Pub Date : 2025-12-10DOI: 10.1016/j.actatropica.2025.107941
Weimar David Briñez Zabaleta , Juan David Rojas Gomez , Laura Fernanda Santofimio Villa , Natalia Barrera Angarita , Juan Fernando Alzate , Yurany Eresbey Granada Garzón , Omar Cantillo-Barraza , Omar Triana-Chavez , Paola Andrea Ortiz Vargas , Daniel Alfonso Urrea
Aedes aegypti is not only the primary vector of medically important arboviruses worldwide, but also a host of a wide range of arthropod-specific viruses (ISVs), whose genomic and biological diversity remains largely unknown across most regions of Colombia. Investigating its associated microbiota including viruses and bacteria is essential, as these interactions can influence vector competence. Metatranscriptomic analysis of this vector provides quantitative insights into the presence of such microorganisms and their potential links to blood meal sources. In this study, we analyzed 320 blood-fed female A. aegypti mosquitoes collected from urban areas of Ibagué, Colombia, using RNA-Seq to identify eukaryotic, prokaryotic, and viral sequences, with particular emphasis on insect-specific viruses (ISVs). This approach allowed us to assess the diversity and relative abundance of microorganisms across four mosquito populations, infer potential feeding sources, identify and recover complete viral genomes, and detect parasite families. Despite inherent limitations related to taxonomic classification based on databases, our findings contribute to a better understanding of the ecological and epidemiological characteristics of A. aegypti populations circulating in Ibagué, Colombia, and their vector–pathogen–host interactions.
{"title":"Metatranscriptomic insights into feeding preferences, bacterial diversity, and insect-specific viruses genomics in Aedes aegypti populations from Ibagué, Colombia","authors":"Weimar David Briñez Zabaleta , Juan David Rojas Gomez , Laura Fernanda Santofimio Villa , Natalia Barrera Angarita , Juan Fernando Alzate , Yurany Eresbey Granada Garzón , Omar Cantillo-Barraza , Omar Triana-Chavez , Paola Andrea Ortiz Vargas , Daniel Alfonso Urrea","doi":"10.1016/j.actatropica.2025.107941","DOIUrl":"10.1016/j.actatropica.2025.107941","url":null,"abstract":"<div><div><em>Aedes aegypti</em> is not only the primary vector of medically important arboviruses worldwide, but also a host of a wide range of arthropod-specific viruses (ISVs), whose genomic and biological diversity remains largely unknown across most regions of Colombia. Investigating its associated microbiota including viruses and bacteria is essential, as these interactions can influence vector competence. Metatranscriptomic analysis of this vector provides quantitative insights into the presence of such microorganisms and their potential links to blood meal sources. In this study, we analyzed 320 blood-fed female <em>A. aegypti</em> mosquitoes collected from urban areas of Ibagué, Colombia, using RNA-Seq to identify eukaryotic, prokaryotic, and viral sequences, with particular emphasis on insect-specific viruses (ISVs). This approach allowed us to assess the diversity and relative abundance of microorganisms across four mosquito populations, infer potential feeding sources, identify and recover complete viral genomes, and detect parasite families. Despite inherent limitations related to taxonomic classification based on databases, our findings contribute to a better understanding of the ecological and epidemiological characteristics of <em>A. aegypti</em> populations circulating in Ibagué, Colombia, and their vector–pathogen–host interactions.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"273 ","pages":"Article 107941"},"PeriodicalIF":2.5,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145740489","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 : 2025-12-09DOI: 10.1016/j.actatropica.2025.107942
Adolfo Borges , Leonardo De Sousa , Gulnara P Borja-Cabrera , Ariana Rivera
This study assessed scorpion envenoming risk in Ecuador at provincial and district levels between 2017 and 2021, estimated national incidence and mortality rates, and identified the likely implicated taxa. Data were obtained from the Ministry of Public Health and aggregated by province and district, with incidence and mortality rates calculated per 100,000 inhabitants using annual population estimates. District-level risk was visualized with choropleth maps, and scorpion diversity and distribution were compiled from updated national inventories. A total of 1514 scorpion stings were reported between 2017 and 2021. National incidence and mortality rates (per 100,000 inhabitants) averaged 1.75 and 0.02. Regional incidence was highest in the Amazonian region (16.81), followed by the coastal (1.39) and Andean highlands (0.66). Hyperendemic districts (≥95th percentile of risk) included Taisha and Tiwintza (Morona Santiago), Arajuno (Pastaza), Flavio Alfaro (Manabí), and La Concordia (Santo Domingo de los Tsáchilas). Mortality was highest in the Amazonian and piedmont coastal regions, with 10 deaths per region and an Amazonian rate of 0.44 per 100,000 inhabitants. These areas are inhabited by Tityus species from distinct morphological and toxinological groups, notably Tityus cf. rosenbergi in western Ecuador and Tityus cisandinus in Morona Santiago and Pastaza. Geographical variation in incidence and mortality likely reflects both the distribution of noxious taxa and population density. Despite high scorpion endemicity (79.2 %), a national lethality rate of 1.32 % that appears higher than reported in other countries where scorpionism is a public health concern, and the concentration of fatalities in children (75 % in ages 1–9), Ecuador still depends on imported scorpion antivenoms, including that prepared against Centruroides species, which show low reactivity to Tityus toxins. These findings highlight the urgent need for preclinical neutralization studies to evaluate local antivenom efficacy and to investigate regional differences in clinical outcomes, to guide future adjustments to immunotherapy based on the biogeographic distribution of medically important Tityus species.
