Pub Date : 2025-11-07DOI: 10.1016/j.actatropica.2025.107901
Gladys Namacha , Peter Makaula , Donales R. Kapira , David Lally , Priscilla Chammudzi , Bessie P. Ntaba , Bright Mainga , Angus M. O’Ferrall , Sam Jones , John Archer , Alexandra Juhász , Lucas Cunningham , Mwai Chipeta , Arafat Falijalla , Stanley Chilumbu , Fred Minyaliwa , Michael Luhanga , Sekeleghe A. Kayuni , J. Russell Stothard , Janelisa Musaya
Conducting health research in rural settings of sub-Saharan Africa presents unique challenges and we present our experiences and lessons learned from stakeholder dialogue, community engagement and household mapping strategies for precision mapping of hybrid schistosomes in two study communities of southern Malawi. Targeting to recruit a total sample size of 2400 individuals aged 2 to 45 years, in 2022 we carried out stakeholders’ engagement at district, area and village levels through meetings with representatives from governmental and non-governmental organizations and communities. Community sensitization was achieved through village meetings and public address systems, facilitating local buy-in for a successful Global Positioning System mapping of 1214 households leading to recruitment of a total of 2319 (96.6 %) participants of the 2400 target within a 20-days period. Follow-up surveys in 2023 and 2024 retained 2006 (86.5 %) and 2014 (86.8 %) participants, respectively. Stakeholders and communities were supportive of the study activities and assisted with in kind support. Main challenges in cohort retention were recalcitrant beliefs about disease aetiologies and community displacement following cyclonic flooding. The unfamiliar concept of parasite hybridization and zoonosis in urogenital schistosomiasis required repeated, carefully tailored messaging to build understanding and trust. Our study’s experience demonstrates that engaging key stakeholders and community members builds trust, promotes acceptability and ownership, and increases the likelihood of successful implementation of health research activities.
{"title":"Precision mapping of hybrid schistosomes in urogenital schistosomiasis: Research lessons learned from stakeholder dialogue, community engagement and household access in two study communities in southern Malawi","authors":"Gladys Namacha , Peter Makaula , Donales R. Kapira , David Lally , Priscilla Chammudzi , Bessie P. Ntaba , Bright Mainga , Angus M. O’Ferrall , Sam Jones , John Archer , Alexandra Juhász , Lucas Cunningham , Mwai Chipeta , Arafat Falijalla , Stanley Chilumbu , Fred Minyaliwa , Michael Luhanga , Sekeleghe A. Kayuni , J. Russell Stothard , Janelisa Musaya","doi":"10.1016/j.actatropica.2025.107901","DOIUrl":"10.1016/j.actatropica.2025.107901","url":null,"abstract":"<div><div>Conducting health research in rural settings of sub-Saharan Africa presents unique challenges and we present our experiences and lessons learned from stakeholder dialogue, community engagement and household mapping strategies for precision mapping of hybrid schistosomes in two study communities of southern Malawi. Targeting to recruit a total sample size of 2400 individuals aged 2 to 45 years, in 2022 we carried out stakeholders’ engagement at district, area and village levels through meetings with representatives from governmental and non-governmental organizations and communities. Community sensitization was achieved through village meetings and public address systems, facilitating local buy-in for a successful Global Positioning System mapping of 1214 households leading to recruitment of a total of 2319 (96.6 %) participants of the 2400 target within a 20-days period. Follow-up surveys in 2023 and 2024 retained 2006 (86.5 %) and 2014 (86.8 %) participants, respectively. Stakeholders and communities were supportive of the study activities and assisted with in kind support. Main challenges in cohort retention were recalcitrant beliefs about disease aetiologies and community displacement following cyclonic flooding. The unfamiliar concept of parasite hybridization and zoonosis in urogenital schistosomiasis required repeated, carefully tailored messaging to build understanding and trust. Our study’s experience demonstrates that engaging key stakeholders and community members builds trust, promotes acceptability and ownership, and increases the likelihood of successful implementation of health research activities.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"272 ","pages":"Article 107901"},"PeriodicalIF":2.5,"publicationDate":"2025-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145480464","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}
Pub Date : 2025-11-07DOI: 10.1016/j.actatropica.2025.107903
José Cebrián-Carmona , Gabriela Arévalo-Pinzón , Adriana Barreto-Santamaria , Daniel E Gutiérrez-Ortegón , Marcela Gómez , Asterio Sánchez-Mirón , Concepción Mª Mesa-Valle , Alejandro Molina-Miras , José Antonio Garrido-Cárdenas , Manuel Alfonso Patarroyo
Plasmodium vivax is one of the six species of the Plasmodium genus causing malaria in humans; furthermore, it is the species having the widest worldwide distribution. Despite causing a substantial health burden, progress in developing targeted interventions against P. vivax has been hampered by limited knowledge regarding its biology and antigen repertoire. The cysteine-rich protective antigen (CyRPA) has been identified as a key antigen concerning Plasmodium parasites. CyRPA is a highly conserved Plasmodium spp. protein which is essential for P. falciparum erythrocyte invasion via its role in a multiprotein complex; however, its function in P. vivax remains poorly understood. This study has investigated PvCyRPA expression, localisation, and functional role. It demonstrates that the pvcyrpa gene is transcribed and translated into late P. vivax VCG-1 strain schizonts, its subcellular location suggests membrane association. Recombinant PvCyRPA produced in baculovirus and COS-7 systems binds to both CD71+ reticulocytes and normocytes, highlighting its role in erythrocyte interaction; >90 % of tested sera from malaria-exposed individuals recognised this protein, thus confirming its strong antigenicity. Such findings have provided the first evidence of PvCyRPA’s functional relevance regarding P. vivax and support its potential as a vaccine candidate. Future studies should be focused on identifying its receptor(s) and minimal interaction regions critical for host-parasite binding, thereby paving the way for multi-antigen, anti-P. vivax vaccine strategies.
