Current research in parasitology & vector-borne diseases最新文献

{"title":"New insights into the genetic diversity, phylogeny, and immunogenic potential of the wsp gene in Wolbachia endosymbionts in Brugia malayi and Brugia pahangi","authors":"Witchuta Junsiri ,&nbsp;Piyanan Taweethavonsawat","doi":"10.1016/j.crpvbd.2025.100272","DOIUrl":"10.1016/j.crpvbd.2025.100272","url":null,"abstract":"<div><div><em>Wolbachia</em> spp. are intracellular, maternally inherited bacteria that infect a wide range of arthropods. These bacteria influence reproductive traits in their hosts and are used in mosquito-borne virus control programmes. This study investigates the <em>Wolbachia</em> surface protein (WSP), a potential trigger of innate immune responses. The <em>wsp</em> gene was amplified by polymerase chain reaction, cloned, and sequenced. Phylogenetic analysis showed that <em>wsp</em> sequences from <em>Wolbachia</em> endosymbionts of <em>Brugia pahangi</em> and <em>B. malayi</em> formed two clades within the supergroup D. The <em>wsp</em> sequences were highly conserved, with 99–100% sequence identity across global isolates. Haplotype analysis revealed 13 distinct <em>wsp</em> haplotypes. The average antigenic score of the WSP protein was 1.029 for <em>B. malayi</em> and 1.026 for <em>B. pahangi</em>. MHC-NP analysis predicted eight antigen ligands for <em>B. malayi</em> and six for <em>B. pahangi</em>. Notably, a shared antigen ligand (VIADQKHGF) was identified for both species, associated with dog leukocyte antigens (DLA-8850101, DLA-8803401, and DLA-8850801). Additionally, a conserved ligand region (ALVMLLSLSNSAFSD) was identified in the WSP of <em>B. malayi</em>, corresponding to human leukocyte antigens (HLA-DR alleles HLA-DRB1∗04:04 and HLA-DRB1∗04:01). These findings provide new insights into the phylogenetic classification, sequence conservation, and immunogenic potential of the WSP protein in <em>Wolbachia</em> endosymbionts of <em>Brugia</em> spp.</div></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"7 ","pages":"Article 100272"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144138938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deciphering a cryptic minefield: A guide to Cryptosporidium gp60 subtyping","authors":"Guy Robinson ,&nbsp;Rachel M. Chalmers ,&nbsp;Kristin Elwin ,&nbsp;Rebecca A. Guy ,&nbsp;Kyrylo Bessonov ,&nbsp;Karin Troell ,&nbsp;Lihua Xiao","doi":"10.1016/j.crpvbd.2025.100257","DOIUrl":"10.1016/j.crpvbd.2025.100257","url":null,"abstract":"<div><div>For 25 years, analysis of the <em>gp60</em> gene has been the cornerstone of <em>Cryptosporidium</em> subtyping, particularly for <em>Cryptosporidium hominis</em> and <em>Cryptosporidium parvum</em>, during population-based and epidemiological studies. This gene, which encodes a 60 kDa glycoprotein, is highly polymorphic with several variable features that make it particularly useful for differentiating within <em>Cryptosporidium</em> species. However, while this variability has proven useful for subtyping, it has on occasion resulted in alternative interpretations, and descriptions of novel and unusual features have been added to the nomenclature system, resulting in inconsistency and confusion. The components of the <em>gp60</em> gene sequence used in the nomenclature that are discussed here include “R” repeats, “r” repeats, alphabetical suffixes, “variant” designations, and the use of the Greek alphabet as a family designation. As the subtyping scheme has expanded over the years, its application to different <em>Cryptosporidium</em> species has also made the scheme more complex. For example, key features may be absent, such as the typical TCA/TCG/TCT serine microsatellite that forms a major part of the nomenclature in <em>C. hominis</em> and <em>C. parvum</em>. As is to be expected in such a variable gene, different primer sets have been developed for the amplification of the <em>gp60</em> in various species and these have been collated. Here we bring together all the current components of <em>gp60</em>, including a guide to the nomenclature in various species, software to assist in analysing sequences, and links to useful reference resources with an aim to promote standardisation of this subtyping tool.</div></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"7 ","pages":"Article 100257"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the epidemiological impact of attractive targeted sugar bait against malaria in combination with standard malaria control","authors":"Nima R. Moghaddas ,&nbsp;Mohamed M. Traore ,&nbsp;Gunter C. Müller ,&nbsp;Joseph Wagman ,&nbsp;Javan Chanda ,&nbsp;Julian Entwistle ,&nbsp;Christen M. Fornadel ,&nbsp;Thomas S. Churcher","doi":"10.1016/j.crpvbd.2025.100247","DOIUrl":"10.1016/j.crpvbd.2025.100247","url":null,"abstract":"<div><div>Attractive targeted sugar bait (ATSB) is a potential new vector control tool that exploits the sugar-feeding behaviour of mosquitoes. Little is known about the factors which drive ATSB efficacy, either as a standalone vector control tool or in combination with existing intervention strategies. It has been suggested that the percentage of wild mosquitoes caught fed on dye-containing sugar baits without