本研究评估了2017年至2021年间厄瓜多尔省和地区蝎子的入侵风险，估计了全国发病率和死亡率，并确定了可能涉及的分类群。数据从公共卫生部获得，并按省和地区汇总，使用年度人口估计数计算每10万居民的发病率和死亡率。区级风险通过地形图可视化，蝎子的多样性和分布根据更新的国家清单汇编。2017年至2021年期间，共报告了1514起蝎子蜇伤事件。全国发病率和死亡率（每10万居民）平均为1.75和0.02。亚马逊地区发病率最高（16.81），其次是沿海地区（1.39）和安第斯高原地区（0.66）。高流行区（≥95百分位风险）包括Taisha和Tiwintza （Morona Santiago）、Arajuno （Pastaza）、Flavio Alfaro （Manabí）和La Concordia （Santo Domingo de los Tsáchilas）。亚马逊和山前沿海地区的死亡率最高，每个地区有10人死亡，亚马逊地区的死亡率为每10万居民0.44人。这些地区居住着来自不同形态和毒理学类群的Tityus物种，特别是厄瓜多尔西部的Tityus cfr . rosenbergi和Morona Santiago和Pastaza的Tityus cisandinus。发病率和死亡率的地理差异可能反映了有害分类群的分布和种群密度。尽管蝎子的流行率很高（79.2%），全国致死率为1.32%，似乎高于蝎子病已成为公共卫生问题的其他国家的报告，而且死亡主要发生在儿童中（1-9岁的儿童占75%），厄瓜多尔仍然依赖进口蝎子抗蛇毒血清，包括针对对Tityus毒素反应性较低的Centruroides物种制备的抗蛇毒血清。这些发现突出了临床前中和研究的迫切需要，以评估局部抗蛇毒血清疗效，并调查临床结果的区域差异，指导未来根据医学上重要的Tityus物种的生物地理分布调整免疫治疗。
{"title":"Scorpion envenoming in Ecuador: district-level risk, updated scorpion diversity, and challenges for treatment and public health","authors":"Adolfo Borges , Leonardo De Sousa , Gulnara P Borja-Cabrera , Ariana Rivera","doi":"10.1016/j.actatropica.2025.107942","DOIUrl":"10.1016/j.actatropica.2025.107942","url":null,"abstract":"<div><div>This study assessed scorpion envenoming risk in Ecuador at provincial and district levels between 2017 and 2021, estimated national incidence and mortality rates, and identified the likely implicated taxa. Data were obtained from the Ministry of Public Health and aggregated by province and district, with incidence and mortality rates calculated per 100,000 inhabitants using annual population estimates. District-level risk was visualized with choropleth maps, and scorpion diversity and distribution were compiled from updated national inventories. A total of 1514 scorpion stings were reported between 2017 and 2021. National incidence and mortality rates (per 100,000 inhabitants) averaged 1.75 and 0.02. Regional incidence was highest in the Amazonian region (16.81), followed by the coastal (1.39) and Andean highlands (0.66). Hyperendemic districts (≥95th percentile of risk) included Taisha and Tiwintza (Morona Santiago), Arajuno (Pastaza), Flavio Alfaro (Manabí), and La Concordia (Santo Domingo de los Tsáchilas). Mortality was highest in the Amazonian and piedmont coastal regions, with 10 deaths per region and an Amazonian rate of 0.44 per 100,000 inhabitants. These areas are inhabited by <em>Tityus</em> species from distinct morphological and toxinological groups, notably <em>Tityus</em> cf. <em>rosenbergi</em> in western Ecuador and <em>Tityus cisandinus</em> in Morona Santiago and Pastaza. Geographical variation in incidence and mortality likely reflects both the distribution of noxious taxa and population density. Despite high scorpion endemicity (79.2 %), a national lethality rate of 1.32 % that appears higher than reported in other countries where scorpionism is a public health concern, and the concentration of fatalities in children (75 % in ages 1–9), Ecuador still depends on imported scorpion antivenoms, including that prepared against <em>Centruroides</em> species, which show low reactivity to <em>Tityus</em> toxins. These findings highlight the urgent need for preclinical neutralization studies to evaluate local antivenom efficacy and to investigate regional differences in clinical outcomes, to guide future adjustments to immunotherapy based on the biogeographic distribution of medically important <em>Tityus</em> species.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"273 ","pages":"Article 107942"},"PeriodicalIF":2.5,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145740479","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}
Chagas disease, caused by the hemoflagellate protozoan Trypanosoma cruzi, is a parasitic zoonosis classified as a neglected tropical disease. With an estimated global prevalence of 6 to 7 million individuals, the disease represents a significant global public health concern due to migration patterns that have expanded its epidemiological profile beyond the endemic regions of Latin America. Traditional etiological treatment relies on the nitroderivatives benznidazole and nifurtimox. While these drugs are highly effective in the acute phase, their ability to halt or significantly limit the progression of the organic damage established in the chronic phase is limited. Furthermore, their therapeutic effectiveness is challenged by variability in parasite susceptibility and the potential for resistance to emerge, a complex and multifactorial phenomenon.