{"title":"Plasmodium vivax cysteine-rich protective antigen (PvCyRPA), an important element for vaccine strategies targeting P. vivax, interacts with human erythrocyte surface","authors":"José Cebrián-Carmona , Gabriela Arévalo-Pinzón , Adriana Barreto-Santamaria , Daniel E Gutiérrez-Ortegón , Marcela Gómez , Asterio Sánchez-Mirón , Concepción Mª Mesa-Valle , Alejandro Molina-Miras , José Antonio Garrido-Cárdenas , Manuel Alfonso Patarroyo","doi":"10.1016/j.actatropica.2025.107903","DOIUrl":"10.1016/j.actatropica.2025.107903","url":null,"abstract":"<div><div><em>Plasmodium vivax</em> is one of the six species of the <em>Plasmodium</em> genus causing malaria in humans; furthermore, it is the species having the widest worldwide distribution. Despite causing a substantial health burden, progress in developing targeted interventions against <em>P. vivax</em> has been hampered by limited knowledge regarding its biology and antigen repertoire. The cysteine-rich protective antigen (CyRPA) has been identified as a key antigen concerning <em>Plasmodium</em> parasites. CyRPA is a highly conserved <em>Plasmodium</em> spp. protein which is essential for <em>P. falciparum</em> erythrocyte invasion via its role in a multiprotein complex; however, its function in <em>P. vivax</em> remains poorly understood. This study has investigated <em>Pv</em>CyRPA expression, localisation, and functional role. It demonstrates that the <em>pvcyrpa</em> gene is transcribed and translated into late <em>P. vivax</em> VCG-1 strain schizonts, its subcellular location suggests membrane association. Recombinant <em>Pv</em>CyRPA produced in baculovirus and COS-7 systems binds to both CD71<sup>+</sup> reticulocytes and normocytes, highlighting its role in erythrocyte interaction; >90 % of tested sera from malaria-exposed individuals recognised this protein, thus confirming its strong antigenicity. Such findings have provided the first evidence of <em>Pv</em>CyRPA’s functional relevance regarding <em>P. vivax</em> and support its potential as a vaccine candidate. Future studies should be focused on identifying its receptor(s) and minimal interaction regions critical for host-parasite binding, thereby paving the way for multi-antigen, anti-<em>P. vivax</em> vaccine strategies.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"272 ","pages":"Article 107903"},"PeriodicalIF":2.5,"publicationDate":"2025-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145476503","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}
Pub Date : 2025-11-04DOI: 10.1016/j.actatropica.2025.107898
Cintia E. Toledo-Gómez , Nalleli Loría-Cervera , Carlos N. Ibarra-Cerdeña , Ana C. Montes de Oca-Aguilar
Human activities have significantly altered tropical forest landscapes, leading to a concerning trend of biodiversity loss. In the face of such disturbance scenarios, the role of functional traits becomes crucial for species success in these transformed environments. Wing morphology, a key determinant of flight performance, may incur dispersal costs due to land use change, potentially giving rise to resilient and efficient phenotypic patterns in dispersal flight, particularly in insect vectors like Phlebotomine sand flies. Despite ample evidence demonstrating the impact of disturbance on vector occurrence, the specific response of wing morphology to these disturbance processes remains unknown. Here, we examined two opportunistic Phlebotomine sand fly species with contrasting ecological profiles. Our results show that land use change influences wing morphology, but the response is species-specific. The zoophilic Dampfomyia deleoni shifted from narrow wings in conserved forests to broader wings in disturbed habitats, a change that may reduce aerodynamic efficiency but improve dispersal capacity, likely facilitating access to scarcer and spatially segregated blood hosts. In contrast, the Leishmania vector Lutzomyia cruciata maintained stable wing morphology across landscapes. Such stability may reflect not only evolutionary canalization but also life-history trade-offs, where generalists preserve robust morphological traits that ensure success across heterogeneous environments, whereas specialists exhibit greater morphological sensitivity to habitat modification. These contrasting strategies highlight how disturbance-driven morphological responses can shape dispersal dynamics, potentially associated with host-seeking behavior and, ultimately, could modulate the epidemiology of leishmaniasis in modified tropical environments.