the toxin could provide an entomological correlate of the potential epidemiological benefit of ATSB. A transmission dynamics mathematical model is combined with data from wild mosquitoes to investigate the relationship between the mosquito dyed fraction, bait-feeding rate and the potential epidemiological impact of ATSB in the presence of standard malaria control. The dyed fraction in Mali varies substantially in space and time (mean 0.34, standard deviation 0.15), causing estimates of the bait-feeding rate to be highly uncertain, especially in areas with existing vector control tools. The model indicates the dyed fractions observed in field experiments were broadly predictive of the reductions in mosquitoes caught when ATSB stations were deployed at scale in Mali (<em>R</em>² = 0.90). Model projections suggest that if these bait-feeding rates were observed in all mosquitoes, then the widespread use of ATSB could substantially reduce malaria burden alone or in combinations with standard malaria control, though epidemiological impact is likely to vary substantially in different areas. For example, observing a dyed fraction of 5% would indicate a daily bait-feeding rate of 0.024 (range 0.008–0.049) which is projected to result in 0.13 clinical cases averted per person-year (range 0.051–0.22), a 39% efficacy (range 12–66%) in this particular site. Nevertheless, the uncertainty in the relationship between the observed dyed fraction and the true bait-feeding rate, and the underlying biology of mosquito sugar-feeding means that the epidemiological benefit of this new possible intervention remains unclear.</div></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"7 ","pages":"Article 100247"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143378485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Species classification of Tabanus (Diptera: Tabanidae) in Western Thailand: Integrating DNA barcoding and modern morphometrics","authors":"Tanasak Changbunjong ,&nbsp;Thekhawet Weluwanarak ,&nbsp;Sedthapong Laojun ,&nbsp;Tanawat Chaiphongpachara","doi":"10.1016/j.crpvbd.2025.100243","DOIUrl":"10.1016/j.crpvbd.2025.100243","url":null,"abstract":"<div><div>The species of <em>Tabanus</em>, commonly known as horse flies, are remarkable ectoparasites capable of transmitting various pathogens to animals and humans. Given their role in disease transmission, accurate identification of horse fly species is critical but traditionally relies on morphological characteristics, requiring significant expertise and posing a high potential for error, especially with damaged specimens. To address the limitations of traditional morphological identification, this study highlights the importance of alternative techniques, including DNA barcoding and geometric morphometrics (GM). To enhance the reliability of species identification, DNA barcoding was employed to analyze 30 cytochrome <em>c</em> oxidase subunit 1 (<em>cox</em>1) gene sequences from 15 horse fly species, which were then compared with sequences in the GenBank and BOLD databases. Most <em>cox</em>1 sequences aligned with existing data, with similarity percentages ranging from 96% to 100%. However, discrepancies were noted, including <em>Tabanus helvinus</em>, misidentified as <em>Tabanus aurilineatus</em>, and <em>Tabanus minimus</em>, whose sequences matched those of both <em>Tabanus minimus</em> and <em>Tabanus mesogaeus</em>. Besides DNA barcoding, GM analyses were conducted to enhance species classification accuracy. Our GM analyses employed the landmark-based method for the entire wing and the outline-based method for the first submarginal cell. While shape-based GM analyses demonstrated high reliability, with adjusted total accuracy scores of 97% and 96%, size-based GM analyses yielded significantly lower accuracy, with scores of only 27% and 23%, respectively. These findings provide a foundation for refining horse fly species classification by integrating DNA barcoding and GM approaches, offering valuable advances in species identification and developing targeted control measures.</div></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"7 ","pages":"Article 100243"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143346095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genome analyses of amphotericin B-susceptible and -resistant strains of Leishmania (Mundinia) martiniquensis reveal variations potentially related to amphotericin B resistance","authors":"Narissara Jariyapan ,&nbsp;Sivamoke Dissook ,&nbsp;Pitiporn Noisagul ,&nbsp;Patcharawadee Thongkumkoon ,&nbsp;Chonlada Mano ,&nbsp;Romteera Kittichaiworakul ,&nbsp;Anuluck Junkum ,&nbsp;Adisak Tantiworawit ,&nbsp;Pascale Pescher ,&nbsp;Gerald F. Späth ,&nbsp;Hatim Almutairi ,&nbsp;Padet Siriyasatien","doi":"10.1016/j.crpvbd.2025.100255","DOIUrl":"10.1016/j.crpvbd.2025.100255","url":null,"abstract":"<div><div>Amphotericin B deoxycholate (AmpB) is used for the treatment of leishmaniasis caused by <em>Leishmania</em> (<em>Mundinia</em>) <em>martiniquensis</em> in Thailand, and relapse cases have been documented. To date, genomic analysis of drug-resistant <em>L</em>. <em>martiniquensis</em> strains is limited. In this study, comparative genome