This systematic review synthesizes the molecular mechanisms of resistance and differential susceptibility in T. cruzi. The evidence highlights the involvement of several factors, including the modulation of key enzymes required for pro-drug activation, the overexpression of ABC transporters and other related transporters, and the adaptation of the antioxidant defense system. These collectively represent a multifactorial mechanism that undermines infection control. The plasticity and genetic heterogeneity of the T. cruzi Discrete Typing Units (DTUs) underpin the observed variability in this resistance response.
Therapeutic failure transforms patients into persistent reservoirs, which perpetuates the chain of parasite transmission. The concern that resistance established in laboratory models may translate into clinical settings, coupled with the resulting increase in morbidity and mortality and the socioeconomic burden, underscores the urgent need to develop new drugs designed to evade these mechanisms of reduced susceptibility.
{"title":"Mechanisms of resistance of Trypanosoma cruzi to benznidazole and nifurtimox: Molecular implications and multifaceted impact","authors":"Paulina Ochoa-Martínez , Jaime López-Domínguez , Aracely López-Monteon , Rebeca Georgina Manning-Cela , Angel Ramos-Ligonio","doi":"10.1016/j.actatropica.2025.107940","DOIUrl":"10.1016/j.actatropica.2025.107940","url":null,"abstract":"<div><div>Chagas disease, caused by the hemoflagellate protozoan Trypanosoma cruzi, is a parasitic zoonosis classified as a neglected tropical disease. With an estimated global prevalence of 6 to 7 million individuals, the disease represents a significant global public health concern due to migration patterns that have expanded its epidemiological profile beyond the endemic regions of Latin America. Traditional etiological treatment relies on the nitroderivatives benznidazole and nifurtimox. While these drugs are highly effective in the acute phase, their ability to halt or significantly limit the progression of the organic damage established in the chronic phase is limited. Furthermore, their therapeutic effectiveness is challenged by variability in parasite susceptibility and the potential for resistance to emerge, a complex and multifactorial phenomenon.</div><div>This systematic review synthesizes the molecular mechanisms of resistance and differential susceptibility in <em>T. cruzi</em>. The evidence highlights the involvement of several factors, including the modulation of key enzymes required for pro-drug activation, the overexpression of ABC transporters and other related transporters, and the adaptation of the antioxidant defense system. These collectively represent a multifactorial mechanism that undermines infection control. The plasticity and genetic heterogeneity of the <em>T. cruzi</em> Discrete Typing Units (DTUs) underpin the observed variability in this resistance response.</div><div>Therapeutic failure transforms patients into persistent reservoirs, which perpetuates the chain of parasite transmission. The concern that resistance established in laboratory models may translate into clinical settings, coupled with the resulting increase in morbidity and mortality and the socioeconomic burden, underscores the urgent need to develop new drugs designed to evade these mechanisms of reduced susceptibility.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"273 ","pages":"Article 107940"},"PeriodicalIF":2.5,"publicationDate":"2025-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145712982","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 : 2025-12-06DOI: 10.1016/j.actatropica.2025.107938
Xinyuan Wang , Zhenyu Zhong , Yunfang Shan , Qingyun Guo , Zhibin Cheng , Xinglong Song , Congshan Yang , Jiade Bai , Qingxun Zhang
Myiasis is the infestation of humans and other warm-blooded animals with dipterous larvae. In the current study, a total of 40 maggots were collected from the cutaneous lesions of the Chinese Milu (Elaphurus davidianus) in China. Based on morphological identification, the third-instar larvae were classified as Chrysomya bezziana. To accurately identify this species, genomic DNA from the larvae was analyzed using the mitochondrial cytochrome c oxidase subunit I (COI) gene. The findings indicated that the examined larvae were unequivocally consistent with the Old World screwworm fly, C. bezziana. This study firstly documented the cases of cutaneous myiasis caused by C. bezziana in Chinese Milu, and provided effective strategies for the prevention and control of myiasis.