{"title":"Wing morphology responses to land use change: unveiling variations among opportunistic Phlebotomine sand fly species","authors":"Cintia E. Toledo-Gómez , Nalleli Loría-Cervera , Carlos N. Ibarra-Cerdeña , Ana C. Montes de Oca-Aguilar","doi":"10.1016/j.actatropica.2025.107898","DOIUrl":"10.1016/j.actatropica.2025.107898","url":null,"abstract":"<div><div>Human activities have significantly altered tropical forest landscapes, leading to a concerning trend of biodiversity loss. In the face of such disturbance scenarios, the role of functional traits becomes crucial for species success in these transformed environments. Wing morphology, a key determinant of flight performance, may incur dispersal costs due to land use change, potentially giving rise to resilient and efficient phenotypic patterns in dispersal flight, particularly in insect vectors like Phlebotomine sand flies. Despite ample evidence demonstrating the impact of disturbance on vector occurrence, the specific response of wing morphology to these disturbance processes remains unknown. Here, we examined two opportunistic Phlebotomine sand fly species with contrasting ecological profiles. Our results show that land use change influences wing morphology, but the response is species-specific. The zoophilic <em>Dampfomyia deleoni</em> shifted from narrow wings in conserved forests to broader wings in disturbed habitats, a change that may reduce aerodynamic efficiency but improve dispersal capacity, likely facilitating access to scarcer and spatially segregated blood hosts. In contrast, the <em>Leishmania</em> vector <em>Lutzomyia cruciata</em> maintained stable wing morphology across landscapes. Such stability may reflect not only evolutionary canalization but also life-history trade-offs, where generalists preserve robust morphological traits that ensure success across heterogeneous environments, whereas specialists exhibit greater morphological sensitivity to habitat modification. These contrasting strategies highlight how disturbance-driven morphological responses can shape dispersal dynamics, potentially associated with host-seeking behavior and, ultimately, could modulate the epidemiology of leishmaniasis in modified tropical environments.<!--> </div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"272 ","pages":"Article 107898"},"PeriodicalIF":2.5,"publicationDate":"2025-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145457284","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}
Pub Date : 2025-11-03DOI: 10.1016/j.actatropica.2025.107897
Yumeng Jiao , Yixuan Ni , Lu Ge , Huahan Zhan , Fuchen Xie , Nixin Hao , Ling Xuan , Hui Xia , Qiang Fang , Zhiyong Tao
Malignant tumors continue to pose a significant threat to human health, highlighting the need for innovative therapeutic approaches. This study aims to investigate the effects of Plasmodium yoelii (P. yoelii) infection on the expression of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor A (VEGFA), Von Hippel-Lindau (VHL), and p53 in tumor tissues of colon cancer-bearing mice, as well as their relationship with tumor development, thereby elucidating the antitumor mechanisms associated with Plasmodium infection. To establish a subcutaneous tumor-bearing animal model of colon cancer, CT26.WT colon cancer cells were inoculated subcutaneously into BALB/c mice. The mice were divided into the tumor control group (CT26.WT) and P. yoelii-infected group (CT26.WT + P. yoelii). The experimental group CT26.WT + P. yoelii was infected with 0.2 mL (5 × 106/mL) of P. yoelii-infected red blood cells via intraperitoneal injection. Tumor tissues were collected on the 6th, 12th, and 18th days of P. yoelii infection (tumor-bearing day 12, 18, and 24). RT-qPCR and Western blot analyses were employed to assess the mRNA and protein expression levels of HIF-1α, VHL, VEGFA, and p53 in the tumor tissues. Concurrently, tumor growth was monitored in both the groups, on the 18th day post-inoculation with P. yoelii (tumor-bearing day 24), the P. yoelii-infected group exhibited significantly downregulated expression levels of HIF-1α (P < 0.01) and VEGFA (P < 0.01) in the tumor tissue compared to the tumor control group, while the expression levels of VHL (P < 0.01) and p53 (P < 0.01) were markedly upregulated. By day 21 of tumor inoculation (16th day of P. yoelii infection), tumors in the P. yoelii-infected group ceased to grow and began to shrink significantly, indicating a remarkable inhibitory effect of P. yoelii infection on tumor growth (P < 0.001). Overall, P. yoelii infection effectively inhibits tumor development in tumor-bearing mice by downregulating the expression levels of HIF-1α and VEGFA while upregulating the expression levels of VHL and p53.
{"title":"Plasmodium yoelii infection inhibits colon cancer in mice via modulation of hypoxia-inducible factor-1α expression","authors":"Yumeng Jiao , Yixuan Ni , Lu Ge , Huahan Zhan , Fuchen Xie , Nixin Hao , Ling Xuan , Hui Xia , Qiang Fang , Zhiyong Tao","doi":"10.1016/j.actatropica.2025.107897","DOIUrl":"10.1016/j.actatropica.2025.107897","url":null,"abstract":"<div><div>Malignant tumors continue to pose a significant threat to human health, highlighting the need for innovative therapeutic approaches. This study aims to investigate the effects of <em>Plasmodium yoelii</em> (<em>P. yoelii</em>) infection on the expression of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor A (VEGFA), Von Hippel-Lindau (VHL), and p53 in tumor tissues of colon cancer-bearing mice, as well as their relationship with tumor development, thereby elucidating the antitumor mechanisms associated with <em>Plasmodium</em> infection. To establish a subcutaneous tumor-bearing animal model of colon cancer, CT26.WT colon cancer cells were inoculated subcutaneously into BALB/c mice. The mice were divided into the tumor control group (CT26.WT) and <em>P. yoelii</em>-infected group (CT26.WT + <em>P. yoelii</em>). The experimental group CT26.WT + <em>P. yoelii</em> was infected with 0.2 mL (5 × 10<sup>6</sup>/mL) of <em>P. yoelii</em>-infected red blood cells via intraperitoneal injection. Tumor tissues were collected on the 6th, 12th, and 18th days of <em>P. yoelii</em> infection (tumor-bearing day 12, 18, and 24). RT-qPCR and Western blot analyses were employed to assess the mRNA and protein expression levels of HIF-1α, VHL, VEGFA, and p53 in the tumor tissues. Concurrently, tumor growth was monitored in both the groups, on the 18th day post-inoculation with <em>P. yoelii</em> (tumor-bearing day 24), the <em>P. yoelii</em>-infected group exhibited significantly downregulated expression levels of HIF-1α (<em>P <</em> 0.01) and VEGFA (<em>P <</em> 0.01) in the tumor tissue compared to the tumor control group, while the expression levels of VHL (<em>P <</em> 0.01) and p53 (<em>P <</em> 0.01) were markedly upregulated. By day 21 of tumor inoculation (16th day of <em>P. yoelii</em> infection), tumors in the <em>P. yoelii</em>-infected group ceased to grow and began to shrink significantly, indicating a remarkable inhibitory effect of <em>P. yoelii</em> infection on tumor growth (<em>P <</em> 0.001). Overall, <em>P. yoelii</em> infection effectively inhibits tumor development in tumor-bearing mice by downregulating the expression levels of HIF-1α and VEGFA while upregulating the expression levels of VHL and p53.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"272 ","pages":"Article 107897"},"PeriodicalIF":2.5,"publicationDate":"2025-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145450469","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}
