdu ,&nbsp;Tuğba Özdemir ,&nbsp;Mesut Yiğit ,&nbsp;Eneshan Sarıkaya ,&nbsp;Anıl Yılmaz ,&nbsp;Barış Yıldız ,&nbsp;Hilal Bedir ,&nbsp;Ahmet Deniz ,&nbsp;Zati Vatansever","doi":"10.1016/j.actatropica.2025.107730","DOIUrl":"10.1016/j.actatropica.2025.107730","url":null,"abstract":"<div><div>Characterizing the population structure of vector ticks and their associated microorganisms in natural foci is essential for understanding of the ecology of tick-borne disease (TBD) and developing effective control strategies. <em>Dermacentor marginatus</em> is an important vector species in the Palearctic realm, yet its vectorial role remains poorly defined, particularly due to the lack of studies integrating population genetics with pathogen data. In this study, we performed a phylogeographic analysis of tick-borne pathogens (TBPs) in host-seeking <em>D. marginatus</em> from natural foci across Anatolia, integrating these data with the population genetic information from the same specimens. A total of 696 ticks from 151 locations were screened. PCR and sequencing revealed that 58.8 % (409/696) of ticks carried at least one causative agent, including spotted fever group (SFG) rickettsiae (<em>Rickettsia slovaca</em> and <em>R. raoultii</em>), <em>Coxiella burnetii, Francisella tularensis</em> subsp. <em>holarctica, Francisella</em>-like endosymbionts, <em>Babesia</em> spp. (<em>B. occultans, B. vulpes</em>, and <em>B. bigemina</em>), <em>Theileria ovis</em>, and <em>Hepatozoon</em> spp. (<em>H. canis</em> and two unidentified species). Our findings revealed distinct phylogeographic patterns of SFG rickettsiae between Central and Northeastern populations, providing the first evidence of a population-level evolutionary association between <em>D. marginatus</em> and <em>R. slovaca/raoultii</em>. Previously unrecognized natural foci of <em>C. burnetii</em> and <em>F. tularensis</em> subsp. <em>holarctica</em> associated with <em>D. marginatus</em> were also identified. Several novel tick-pathogen associations were documented. These results indicate a high prevalence of human-pathogenic agents in <em>D. marginatus</em> populations in Anatolia suggest that population genetic structure may influence silent tick-pathogen interactions. By integrating population genetics with pathogen screening, this study offers new insights into the ecology and evolutionary dynamics of <em>D. marginatus</em> and associated TBPs.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"268 ","pages":"Article 107730"},"PeriodicalIF":2.1,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144566984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The current status and predicted climate-driven range expansion of Rhipicephalus microplus in northern Vietnam.","authors":"Duan Pham Ngoc, Thanh Dao Thi Ha, San Nguyen Ngoc, Minh Pham Ngoc, Ngoc Duong Nhu, Róbert Farkas, Sirinya Teeraananchai, Sándor Hornok","doi":"10.1016/j.actatropica.2025.107732","DOIUrl":"https://doi.org/10.1016/j.actatropica.2025.107732","url":null,"abstract":"<p><p>Rhipicephalus microplus is a major ectoparasite of cattle, significantly impacting animal health and livestock productivity in tropical and subtropical regions. This study investigated the current status and predicted the future distribution of R. microplus in northern Vietnam under climate change scenarios. Field surveys were conducted across 25 provinces from 2022 to 2024, collecting data on tick infestation by province, season and host species. Statistical analyses were performed by multivariable logistic regression. To forecast future distribution, the MaxEnt model was employed under RCP-4.5 and RCP-8.5 climate scenarios for the years 2050 and 2070. The presence of R. microplus was confirmed in 80.6% of survey sites, with a higher prevalence observed during the summer and autumn seasons. Statistical analysis revealed that season and host species were significant predictors of tick presence. The MaxEnt model projected an expansion of suitable habitats for R. microplus toward higher latitudes and altitudes, especially under the high-emission scenario (RCP-8.5). This is the first study to combine field-based prevalence data with climate-driven MaxEnt modeling for R. microplus in Vietnam. The findings highlight the potential impact of climate change on tick ecology and underscore the need for adaptive control strategies to mitigate the spread of tick-borne diseases in northern Vietnam.