{"title":"Old World screwworm myiasis: first report of Chrysomya bezziana in Chinese Milu (Elaphurus davidianus)","authors":"Xinyuan Wang , Zhenyu Zhong , Yunfang Shan , Qingyun Guo , Zhibin Cheng , Xinglong Song , Congshan Yang , Jiade Bai , Qingxun Zhang","doi":"10.1016/j.actatropica.2025.107938","DOIUrl":"10.1016/j.actatropica.2025.107938","url":null,"abstract":"<div><div>Myiasis is the infestation of humans and other warm-blooded animals with dipterous larvae. In the current study, a total of 40 maggots were collected from the cutaneous lesions of the Chinese Milu (<em>Elaphurus davidianus</em>) in China. Based on morphological identification, the third-instar larvae were classified as <em>Chrysomya bezziana</em>. To accurately identify this species, genomic DNA from the larvae was analyzed using the mitochondrial cytochrome c oxidase subunit I (COI) gene. The findings indicated that the examined larvae were unequivocally consistent with the Old World screwworm fly, <em>C. bezziana</em>. This study firstly documented the cases of cutaneous myiasis caused by <em>C. bezziana</em> in Chinese Milu, and provided effective strategies for the prevention and control of myiasis.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"273 ","pages":"Article 107938"},"PeriodicalIF":2.5,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145705752","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 : 2025-12-06DOI: 10.1016/j.actatropica.2025.107939
Eira Nurfarisha Mohd Latif , Aizura Syafinaz Ahmad Adlan , Yee-Ling Lau , Fei-Wen Cheong
Human infections with the zoonotic Plasmodium cynomolgi are rising across Southeast Asia. This parasite employs two Duffy binding proteins (DBPs), PcDBP1(II) and PcDBP2(II), which interact with the Duffy antigen receptor chemokine (DARC) for erythrocyte invasion. Previous studies on P. cynomolgi DBPs have reported two distinct haplotype groups (groups 1 and 2) in Peninsular Malaysia. In this study, the differential erythrocyte binding activity of PcDBP1(II) and PcDBP2(II) haplotypes was investigated. Four isolates were selected for each DBP: group 1 consisted of a recent field isolate and the old reference isolate Strain B, whereas group 2 included a recent field isolate and the old reference isolate Berok. All isolates were cloned into the pDisplay-AcGFP1 vector and transfected into COS-7 cells. The transfected cells were incubated with human erythrocytes/reticulocytes and macaque erythrocytes at 1 % haematocrit. The binding activity was assessed by counting the number of rosette formations. Result showed a significant difference (P < 0.05) in binding between group 1 isolates (recent vs old) for PcDBP1(II) with macaque erythrocytes, while no differences in binding were seen with PcDBP2(II) isolates. Notably, the recent PcDBP1(II) isolate exhibited significantly higher binding activity compared to the old isolate, indicating that the protein may have evolved over time to enhance parasite invasion into macaque erythrocytes. However, both PcDBPs showed no binding with human erythrocytes or reticulocytes. This study provides the first evidence that variations in PcDBP1(II) and PcDBP2(II) alone do not explain the observed differences in binding activity, suggesting that additional parasite–host interactions may be required for human erythrocyte or reticulocyte invasion.
东南亚人畜共患的食蟹疟原虫的人类感染正在上升。这种寄生虫使用两种Duffy结合蛋白PcDBP1（II）和PcDBP2(II)，它们与Duffy抗原受体趋化因子（DARC）相互作用以入侵红细胞。先前对cynomolgi P. dbp的研究报道了马来西亚半岛两个不同的单倍型群体（群体1和群体2）。本研究研究了PcDBP1（II）和PcDBP2（II）单倍型红细胞结合活性的差异。每个DBP选择4株分离株：第1组由一株最近的野外分离株和旧参考分离株B组成，第2组由一株最近的野外分离株和旧参考分离株Berok组成。将所有分离株克隆到pDisplay-AcGFP1载体上，转染到COS-7细胞中。转染后的细胞与人红细胞/网织红细胞和猕猴红细胞在1%的红细胞压积下孵育。结合活性是通过计算玫瑰结形成的数量来评估的。结果显示1组PcDBP1（II）与猕猴红细胞的结合有显著差异（P < 0.05），而PcDBP2（II）与猕猴红细胞的结合无显著差异。值得注意的是，与旧的分离物相比，最新的PcDBP1（II）分离物表现出明显更高的结合活性，这表明该蛋白可能随着时间的推移而进化，以增强寄生虫对猕猴红细胞的入侵。然而，两种PcDBPs均未与人红细胞或网织红细胞结合。该研究首次证明，单独的PcDBP1（II）和PcDBP2（II）的变异并不能解释观察到的结合活性差异，这表明人类红细胞或网织红细胞入侵可能需要额外的寄生虫-宿主相互作用。
{"title":"Characterisation of erythrocyte binding activity of Plasmodium cynomolgi duffy binding protein haplotypes from Macaca fascicularis in Peninsular Malaysia","authors":"Eira Nurfarisha Mohd Latif , Aizura Syafinaz Ahmad Adlan , Yee-Ling Lau , Fei-Wen Cheong","doi":"10.1016/j.actatropica.2025.107939","DOIUrl":"10.1016/j.actatropica.2025.107939","url":null,"abstract":"<div><div>Human infections with the zoonotic <em>Plasmodium cynomolgi</em> are rising across Southeast Asia. This parasite employs two Duffy binding proteins (DBPs), PcDBP1(II) and PcDBP2(II), which interact with the Duffy antigen receptor chemokine (DARC) for erythrocyte invasion. Previous studies on <em>P. cynomolgi</em> DBPs have reported two distinct haplotype groups (groups 1 and 2) in Peninsular Malaysia. In this study, the differential erythrocyte binding activity of PcDBP1(II) and PcDBP2(II) haplotypes was investigated. Four isolates were selected for each DBP: group 1 consisted of a recent field isolate and the old reference isolate Strain B, whereas group 2 included a recent field isolate and the old reference isolate Berok. All isolates were cloned into the pDisplay-AcGFP1 vector and transfected into COS-7 cells. The transfected cells were incubated with human erythrocytes/reticulocytes and macaque erythrocytes at 1 % haematocrit. The binding activity was assessed by counting the number of rosette formations. Result showed a significant difference (<em>P</em> < 0.05) in binding between group 1 isolates (recent vs old) for PcDBP1(II) with macaque erythrocytes, while no differences in binding were seen with PcDBP2(II) isolates. Notably, the recent PcDBP1(II) isolate exhibited significantly higher binding activity compared to the old isolate, indicating that the protein may have evolved over time to enhance parasite invasion into macaque erythrocytes. However, both PcDBPs showed no binding with human erythrocytes or reticulocytes. This study provides the first evidence that variations in PcDBP1(II) and PcDBP2(II) alone do not explain the observed differences in binding activity, suggesting that additional parasite–host interactions may be required for human erythrocyte or reticulocyte invasion.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"273 ","pages":"Article 107939"},"PeriodicalIF":2.5,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145706910","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 : 2025-12-05DOI: 10.1016/j.actatropica.2025.107935