Echinococcus granulosus (E. granulosus) infection can induce host immunosuppression and chronic liver injury, with current therapeutic approaches exhibiting significant limitations. EgG1Y162, a promising vaccine candidate against E. granulosus, shows considerable potential; however, its specific effects on macrophages remain unknown, necessitating further investigation. This study employed RNA-seq to analyze the functional enrichment of differentially expressed genes (DEGs) in macrophages following EgG1Y162 transfection, aiming to elucidate its regulatory impact on cytokines. Additionally, EgG1Y162 was prepared via in vitro transcription and transfected into macrophages. Gene expression changes were subsequently assessed using quantitative reverse transcription polymerase chain reaction (RT-qPCR) and RNA sequencing (RNA-seq), complemented by KEGG and GO enrichment analyses to delineate activated signaling pathways.RNA-seq revealed 1848 upregulated and 1359 downregulated genes in macrophages. DEGs were enriched in Toll-like receptor (TLR) signaling pathway and NOD-like receptor (NLR) signaling pathway (e.g., TLR2, MyD88, and NF-κB upregulation). RT-qPCR confirmed elevated IL-6/IL-9 and reduced IL-4/interferon-gamma (IFN-γ) (p < 0.01). The TLR2/NF-κB axis is central to EgG1Y162-induced immune regulation. In-depth analysis of the transcriptomic data confirmed that activation of the TLR2/NF-κB signaling axis likely constitutes the central regulatory mechanism underlying the macrophage immune response. These results provide mechanistic insights into the immunomodulatory effects of EgG1Y162 on macrophages and may offer novel strategies for the prevention and treatment of echinococcosis.
{"title":"Transcriptome profiling reveals the immunomodulatory role of Echinococcus granulosus EgG1Y162 on macrophages in vitro","authors":"Ya Song , Mayire Aizezi , Hao Ding , Xia Chen , Ayinula Tuohetali , Mutailipu Maimaiti , Guangfeng Chen , Kalibixiati Aimulajiang","doi":"10.1016/j.actatropica.2025.107875","DOIUrl":"10.1016/j.actatropica.2025.107875","url":null,"abstract":"<div><div><em>Echinococcus granulosus</em> (<em>E. granulosus</em>) infection can induce host immunosuppression and chronic liver injury, with current therapeutic approaches exhibiting significant limitations. EgG1Y162, a promising vaccine candidate against <em>E. granulosus</em>, shows considerable potential; however, its specific effects on macrophages remain unknown, necessitating further investigation. This study employed RNA-seq to analyze the functional enrichment of differentially expressed genes (DEGs) in macrophages following EgG1Y162 transfection, aiming to elucidate its regulatory impact on cytokines. Additionally, EgG1Y162 was prepared via in vitro transcription and transfected into macrophages. Gene expression changes were subsequently assessed using quantitative reverse transcription polymerase chain reaction (RT-qPCR) and RNA sequencing (RNA-seq), complemented by KEGG and GO enrichment analyses to delineate activated signaling pathways.RNA-seq revealed 1848 upregulated and 1359 downregulated genes in macrophages. DEGs were enriched in Toll-like receptor (TLR) signaling pathway and NOD-like receptor (NLR) signaling pathway (e.g., TLR2, MyD88, and NF-κB upregulation). RT-qPCR confirmed elevated IL-6/IL-9 and reduced IL-4/interferon-gamma (IFN-γ) (<em>p</em> < 0.01). The TLR2/NF-κB axis is central to EgG1Y162-induced immune regulation. In-depth analysis of the transcriptomic data confirmed that activation of the TLR2/NF-κB signaling axis likely constitutes the central regulatory mechanism underlying the macrophage immune response. These results provide mechanistic insights into the immunomodulatory effects of EgG1Y162 on macrophages and may offer novel strategies for the prevention and treatment of echinococcosis.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"271 ","pages":"Article 107875"},"PeriodicalIF":2.5,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145353282","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}
<div><div>Cutaneous leishmaniasis (CL) is one of the most widespread neglected tropical diseases, transmitted by <em>Phlebotomus</em> sandflies and caused by protozoan parasites of the genus <em>Leishmania</em>. It poses a major global public health concern, particularly in arid and semi-arid regions where ecological and socio-environmental factors favor vector proliferation. In Algeria, CL is endemic across several regions, yet few studies have explored its long-term epidemiological dynamics in the Sahara Desert, where the disease continues to expand. This study aimed to investigate the spatio-temporal evolution and epidemiological characteristics of CL in the Sahara Desert of Algeria, specifically within the Djamaa province which represents an active and historically persistent focus of infection. Using a Bayesian analytical framework, we sought to identify demographic, temporal, and clinical determinants influencing disease occurrence and distribution, thereby providing insights for more effective control and prevention strategies. Data were obtained from the official public health records of the Djamaa province covering a 12-year period (2012–2023). Epidemiological variables included gender, age, number and anatomical site of lesions, and spatio-temporal case distribution across municipalities. Descriptive statistics and chi-square tests were applied to assess differences between groups. To account for uncertainty and the hierarchical structure of the data, a Bayesian Markov chain Monte Carlo Sampler for Multivariate Generalized Linear Mixed Model (MCMCglmm) was employed to evaluate the effects of temporal and clinical predictors on CL incidence. A total of 4436 confirmed CL cases were recorded during the study period, with a mean annual incidence of 369.7 cases. The highest peak was observed in 2012 (23.91%), followed by a gradual decline in subsequent years. Monthly distribution indicated pronounced seasonality, with maximum case occurrence in November (22.9%) and January (13.8%), reflecting the transmission dynamics of <em>Phlebotomus</em> vectors. CL affected both sexes and all age groups, but males (65.2%) and teenagers aged 10–20 years (33.7%) were the most affected, likely due to greater outdoor exposure. Lesions were mainly located on the lower extremities (64.9%), and multiple lesions were observed in 54% of patients. The Bayesian MCMCglmm analysis identified significant temporal effects (annual and monthly) and clinical variables (number and site of lesions) as major determinants shaping CL occurrence, confirming the strong seasonal and ecological dependence of the disease. The findings confirm that CL remains a major endemic health issue in the Sahara Desert of Algeria, particularly in Djamaa province. The disease exhibited clear temporal and demographic patterns linked to vector ecology and host exposure. To our knowledge, this is the first application of a Bayesian spatial model to characterize CL risk in the Northern Sahara of A