</p>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":" ","pages":"107732"},"PeriodicalIF":2.1,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144566985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of artificial cold selection on the behaviour and immune response of the major malaria vector Anopheles arabiensis (Diptera: Culicidae)","authors":"Nashrin F. Patel ,&nbsp;Shüné V. Oliver","doi":"10.1016/j.actatropica.2025.107731","DOIUrl":"10.1016/j.actatropica.2025.107731","url":null,"abstract":"<div><div>The physiological response of mosquitoes to cold is poorly understood, particularly for <em>Anopheles</em> mosquitoes, where overwintering is rarer than in <em>Aedes</em> and <em>Culex</em>. The effect of cold selection was examined in two laboratory strains of the major malaria vector <em>An. arabiensis</em> that differ in insecticide resistant phenotypes. This is due to previous studies that demonstrated an increased tolerance for high temperatures in insecticide resistant <em>An. arabiensis</em>. The insecticide unselected SENN strain and the insecticide-resistant SENN-DDT strain were reared at decreasing fluctuating temperatures for three generations until adults emerged at 18°C. Adults from this generation was exposed to 18°C and 25°C and their longevity compared to unselected counterparts. Furthermore, their landing and biting behaviour at 20 and 25°C were assessed. Finally, the expression of the antimicrobial peptides Attacin, Cecropin, Defensin and Gambicin was assessed. The cold selection had variable effects on the two strains. Cold selection significantly increased adult female longevity at 18°C in SENN-DDT but not SENN. By contrast, cold selection increased landing at 20°C in SENN but not SENN-DDT. However, it decreased biting success at 20°C in both strains. Cold treatment increased Attacin and cecropin expression in both strains but had no effect on Defensin and Gambicin expression. This study suggests that winter survival in <em>An. arabiensis</em> is associated with increased longevity and reduced feeding success. Increased antimicrobial peptide activity was generally observed under cold conditions. These factors combined may contribute to reduced transmission of <em>Plasmodium</em> under winter conditions, over and above the low population density.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"268 ","pages":"Article 107731"},"PeriodicalIF":2.1,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144557225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Innovative trap approaches for studying Phlebotomus papatasi: Emphasizing color and position","authors":"Saideh Yousefi ,&nbsp;Madineh Abbasi ,&nbsp;Alireza Sanei‑Dehkordi ,&nbsp;Kourosh Azizi ,&nbsp;Saeed Shahabi ,&nbsp;Zahra Gheibi ,&nbsp;Sorna Dabaghmanesh ,&nbsp;Mozaffar Vahedi ,&nbsp;Nima Danaei ,&nbsp;Azim Paksa","doi":"10.1016/j.actatropica.2025.107727","DOIUrl":"10.1016/j.actatropica.2025.107727","url":null,"abstract":"<div><h3>Background</h3><div>Phlebotomine sand flies are important vectors of leishmaniasis globally. Sticky traps are commonly used tools for studying the biology and ecology of <em>Phlebotomus papatasi</em> sand flies. This study aimed to evaluate the effectiveness of colored sticky traps placed under different conditions for capturing <em>P. papatasi</em> in southern Iran.</div></div><div><h3>Materials and Methods</h3><div>Sand fly populations in Shiraz County, Fars Province, were sampled monthly using sticky traps of seven different colors positioned horizontally and vertically. Non-parametric statistical tests, including the Kruskal-Wallis test, Mann-Whitney <em>U test</em>, Poisson Regression model, Chi-square test, and Wilcoxon signed-rank test, were used to compare the median numbers of sand fly specimens attracted to differently colored sticky traps under various conditions and orientations.</div></div><div><h3>Results</h3><div>A total of 2619 sand flies, including four species, were collected, with <em>P. papatasi</em> being the most abundant. Male sand flies outnumbered females. The orientation and color of sticky traps significantly influenced capture rates, with vertical traps attracting more sand flies than horizontal traps. Orange, blue, and white traps were the most effective, while black traps were the least successful. Orange traps performed best under artificial light, while blue, orange, and white traps were most effective in dark night conditions. Vertical traps generally captured more males, while horizontal traps captured more females, particularly with specific colors.</div></div><div><h3>Conclusions</h3><div>The study highlights the importance of trap color and orientation in attracting sand flies. Understanding sand fly visual ecology and color preferences can improve trapping techniques, emphasizing the importance of careful trap design and color selection to enhance vector surveillance.