Muhammad Fajri Rohkmad , Semuel Sandy , Mirna Widiyanti , Setyo Adiningsih , Agung Puja Kesuma , Yustinus Maladan , Yusnita Mirna Anggraeni , Tri Ramadhani , Mara Ipa , Muhammad Choirul Hidajat , Hanna Kawulur , Chandra Mukti Kurniawan , Adrianus Don Kopo , NLP Indi Dharmayanti , Triwibowo Ambar Garjito , Antonius Oktavian , Harimat Hendarwan
This study evaluates the performance of three diagnostic methods for malaria detection, Rapid Diagnostic Tests (RDTs), microscopy, and Polymerase Chain Reaction (PCR), in the high-transmission area of Keerom Regency, Papua Province, Indonesia. With malaria posing a significant health threat, particularly in Indonesia, accurate and timely diagnosis is crucial for effective treatment and disease management. The study involved 234 participants suspected of having uncomplicated malaria, with blood samples analyzed using all three diagnostic methods. Results indicated that PCR identified 42.3 % of malaria cases, while microscopy and RDTs detected 26.5 % and 22.6 %, respectively. Notably, PCR revealed a substantial number of cases missed by microscopy and RDTs, highlighting the limitations of these methods in low-parasitemia situations. The sensitivity and specificity of microscopy and RDTs were assessed against PCR as the reference standard, revealing significant discrepancies in diagnostic accuracy. The findings underscore the need for enhanced diagnostic strategies to improve case detection and support elimination efforts in Keerom regency, Papua, Indonesia
{"title":"Performance comparison of rapid diagnostic test, microscopy, and polymerase chain reaction for Malaria detection in high-transmission area, Keerom Regency, Papua Province, Indonesia","authors":"Muhammad Fajri Rohkmad , Semuel Sandy , Mirna Widiyanti , Setyo Adiningsih , Agung Puja Kesuma , Yustinus Maladan , Yusnita Mirna Anggraeni , Tri Ramadhani , Mara Ipa , Muhammad Choirul Hidajat , Hanna Kawulur , Chandra Mukti Kurniawan , Adrianus Don Kopo , NLP Indi Dharmayanti , Triwibowo Ambar Garjito , Antonius Oktavian , Harimat Hendarwan","doi":"10.1016/j.actatropica.2025.107935","DOIUrl":"10.1016/j.actatropica.2025.107935","url":null,"abstract":"<div><div>This study evaluates the performance of three diagnostic methods for malaria detection, Rapid Diagnostic Tests (RDTs), microscopy, and Polymerase Chain Reaction (PCR), in the high-transmission area of Keerom Regency, Papua Province, Indonesia. With malaria posing a significant health threat, particularly in Indonesia, accurate and timely diagnosis is crucial for effective treatment and disease management. The study involved 234 participants suspected of having uncomplicated malaria, with blood samples analyzed using all three diagnostic methods. Results indicated that PCR identified 42.3 % of malaria cases, while microscopy and RDTs detected 26.5 % and 22.6 %, respectively. Notably, PCR revealed a substantial number of cases missed by microscopy and RDTs, highlighting the limitations of these methods in low-parasitemia situations. The sensitivity and specificity of microscopy and RDTs were assessed against PCR as the reference standard, revealing significant discrepancies in diagnostic accuracy. The findings underscore the need for enhanced diagnostic strategies to improve case detection and support elimination efforts in Keerom regency, Papua, Indonesia</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"273 ","pages":"Article 107935"},"PeriodicalIF":2.5,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145695869","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 : 2025-12-05DOI: 10.1016/j.actatropica.2025.107937
Attila J Trájer
The invasive bridge vector mosquito Aedes albopictus has been increasingly detected across Europe, posing potential risks for arboviral disease transmission. Urban-scale assessments of its expansion remain scarce in Central Europe. The establishment and spread of Ae. albopictus in Budapest were analysed between 2018 and 2025 using spatio-temporal mapping, seasonal observations, and indicator-based ecological modelling, complemented by ensemble machine learning approaches. Occurrence patterns followed a logistic growth trajectory (R² = 0.995), with colonization rising from sparse foci in 2020 to over 85% of districts by 2025. Seasonal activity extended from late April to mid-October, peaking in early September. Ensemble machine learning models consistently achieved high predictive performance, with key predictors included urban fabric, temperature, topography, and precipitation-related indices (bio18; Köppen Aridity Index) while other factors contributed variably. Ecological associations were strongest with urbanized land cover (discontinuous and continuous urban fabric, industrial areas), specific soil types such as fluvent entisols, and humid temperate climates (Köppen Cfa). K-means clustering and decision tree analyses distinguished seven ecological clusters across Budapest, ranging from warm, densely built urban cores to cooler, shaded peri‑urban and forested zones. Conceptually linking ecological clusters to the Sustainable Development Goals highlighted spatially heterogeneous intersections with health (SDG 3), urban sustainability (SDG 11), water management (SDG 6), climate action (SDG 13), and biodiversity conservation (SDG 15). These findings provide a baseline for predicting urban vector expansion, informing early warning systems, and guiding public health interventions and vector control strategies in European metropolitan regions.