{"title":"A Bayesian modeling and retrospective analysis of cutaneous leishmaniasis in the Sahara Desert","authors":"Boutheyna Boulal , Djamel Bendjoudi , Hamza Leulmi , Haroun Chenchouni","doi":"10.1016/j.actatropica.2025.107893","DOIUrl":"10.1016/j.actatropica.2025.107893","url":null,"abstract":"<div><div>Cutaneous leishmaniasis (CL) is one of the most widespread neglected tropical diseases, transmitted by <em>Phlebotomus</em> sandflies and caused by protozoan parasites of the genus <em>Leishmania</em>. It poses a major global public health concern, particularly in arid and semi-arid regions where ecological and socio-environmental factors favor vector proliferation. In Algeria, CL is endemic across several regions, yet few studies have explored its long-term epidemiological dynamics in the Sahara Desert, where the disease continues to expand. This study aimed to investigate the spatio-temporal evolution and epidemiological characteristics of CL in the Sahara Desert of Algeria, specifically within the Djamaa province which represents an active and historically persistent focus of infection. Using a Bayesian analytical framework, we sought to identify demographic, temporal, and clinical determinants influencing disease occurrence and distribution, thereby providing insights for more effective control and prevention strategies. Data were obtained from the official public health records of the Djamaa province covering a 12-year period (2012–2023). Epidemiological variables included gender, age, number and anatomical site of lesions, and spatio-temporal case distribution across municipalities. Descriptive statistics and chi-square tests were applied to assess differences between groups. To account for uncertainty and the hierarchical structure of the data, a Bayesian Markov chain Monte Carlo Sampler for Multivariate Generalized Linear Mixed Model (MCMCglmm) was employed to evaluate the effects of temporal and clinical predictors on CL incidence. A total of 4436 confirmed CL cases were recorded during the study period, with a mean annual incidence of 369.7 cases. The highest peak was observed in 2012 (23.91%), followed by a gradual decline in subsequent years. Monthly distribution indicated pronounced seasonality, with maximum case occurrence in November (22.9%) and January (13.8%), reflecting the transmission dynamics of <em>Phlebotomus</em> vectors. CL affected both sexes and all age groups, but males (65.2%) and teenagers aged 10–20 years (33.7%) were the most affected, likely due to greater outdoor exposure. Lesions were mainly located on the lower extremities (64.9%), and multiple lesions were observed in 54% of patients. The Bayesian MCMCglmm analysis identified significant temporal effects (annual and monthly) and clinical variables (number and site of lesions) as major determinants shaping CL occurrence, confirming the strong seasonal and ecological dependence of the disease. The findings confirm that CL remains a major endemic health issue in the Sahara Desert of Algeria, particularly in Djamaa province. The disease exhibited clear temporal and demographic patterns linked to vector ecology and host exposure. To our knowledge, this is the first application of a Bayesian spatial model to characterize CL risk in the Northern Sahara of A","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"271 ","pages":"Article 107893"},"PeriodicalIF":2.5,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145421011","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}
Pub Date : 2025-11-01DOI: 10.1016/j.actatropica.2025.107891
Micaela de Melo Cordeiro Eulálio , Cindy de Oliveira Bariani , Alex Augusto Ferreira e Ferreira , Andréia Nalva Bernardi de Lima , Hallison Mota Santana , Mauro Valentino Paloschi , Sulamita da Silva Setúbal , Larissa Faustina Cruz , Ketlei Monteiro Tavares , Carolina Pereira da Silva , Milena Daniela Souza Silva , Charles Nunes Boeno , Paula Helena Santa Rita , Andreimar Martins Soares , Daniela Priscila Marchi Salvador , Juliana Pavan Zuliani
Snakebite envenomation is a neglected tropical disease with major health impacts in Latin America, where Bothrops species are responsible for vast majority of accidents. Among them, Bothrops mattogrossensis is epidemiologically relevant due to its wide distribution and clinical involvement in envenomation. This study aimed to characterize the histopathological and biochemical effects of B. mattogrossensis venom (BmV) and its isolated acidic phospholipase A₂ (BmPLA₂-A) in mice. Skeletal muscle, heart, lung, liver, kidney, and spleen were analyzed histologically, while local toxic effects were assessed through hemorrhagic activity and creatine kinase (CK) release. BmPLA₂-A induced discrete and non-significant vascular injury, inflammation, and fibrosis in skeletal muscle, along with vascular congestion and hemorrhagic foci in the heart, lungs, and kidneys. However, it did not produce measurable hemorrhagic halos or significant CK elevation, indicating limited hemorrhagic and myotoxic potential. In contrast, crude venom caused more intense and heterogeneous alterations, including extensive vascular ectasia, hemorrhage, pulmonary fibrosis, and pronounced CK elevation, demonstrating strong myotoxic and hemorrhagic activity. BmPLA₂-A and BmV induced significant hepatic vascular congestion and increased Kupffer-cell activity, with preserved hepatocyte morphology and discrete sinusoidal disorganization. Splenic tissue remained preserved, showing significant vascular congestion only in the venom-treated group. These findings demonstrate that BmPLA₂-A contributes to local inflammation and vascular damage but is not the main determinant of systemic hemorrhage or muscle necrosis, which are primarily mediated by other venom components. From a translational perspective, the identification of catalytically active yet non-myotoxic PLA₂s such as BmPLA₂-A opens avenues for pharmacological exploration, providing potential molecular tools for probing lipid signaling and therapeutic innovation.