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"268 ","pages":"Article 107727"},"PeriodicalIF":2.1,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144564242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular detection of bacterial and helminth pathogens in flea (Insecta: Siphonaptera) vectors: First report of D. caninum and C. burnetii in fleas from Türkiye","authors":"İlker Yasin Özdemir,&nbsp;Batuhan Aşkım Arslanhan,&nbsp;Zuhal Önder","doi":"10.1016/j.actatropica.2025.107729","DOIUrl":"10.1016/j.actatropica.2025.107729","url":null,"abstract":"<div><div>Fleas are vectors of various pathogens affecting humans and animals. This study aimed to determine the presence and genetic diversity of <em>Bartonella</em> spp<em>., Rickettsia</em> spp., <em>Coxiella burnetii</em>, and <em>Dipylidium caninum</em> in fleas. Fleas were collected from domestic animals (sheep, goat, dog, and cat) in four districts (Artova, Sulusaray, Yesilyurt, and Central) of Tokat province. The flea species were identified morphologically and then separated according to their species; pools of one to five specimens were prepared for each species. Genomic DNA from the pooled samples was extracted and screened by PCRs for bacterial species, including <em>C. burnetii, Bartonella</em> spp., <em>Rickettsia</em> spp., and also helminths such as <em>D. caninum</em>. Positive samples were sequenced for pathogen characterization, and bioinformatics analysis was performed. Of the 345 fleas identified, 99 were <em>Pulex irritans,</em> 48 were <em>Ctenocephalides canis,</em> and 198 were <em>Ctenocephalides felis.</em> PCR results revealed that <em>C. burneti</em> in 12 pools (11 pools from <em>P. irritans</em> and one pool from <em>C. felis</em>) and <em>D. caninum</em> in three pools (one pool from <em>C. felis, C. canis,</em> and <em>P. irritans</em>) from 70 flea pools were detected. Additionally, none of the flea pools were positive for <em>Rickettsia</em> spp. and <em>Bartonella</em> spp. The sequencing results confirmed the presence of <em>C. burnetii</em> and <em>D. caninum</em>. The phylogenetic analyses revealed that our <em>D. caninum</em> isolates belonged to the “<em>D. caninum</em> canine genotype” group. Our <em>C. burnetii</em> isolates obtained from <em>P. irritans</em> and <em>C. felis</em> pools showed the highest identity (99.63 % and 99.81 %, respectively) with the isolate detected in a human blood sample from Brazil (JF970260). Medically and veterinary important fleas can carry multiple pathogens, and future research on flea-borne pathogens is vital for public health in the “One Health” concept.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"268 ","pages":"Article 107729"},"PeriodicalIF":2.1,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144557224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metabolic disruptions in P. vivax malaria: Insights from four antimalarial treatment regimens","authors":"Michael N. Yakubu ,&nbsp;Victor I. Mwangi ,&nbsp;Anne C.G. Almeida ,&nbsp;Emanuelle Lira ,&nbsp;Asenate A.X. Adrião ,&nbsp;Gabriel F. dos Santos ,&nbsp;Gesiane S. Lima ,&nbsp;Lucas S. Machado ,&nbsp;Hector H.F. Koolen ,&nbsp;Tiago P. Guimarães ,&nbsp;Jessica R.S. Alves ,&nbsp;Andrea R. Chaves ,&nbsp;Boniek G. Vaz ,&nbsp;Wuelton M. Monteiro ,&nbsp;Fabio T.M. Costa ,&nbsp;Marcus V.G. Lacerda ,&nbsp;Luiz G. Gardinassi ,&nbsp;Gisely C. Melo","doi":"10.1016/j.actatropica.2025.107722","DOIUrl":"10.1016/j.actatropica.2025.107722","url":null,"abstract":"<div><div>Understanding how antimalarial regimens affect host metabolism could inform more effective <em>Plasmodium vivax</em> control strategies. This study investigated plasma metabolic alterations in <em>P. vivax</em>-infected patients treated with four antimalarial regimens using ultra-high-performance liquid chromatography-mass spectrometry. Patients received: (T1) chloroquine (CQ) for 3 days + primaquine (PQ) for 14 days; (T2) dihydroartemisinin-piperaquine (DHA-PPQ) for 3 days + PQ for 14 days; (T3) CQ + PQ42 (from day 42); or (T4) DHA-PPQ + PQ42 (from day 42). CQ-based regimens (T1, T3) caused broad metabolic perturbations involving arginine/proline, aspartate/asparagine, glutamate, nitrogen, pyrimidine, and vitamin B3 metabolism pathway. TI specifically affected alanine/aspartate, and methionine/cysteine metabolisms, while T3 influenced aminosugar, butanoate, glutathione metabolisms, glycine, serine, alanine, threonine metabolisms, tyrosine, and ubiquinone metabolisms. These disruptions have the potential to impair vascular function and immune responses, and affect redox balance and energy production, vital in parasite clearance and host recovery. Contrastingly, DHA-PPQ-based regimens (T2, T4) had distinct effects. T2 altered histidine metabolism, while T4 disrupted the carnitine shuttle, porphyrin metabolism, and plasma lipid levels; changes that may potentially impact energy homeostasis during infection, hemoglobin turnover and oxidative stress responses. Regimens lacking PQ (T3, T4) affected androgen/estrogen biosynthesis, implicating PQ to modulate hormone-related responses during treatment. These findings suggest antimalarial regimens exert regimen-specific metabolic effects, with CQ-based therapies broadly impacting amino acid and redox metabolism, and DHA-PPQ-based therapies affecting lipid and mitochondrial pathways. Mapping these metabolic signatures reveals the profound impact of these interventions on patients and support host-directed strategies for optimized vivax malaria management.