{"title":"Ecological determinants and indicator-based analysis of Aedes albopictus expansion in a Central European metropolis: implications for urban sustainability","authors":"Attila J Trájer","doi":"10.1016/j.actatropica.2025.107937","DOIUrl":"10.1016/j.actatropica.2025.107937","url":null,"abstract":"<div><div>The invasive bridge vector mosquito <em>Aedes albopictus</em> has been increasingly detected across Europe, posing potential risks for arboviral disease transmission. Urban-scale assessments of its expansion remain scarce in Central Europe. The establishment and spread of <em>Ae. albopictus</em> in Budapest were analysed between 2018 and 2025 using spatio-temporal mapping, seasonal observations, and indicator-based ecological modelling, complemented by ensemble machine learning approaches. Occurrence patterns followed a logistic growth trajectory (R² = 0.995), with colonization rising from sparse foci in 2020 to over 85% of districts by 2025. Seasonal activity extended from late April to mid-October, peaking in early September. Ensemble machine learning models consistently achieved high predictive performance, with key predictors included urban fabric, temperature, topography, and precipitation-related indices (bio18; Köppen Aridity Index) while other factors contributed variably. Ecological associations were strongest with urbanized land cover (discontinuous and continuous urban fabric, industrial areas), specific soil types such as fluvent entisols, and humid temperate climates (Köppen Cfa). K-means clustering and decision tree analyses distinguished seven ecological clusters across Budapest, ranging from warm, densely built urban cores to cooler, shaded peri‑urban and forested zones. Conceptually linking ecological clusters to the Sustainable Development Goals highlighted spatially heterogeneous intersections with health (SDG 3), urban sustainability (SDG 11), water management (SDG 6), climate action (SDG 13), and biodiversity conservation (SDG 15). These findings provide a baseline for predicting urban vector expansion, informing early warning systems, and guiding public health interventions and vector control strategies in European metropolitan regions.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"273 ","pages":"Article 107937"},"PeriodicalIF":2.5,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145699349","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 : 2025-12-04DOI: 10.1016/j.actatropica.2025.107934
Sudarson Sundarrajan , Santharam S Katta , Sridhar KN , Suraj Jagtap , Nagaraj C
Dengue is an endemic disease in over 100 countries, causing an estimated 500,000 hospitalizations each year. The global mortality rate for severe dengue infections is around 2.5 %. India is a major dengue hotspot, accounting for almost a third of all global cases. Despite this significant burden, there are limited studies on the circulating serotypes and genetic lineages of the dengue virus (DENV) within the country. This retrospective study investigates the distribution and genetic diversity of circulating dengue virus (DENV) variants based on clinical samples collected from healthcare centres between 2019 and 2024 in South India. A total of 1015 samples from dengue patients tested positive for at least one of the dengue NS1, IgM, or IgG markers. Among these, 210 NS1-positive samples underwent DENV serotyping via RT-PCR, and 84 of those were further characterized through Sanger sequencing of the C-prM gene to determine genotype and lineage associations. The analysis revealed a decline in dengue infection rates with increasing age, supported by a corresponding rise in IgG seropositivity. Notably, individuals under 20 years of age exhibited a significantly higher frequency of severe disease compared to older age groups. All four DENV serotypes, DENV-1 through DENV-4, were detected across the study period, with a shift in dominant serotype approximately every 2–3 years. DENV-2 and DENV-3 emerged as the most prevalent serotypes. Phylogenetic analysis identified the following genotype-lineage associations: DENV-1 as Genotype III (Lineage: 1III_A), DENV-2 as Genotype II (Cosmopolitan) (Lineages: 2II_A and 2II_F), DENV-3 as Genotype III (Lineage: 3III_B), and DENV-4 as Genotype I (Lineage: 4I_B). These findings underscore the dynamic nature of dengue virus transmission and genetic evolution in the region, emphasizing the importance of age-specific surveillance and targeted prevention strategies. This study contributes valuable insights into local DENV circulation patterns, which are critical for informing diagnostic, therapeutic, and vaccine development efforts.