{"title":"Histopathological alterations, local hemorrhage and myotoxic effects induced by Bothrops mattogrossensis venom and an acidic isolated phospholipase A₂","authors":"Micaela de Melo Cordeiro Eulálio , Cindy de Oliveira Bariani , Alex Augusto Ferreira e Ferreira , Andréia Nalva Bernardi de Lima , Hallison Mota Santana , Mauro Valentino Paloschi , Sulamita da Silva Setúbal , Larissa Faustina Cruz , Ketlei Monteiro Tavares , Carolina Pereira da Silva , Milena Daniela Souza Silva , Charles Nunes Boeno , Paula Helena Santa Rita , Andreimar Martins Soares , Daniela Priscila Marchi Salvador , Juliana Pavan Zuliani","doi":"10.1016/j.actatropica.2025.107891","DOIUrl":"10.1016/j.actatropica.2025.107891","url":null,"abstract":"<div><div>Snakebite envenomation is a neglected tropical disease with major health impacts in Latin America, where <em>Bothrops</em> species are responsible for vast majority of accidents. Among them, <em>Bothrops mattogrossensis</em> is epidemiologically relevant due to its wide distribution and clinical involvement in envenomation. This study aimed to characterize the histopathological and biochemical effects of <em>B. mattogrossensis</em> venom (<em>BmV</em>) and its isolated acidic phospholipase A₂ (BmPLA₂-A) in mice. Skeletal muscle, heart, lung, liver, kidney, and spleen were analyzed histologically, while local toxic effects were assessed through hemorrhagic activity and creatine kinase (CK) release. BmPLA₂-A induced discrete and non-significant vascular injury, inflammation, and fibrosis in skeletal muscle, along with vascular congestion and hemorrhagic foci in the heart, lungs, and kidneys. However, it did not produce measurable hemorrhagic halos or significant CK elevation, indicating limited hemorrhagic and myotoxic potential. In contrast, crude venom caused more intense and heterogeneous alterations, including extensive vascular ectasia, hemorrhage, pulmonary fibrosis, and pronounced CK elevation, demonstrating strong myotoxic and hemorrhagic activity. BmPLA₂-A and <em>BmV</em> induced significant hepatic vascular congestion and increased Kupffer-cell activity, with preserved hepatocyte morphology and discrete sinusoidal disorganization. Splenic tissue remained preserved, showing significant vascular congestion only in the venom-treated group. These findings demonstrate that BmPLA₂-A contributes to local inflammation and vascular damage but is not the main determinant of systemic hemorrhage or muscle necrosis, which are primarily mediated by other venom components. From a translational perspective, the identification of catalytically active yet non-myotoxic PLA₂s such as BmPLA₂-A opens avenues for pharmacological exploration, providing potential molecular tools for probing lipid signaling and therapeutic innovation.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"271 ","pages":"Article 107891"},"PeriodicalIF":2.5,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145426342","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}
Pub Date : 2025-11-01DOI: 10.1016/j.actatropica.2025.107896
Han-Dong Zhao , Hong-Bo Qian , Yan-Ping Li , Pei-Long Wang , Hong-Li Liu
Introduction
The goal of our study was to determine the plasma levels of B-type Natriuretic Peptide (BNP) in patients with hemorrhagic fever with renal syndrome (HFRS) of varying severities, and assess the predictive value of BNP for the severity of HFRS.
Material and methods
Chemiluminescence was used to measure the BNP levels in 176 patients and 41 healthy donors, and flow cytometry was conducted to test the levels of CD4+ T, CD8+ T lymphocytes, B lymphocytes, and natural killer (NK) cells. Standard laboratory methods were used to measure leukocyte and platelet counts, as well as levels of creatinine (Cr), uric acid (UA), urea, activated partial thromboplastin time (APTT), prothrombin time (PT), and fibrinogen (Fib). The colloidal gold method was employed to detect HFRS antibody levels in the patients.