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"268 ","pages":"Article 107722"},"PeriodicalIF":2.1,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144564243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of influential factors and risk area prediction of scrub typhus in Gannan region, China, based on ecological niche modelling and geographical detector","authors":"Fen Lin ,&nbsp;Kailun Pan ,&nbsp;Jian Li ,&nbsp;Chunying Wu ,&nbsp;Qingfeng Cai ,&nbsp;Hua Xue ,&nbsp;Mingpeng Li ,&nbsp;Renfa Huang","doi":"10.1016/j.actatropica.2025.107726","DOIUrl":"10.1016/j.actatropica.2025.107726","url":null,"abstract":"<div><div>This study sought to define the potential infection risk zone of scrub typhus in Gannan and investigate the factors that contribute to this risk zone. Based on the distribution data of scrub typhus cases and environmental factors in Gannan from 2015–2021, a maximum entropy ecological niche modelling was employed to forecast potential risk areas in the region. The influence of each environmental factor on the risk was quantified using a geographical detector. The maximum entropy model's prediction remained robust, with an average area under the curve value of 0.852. The key predictor variables for scrub typhus occurrence were identified as land cover type, population density, and slope. In Gannan, the high-risk areas for scrub typhus were predominantly located in the central and southern regions, with Longnan city having the highest percentage of high-risk area at 22.92 %, followed by Xinfeng county at 14.01 %. The results of the geographical detector indicated that the environmental factors influencing risk levels primarily consisted of min temperature of coldest month, mean annual sunshine duration, and mean annual relative humidity. All interactions measured strengths of 0.999 between wind speed and relative humidity, wind speed and sunshine duration, and sunshine duration and relative humidity. The findings of this study outline the risk factors influencing the incidence of scrub typhus and pinpoint potential risk areas for the disease. This information will serve as a foundation for Gannan's relevant authorities to devise more efficient surveillance and control measures.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"268 ","pages":"Article 107726"},"PeriodicalIF":2.1,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144548408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of sja-let-7 in egg production and reproductive development in female Schistosoma japonicum","authors":"Haoran Zhong ,&nbsp;Danlin Zhu ,&nbsp;Bowen Dong ,&nbsp;Hao Li ,&nbsp;Zhiqiang Fu ,&nbsp;Jinming Liu ,&nbsp;Guiquan Guan ,&nbsp;Yamei Jin","doi":"10.1016/j.actatropica.2025.107724","DOIUrl":"10.1016/j.actatropica.2025.107724","url":null,"abstract":"<div><div><em>Schistosoma japonicum</em>, a parasitic flatworm, exhibits the special biological phenomenon of male-female pairing, essential for the reproductive maturation and egg production of female worms. MicroRNAs (miRNAs) are known to regulate female reproductive development, yet the roles of individual miRNAs in schistosome reproduction remain poorly defined. Among them, the conserved let-7 family, identified in <em>S. japonicum</em> as early as 2008, has not been explored for its specific biological functions. Expression profiling of sja-let-7 was first conducted across multiple datasets and validated through qPCR. Bioinformatic tools were used to predict sja-let-7 target genes, and fluorescence <em>in situ</em> hybridization (FISH) was employed to determine sja-let-7 localization in reproductive organs. Functional studies involving sja-let-7 modulation through mimics and inhibitors <em>in vitro</em>, and agomir and antagomir treatments <em>in vivo</em>, were conducted to evaluate its impact on female reproductive development, target gene regulation, and egg production. Results showed that sja-let-7 demonstrated prominent localization in the Mehlis’ gland, ovaries, and vitellaria of female. Sjcdc23, a potential target gene of sja-let-7, was implicated to play a potential role in reproductive processes of schistosomes. Overexpression or inhibition of sja-let-7 significantly impaired egg production and quality <em>in vitro. In vivo</em> experiments demonstrated disrupted vitellaria development and reduced egg production in agomir-treated worms, while antagomir treatment also decreased egg production, suggesting that sja-let-7 is crucial for female reproductive development and egg-laying capacity, providing novel insights into miRNA-mediated regulatory mechanisms in parasitic helminths.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"268 ","pages":"Article 107724"},"PeriodicalIF":2.1,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144558784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}