{"title":"Temporal genomic diversity of Dengue virus in South India from 2019 to 2024","authors":"Sudarson Sundarrajan , Santharam S Katta , Sridhar KN , Suraj Jagtap , Nagaraj C","doi":"10.1016/j.actatropica.2025.107934","DOIUrl":"10.1016/j.actatropica.2025.107934","url":null,"abstract":"<div><div>Dengue is an endemic disease in over 100 countries, causing an estimated 500,000 hospitalizations each year. The global mortality rate for severe dengue infections is around 2.5 %. India is a major dengue hotspot, accounting for almost a third of all global cases. Despite this significant burden, there are limited studies on the circulating serotypes and genetic lineages of the dengue virus (DENV) within the country. This retrospective study investigates the distribution and genetic diversity of circulating dengue virus (DENV) variants based on clinical samples collected from healthcare centres between 2019 and 2024 in South India. A total of 1015 samples from dengue patients tested positive for at least one of the dengue NS1, IgM, or IgG markers. Among these, 210 NS1-positive samples underwent DENV serotyping via RT-PCR, and 84 of those were further characterized through Sanger sequencing of the C-prM gene to determine genotype and lineage associations. The analysis revealed a decline in dengue infection rates with increasing age, supported by a corresponding rise in IgG seropositivity. Notably, individuals under 20 years of age exhibited a significantly higher frequency of severe disease compared to older age groups. All four DENV serotypes, DENV-1 through DENV-4, were detected across the study period, with a shift in dominant serotype approximately every 2–3 years. DENV-2 and DENV-3 emerged as the most prevalent serotypes. Phylogenetic analysis identified the following genotype-lineage associations: DENV-1 as Genotype III (Lineage: 1III_A), DENV-2 as Genotype II (Cosmopolitan) (Lineages: 2II_A and 2II_F), DENV-3 as Genotype III (Lineage: 3III_B), and DENV-4 as Genotype I (Lineage: 4I_B). These findings underscore the dynamic nature of dengue virus transmission and genetic evolution in the region, emphasizing the importance of age-specific surveillance and targeted prevention strategies. This study contributes valuable insights into local DENV circulation patterns, which are critical for informing diagnostic, therapeutic, and vaccine development efforts.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"273 ","pages":"Article 107934"},"PeriodicalIF":2.5,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145695902","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 : 2025-12-04DOI: 10.1016/j.actatropica.2025.107933
Amirreza Meydani , Shuai Wang , Robert Bergquist , Flavio Lopes Ribeiro , Delphis F. Levia
Extreme climate variables are increasingly important for understanding the distribution of Biomphalaria snails, the intermediate hosts of Schistosoma mansoni. While many studies focus on long-term averages, our approach emphasizes the role of climatic extreme events and their seasonal timing in shaping habitat persistence. We applied spatially explicit Random Forest (RF) species distribution models with spatial cross-validation and bootstrap aggregation to produce robust and transferable predictions of snail habitat suitability, and then ranked the influence of extreme climate variables using SHapley Additive exPlanations (SHAP) values and partial dependence plots. The models performed well, with average area under curve (AUC) values of 0.75 across species and partial AUC ratios greater than one, confirming the robustness of the predictions. Precipitation seasonality, multi-month drought indices, surface absorbed solar radiation extremes, and diurnal air temperature range were the highest-ranked drivers, though their influence was not uniform across snail species. Biomphalaria glabrata was most responsive to seasonal recharge, while B. straminea showed resilience to variability and often persisted in man-made habitats. Biomphalaria tenagophila was more constrained by drought and radiation stress. Spatial comparisons between 1995 and 2020 indicated expansions and contractions in various states, with new hotspots emerging in southeastern and central Brazil, while habitat suitability declined in drought-prone regions, such as in the State of Pernambuco. These results demonstrate that climate extreme events, in addition to long-term baseline changes, drive the spatially heterogeneous redistribution of Biomphalaria habitats. Also, our findings highlight the need for species-specific monitoring, integration of water infrastructure management, and forward-looking surveillance strategies that address both climate variability and landscapes modified by humans.