Results
The findings showed that elevated plasma BNP levels were in line with HFRS severity. A positive correlation existed between the levels of BNP and those of Cr (P < 0.001, r = 0.5076), urea (P < 0.001, r = 0.5555), UA (P < 0.001, r = 0.3001), and APTT (P < 0.001, r = 0.4674). In contrast, BNP levels showed an inverse correlation with platelets and fibrinogen (P < 0.001, r =-0.5816; P < 0.001, r =-0.3905). Meanwhile, ROC demonstrated a significant predictive value of BNP for the severity of HFRS with an AUC of 0.853 (95%; CI: 0.793–0.913, P < 0.001).
Conclusions
The fluctuation of plasma BNP levels is closely linked to the severity of HFRS, indicating that it could be a useful marker for the severity monitoring of HFRS.
前言：本研究旨在测定不同严重程度肾综合征出血热（HFRS）患者血浆b型利钠肽（BNP）水平，并评估BNP对HFRS严重程度的预测价值。材料与方法：采用化学发光法检测176例患者和41例健康供者血清BNP水平，流式细胞术检测CD4+ T、CD8+ T淋巴细胞、B淋巴细胞和NK细胞水平。使用标准实验室方法测量白细胞和血小板计数，以及肌酐（Cr）、尿酸（UA）、尿素、活化部分凝血活酶时间（APTT）、凝血酶原时间（PT）和纤维蛋白原（Fib）水平。采用胶体金法检测患者HFRS抗体水平。结果：血浆BNP水平升高与HFRS严重程度一致。BNP水平与Cr （P < 0.001, r = 0.5076）、尿素（P < 0.001, r = 0.5555）、UA （P < 0.001, r = 0.3001）、APTT （P < 0.001, r = 0.4674）呈正相关。相反，BNP水平与血小板和纤维蛋白原呈负相关（P < 0.001, r =-0.5816; P < 0.001, r =-0.3905）。同时，ROC显示BNP对HFRS严重程度有显著的预测价值，AUC为0.853 （95%;CI: 0.793-0.913， P< 0.001）。结论：血浆BNP水平波动与HFRS严重程度密切相关，可作为监测HFRS严重程度的有效指标。
{"title":"B-type natriuretic peptide as a potential plasma biomarker for the severity of hemorrhagic fever with renal syndrome caused by the Hantaan virus","authors":"Han-Dong Zhao , Hong-Bo Qian , Yan-Ping Li , Pei-Long Wang , Hong-Li Liu","doi":"10.1016/j.actatropica.2025.107896","DOIUrl":"10.1016/j.actatropica.2025.107896","url":null,"abstract":"<div><h3>Introduction</h3><div>The goal of our study was to determine the plasma levels of B-type Natriuretic Peptide (BNP) in patients with hemorrhagic fever with renal syndrome (HFRS) of varying severities, and assess the predictive value of BNP for the severity of HFRS.</div></div><div><h3>Material and methods</h3><div>Chemiluminescence was used to measure the BNP levels in 176 patients and 41 healthy donors, and flow cytometry was conducted to test the levels of CD4<sup>+</sup> T, CD8<sup>+</sup> T lymphocytes, B lymphocytes, and natural killer (NK) cells. Standard laboratory methods were used to measure leukocyte and platelet counts, as well as levels of creatinine (Cr), uric acid (UA), urea, activated partial thromboplastin time (APTT), prothrombin time (PT), and fibrinogen (Fib). The colloidal gold method was employed to detect HFRS antibody levels in the patients.</div></div><div><h3>Results</h3><div>The findings showed that elevated plasma BNP levels were in line with HFRS severity. A positive correlation existed between the levels of BNP and those of Cr (P < 0.001, r = 0.5076), urea (P < 0.001, r = 0.5555), UA (P < 0.001, r = 0.3001), and APTT (P < 0.001, r = 0.4674). In contrast, BNP levels showed an inverse correlation with platelets and fibrinogen (P < 0.001, r =-0.5816; P < 0.001, r =-0.3905). Meanwhile, ROC demonstrated a significant predictive value of BNP for the severity of HFRS with an AUC of 0.853 (95%; CI: 0.793–0.913, P < 0.001).</div></div><div><h3>Conclusions</h3><div>The fluctuation of plasma BNP levels is closely linked to the severity of HFRS, indicating that it could be a useful marker for the severity monitoring of HFRS.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"271 ","pages":"Article 107896"},"PeriodicalIF":2.5,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145436571","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}
Cathepsin L1H has been identified as a potential vaccine candidate against fasciolosis. The present study was conducted to evaluate the immunoprophylactic efficacy of recombinant proFgCatL1H (rproFgCatL1H) antigen in goats subsequently challenged with the parasite. Immunization of goats with 200 µg of rproFgCatL1H formulated in Montanide™ ISA 61 VG conferred statistically significant reduction in worm recovery compared with both the infected control and adjuvant control groups, corresponding to reductions of 37.55 % and 34.07 %, respectively (p < 0.05). A negative correlation was observed between worm burden reduction and serum IgG levels (OD₄₅₀), measured both at the time of infection and at the study endpoint, although the association was not statistically significant. Scanning Electron Microscopy (SEM) analysis of adult F. gigantica recovered from vaccinated goats demonstrated pronounced tegumental damage, characterized by extensive swelling, surface erosion, and the presence of cell-like structures adhering to the tegumental surface. These findings suggest that the recombinant protein rproFgCatL1H holds promise as a potential vaccine candidate for the control of fasciolosis in goats.
{"title":"Vaccine potential of recombinant cathepsin L1H against Fasciola gigantica infection in goat","authors":"Manaw Sangfuang , Piynoot Sungsuwan , Gornrat Khumgra , Pornanan Kueakhai , Narin Changklungmoa , Prasert Sobhon , Worawit Suphamungmee , Sitthirug Roytrakul , Mananya Preyavichyapugdee , Krai Meemon , Narin Preyavichyapugdee","doi":"10.1016/j.actatropica.2025.107900","DOIUrl":"10.1016/j.actatropica.2025.107900","url":null,"abstract":"<div><div>Cathepsin L1H has been identified as a potential vaccine candidate against fasciolosis. The present study was conducted to evaluate the immunoprophylactic efficacy of recombinant proFgCatL1H (rproFgCatL1H) antigen in goats subsequently challenged with the parasite. Immunization of goats with 200 µg of rproFgCatL1H formulated in Montanide™ ISA 61 VG conferred statistically significant reduction in worm recovery compared with both the infected control and adjuvant control groups, corresponding to reductions of 37.55 % and 34.07 %, respectively (<em>p</em> < 0.05). A negative correlation was observed between worm burden reduction and serum IgG levels (OD₄₅₀), measured both at the time of infection and at the study endpoint, although the association was not statistically significant. Scanning Electron Microscopy (SEM) analysis of adult <em>F. gigantica</em> recovered from vaccinated goats demonstrated pronounced tegumental damage, characterized by extensive swelling, surface erosion, and the presence of cell-like structures adhering to the tegumental surface. These findings suggest that the recombinant protein rproFgCatL1H holds promise as a potential vaccine candidate for the control of fasciolosis in goats.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"271 ","pages":"Article 107900"},"PeriodicalIF":2.5,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145476561","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}
Pub Date : 2025-11-01DOI: 10.1016/j.actatropica.2025.107895
Maria Isabel Nogueira Di Azevedo , Walter Lilenbaum
Pathogenic Leptospira spp. cause a globally distributed zoonosis with complex transmission cycles involving multiple hosts and environments. Brazil’s vast ecological diversity and high Leptospira spp. circulation demand integrative approaches to understand the pathogen’s genetic diversity and distribution. We compiled an extensive molecular dataset of pathogenic Leptospira spp. in Brazil, encompassing sequences (n = 825) from several genetic markers and WGS data. A molecular landscape was provided based on associated metadata, including host species, geographic origin, and source type (clinical, animal, environmental). Records spanned four Brazilian biomes, with the highest diversity and number of sequences from the Atlantic Forest (69.7 %) and Amazon (22.2 %), with emphasis on large urban centers. Leptospira interrogans predominated (74.9 %), followed by L. santarosai (9.8 %), L. borgpetersenii (7.2 %), L. kirschneri (3.9 %), and L. noguchii (3.9 %). Regarding serogroups, Icterohaemorrhagiae was the most frequent (44.9 %). Hosts encompassed 78 species from 12 orders, including domestic large land animals (36 %), wild land animals (21 %), humans (15 %), pets (13.8 %), urban rodents (7.6 %), and marine mammals (1.3 %). Importantly, sequences from environmental pathogenic leptospires were also identified (5.3 %). This integrative molecular analysis reveals the extensive diversity, ecological breadth, and complex transmission dynamics of pathogenic Leptospira in those biomes. The findings underscore the importance of a One Health perspective and provide a robust foundation for standardized molecular surveillance and targeted interventions to mitigate leptospirosis burden in tropical regions.
{"title":"Ecological range and host–biome associations of pathogenic Leptospira in Brazil: A One Health perspective from a tropical area","authors":"Maria Isabel Nogueira Di Azevedo , Walter Lilenbaum","doi":"10.1016/j.actatropica.2025.107895","DOIUrl":"10.1016/j.actatropica.2025.107895","url":null,"abstract":"<div><div>Pathogenic <em>Leptospira</em> spp. cause a globally distributed zoonosis with complex transmission cycles involving multiple hosts and environments. Brazil’s vast ecological diversity and high <em>Leptospira</em> spp. circulation demand integrative approaches to understand the pathogen’s genetic diversity and distribution. We compiled an extensive molecular dataset of pathogenic <em>Leptospira</em> spp. in Brazil, encompassing sequences (<em>n</em> = 825) from several genetic markers and WGS data. A molecular landscape was provided based on associated metadata, including host species, geographic origin, and source type (clinical, animal, environmental). Records spanned four Brazilian biomes, with the highest diversity and number of sequences from the Atlantic Forest (69.7 %) and Amazon (22.2 %), with emphasis on large urban centers. <em>Leptospira interrogans</em> predominated (74.9 %), followed by L. <em>santarosai</em> (9.8 %), L. <em>borgpetersenii</em> (7.2 %), L. <em>kirschneri</em> (3.9 %), and L. <em>noguchii</em> (3.9 %). Regarding serogroups, Icterohaemorrhagiae was the most frequent (44.9 %). Hosts encompassed 78 species from 12 orders, including domestic large land animals (36 %), wild land animals (21 %), humans (15 %), pets (13.8 %), urban rodents (7.6 %), and marine mammals (1.3 %). Importantly, sequences from environmental pathogenic leptospires were also identified (5.3 %). This integrative molecular analysis reveals the extensive diversity, ecological breadth, and complex transmission dynamics of pathogenic <em>Leptospira</em> in those biomes. The findings underscore the importance of a One Health perspective and provide a robust foundation for standardized molecular surveillance and targeted interventions to mitigate leptospirosis burden in tropical regions.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"271 ","pages":"Article 107895"},"PeriodicalIF":2.5,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145436742","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}
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