{"title":"Climate extremes and the dynamic reshaping of snail habitat: implications for the spatiotemporal heterogeneity of schistosomal vulnerability in Brazil","authors":"Amirreza Meydani , Shuai Wang , Robert Bergquist , Flavio Lopes Ribeiro , Delphis F. Levia","doi":"10.1016/j.actatropica.2025.107933","DOIUrl":"10.1016/j.actatropica.2025.107933","url":null,"abstract":"<div><div>Extreme climate variables are increasingly important for understanding the distribution of <em>Biomphalaria</em> snails, the intermediate hosts of <em>Schistosoma mansoni</em>. While many studies focus on long-term averages, our approach emphasizes the role of climatic extreme events and their seasonal timing in shaping habitat persistence. We applied spatially explicit Random Forest (RF) species distribution models with spatial cross-validation and bootstrap aggregation to produce robust and transferable predictions of snail habitat suitability, and then ranked the influence of extreme climate variables using SHapley Additive exPlanations (SHAP) values and partial dependence plots. The models performed well, with average area under curve (AUC) values of 0.75 across species and partial AUC ratios greater than one, confirming the robustness of the predictions. Precipitation seasonality, multi-month drought indices, surface absorbed solar radiation extremes, and diurnal air temperature range were the highest-ranked drivers, though their influence was not uniform across snail species. <em>Biomphalaria glabrata</em> was most responsive to seasonal recharge, while <em>B. straminea</em> showed resilience to variability and often persisted in man-made habitats. <em>Biomphalaria tenagophila</em> was more constrained by drought and radiation stress. Spatial comparisons between 1995 and 2020 indicated expansions and contractions in various states, with new hotspots emerging in southeastern and central Brazil, while habitat suitability declined in drought-prone regions, such as in the State of Pernambuco. These results demonstrate that climate extreme events, in addition to long-term baseline changes, drive the spatially heterogeneous redistribution of <em>Biomphalaria</em> habitats. Also, our findings highlight the need for species-specific monitoring, integration of water infrastructure management, and forward-looking surveillance strategies that address both climate variability and landscapes modified by humans.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"273 ","pages":"Article 107933"},"PeriodicalIF":2.5,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145686802","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 : 2025-12-01DOI: 10.1016/j.actatropica.2025.107931
Caroline M. Meira , Anna V. Serafim , Edson A. Adriano , Antonio A.M. Maia
Myxozoa are a highly diverse group of cnidarian parasites, with approximately 3070 described species. This study describes a new species, Myxobolus mirandensis n. sp., based on morphological, molecular, and histopathological analyses. The parasite was found in Salminus brasiliensis (dourado), one of the largest and most economically and recreationally important freshwater fish species in South America. Specimens of S. brasiliensis were collected from the Miranda River in the Brazilian Pantanal, with a prevalence of the infection of 63.6 % (7/11). White and elongated plasmodia were observed in the gill filaments. Pear-shaped myxospores measured 10.1 ± 0.3 µm in length, 6.6 ± 0.3 µm in width, and 5.1 ± 0.1 µm in thickness. Nematocysts were elongated and occupied more than half of the spore body, measuring 4.9 ± 0.3 µm in length and 1.9 ± 0.2 µm in width. Histopathological analysis revealed plasmodia developing in the epithelial tissue at the distal ends of the gill filaments, resulting in compression of adjacent tissues and structures. A thin connective tissue capsule surrounded the plasmodia, and numerous granulocytic cells were observed in the tissue adjacent to the plasmodia. Sequencing of the small subunit ribosomal DNA (SSU rDNA) yielded a 1954 bp fragment. Phylogenetic analysis showed M. mirandensis grouping with Myxobolus oliveirai and Myxobolus filamentum, both reported in Bryconidae hosts. This represents the seventh record of a myxozoan infecting S. brasiliensis.
{"title":"Taxonomy and histopathology of Myxobolus mirandensis n. sp. parasite of the gills of Salminus brasiliensis from the Brazilian Pantanal wetland","authors":"Caroline M. Meira , Anna V. Serafim , Edson A. Adriano , Antonio A.M. Maia","doi":"10.1016/j.actatropica.2025.107931","DOIUrl":"10.1016/j.actatropica.2025.107931","url":null,"abstract":"<div><div>Myxozoa are a highly diverse group of cnidarian parasites, with approximately 3070 described species. This study describes a new species, <em>Myxobolus mirandensis</em> n. sp., based on morphological, molecular, and histopathological analyses. The parasite was found in <em>Salminus brasiliensis</em> (dourado), one of the largest and most economically and recreationally important freshwater fish species in South America. Specimens of <em>S. brasiliensis</em> were collected from the Miranda River in the Brazilian Pantanal, with a prevalence of the infection of 63.6 % (7/11). White and elongated plasmodia were observed in the gill filaments. Pear-shaped myxospores measured 10.1 ± 0.3 µm in length, 6.6 ± 0.3 µm in width, and 5.1 ± 0.1 µm in thickness. Nematocysts were elongated and occupied more than half of the spore body, measuring 4.9 ± 0.3 µm in length and 1.9 ± 0.2 µm in width. Histopathological analysis revealed plasmodia developing in the epithelial tissue at the distal ends of the gill filaments, resulting in compression of adjacent tissues and structures. A thin connective tissue capsule surrounded the plasmodia, and numerous granulocytic cells were observed in the tissue adjacent to the plasmodia. Sequencing of the small subunit ribosomal DNA (SSU rDNA) yielded a 1954 bp fragment. Phylogenetic analysis showed <em>M. mirandensis</em> grouping with <em>Myxobolus oliveirai</em> and <em>Myxobolus filamentum</em>, both reported in Bryconidae hosts. This represents the seventh record of a myxozoan infecting <em>S. brasiliensis</em>.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"272 ","pages":"Article 107931"},"PeriodicalIF":2.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145676165","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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