analyses were performed with an experimentally selected AmpB-resistant <em>L</em>. <em>martiniquensis</em> (AmpBRP2i) and two cryopreserved <em>L</em>. <em>martiniquensis</em> parasite strains isolated from a patient showing differences in response to AmpB treatment, LSCM1-WT (susceptible) and LSCM1-6 (resistant). Applying the GIP genome analyses package, we identified aneuploidy and gene copy number variations in all three samples, none of which correlated with AmpB resistance. In contrast, single nucleotide variant (SNV) analyses revealed an SNV in AmpB-resistant strains introduced a premature stop codon into a putative sterol C-24 reductase gene (<em>C24R</em>) (<em>LSCM1_02556</em>) involved in the ergosterol biosynthetic pathway in <em>Leishmania</em>. As <em>Leishmania</em> AmpB resistance has previously been linked to mutations in other genes of the ergosterol biosynthesis pathway in different species of <em>Leishmania</em> parasites, these results suggest that <em>C24R</em> may serve as an additional marker of AmpB resistance in <em>Leishmania</em>. We further identified two missense SNVs in AmpB-resistant strains in a putative ‘ABC transporter-like/ABC transporter family’ gene (<em>LSCM1_01856</em>) that could be involved in drug efflux. These initial findings pave the way for future research with a larger number of isolates to confirm the genomic signature we associate here with AmpB resistance.</div></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"7 ","pages":"Article 100255"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Redefining Rhipicephalus sanguineus (sensu lato) species complex in Greece focusing on the mitogenome of Rhipicephalus secundus","authors":"Panagiota Ligda ,&nbsp;Jan Šlapeta ,&nbsp;Anastasios Saratsis ,&nbsp;Vaia Kantzoura ,&nbsp;Jaisy Chong ,&nbsp;Smaragda Sotiraki","doi":"10.1016/j.crpvbd.2024.100231","DOIUrl":"10.1016/j.crpvbd.2024.100231","url":null,"abstract":"<div><div><em>Rhipicephalus sanguineus</em> species complex, referred to as <em>R. sanguineus</em> (<em>sensu lato</em>), is distributed globally with some species distributed in specific regions and others spread globally. In Greece, <em>R. sanguineus</em> (<em>s.l.</em>) in dogs, and <em>Rhipicephalus turanicus</em> and <em>Rhipicephalus bursa</em> in livestock, have been repeatedly reported however only based on morphological identification. Recently, there has been a great effort to accurately identify the species belonging to the <em>R. sanguineus</em> species complex, using modern molecular tools and describe their spatial distribution. The aim of this study was to expand the studies on the molecular characterisation of species of the <em>R. sanguineus</em> (<em>s.l.</em>) complex in the Mediterranean region, by molecularly characterising ticks collected from various locations and host species in Greece. Results confirm the presence of <em>Rhipicephalus rutilus</em>, <em>Rhipicephalus secundus</em>, <em>R. bursa</em>, and <em>R. turanicus</em>. The complete mitochondrial genome of <em>R. secundus</em> (approx. 15 kb) from sheep (<em>n</em> = 3) in Greece was sequenced and matched to sequences and morphological data from the type-material from Israel. Additionally, the mitogenome of <em>R. bursa</em> from goats (<em>n</em> = 2) in Greece was sequenced. This study provides a molecular reference for <em>R. secundus</em>, a tick species distributed in the Eastern Mediterranean region.</div></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"7 ","pages":"Article 100231"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11696630/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142934335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Malaria transmission, insecticide resistance and efficacy of insecticide-treated nets in Belabo and Ouami, two localities of the East Region of Cameroon","authors":"Paulette Ndjeunia-Mbiakop ,&nbsp;Idriss Nasser Ngangue-Siewe ,&nbsp;Abdou Talipouo ,&nbsp;Arnold Princewil Chi Nji ,&nbsp;Roland Bamou ,&nbsp;Joel Djoufounna ,&nbsp;Jeannette Tombi ,&nbsp;Christophe Antonio-Nkondjio","doi":"10.1016/j.crpvbd.2025.100266","DOIUrl":"10.1016/j.crpvbd.2025.100266","url":null,"abstract":"<div><div>The East Region of Cameroon has over 150 malaria cases per 1000 inhabitants per year. Factors contributing to this high malaria prevalence are not well understood. This study assessed the bionomics of vectors involved in malaria transmission, their susceptibility to insecticides, and the efficacy of insecticide-treated nets. Entomological studies were conducted twice yearly in Belabo and Ouami from 2021 to 2023 using both human landing catches and CDC light traps to collect adult mosquitoes. Anopheline species were separated using morphological identification keys and <em>Anopheles gambiae</em> (<em>s.l</em>.) were molecularly identified to species. <em>Plasmodium falciparum</em> presence was detected by ELISA. Susceptibility of 3–5-day-old <em>An. gambiae</em> (<em>s.l.</em>) to deltamethrin, permethrin, malathion and bendiocarb was assessed. A WHO cone test was performed to assess bednet efficacy against mosquitoes. Out of 7634 mosquitoes collected, 47.44% were anophelines. <em>Anopheles gambiae</em> (<em>s.l.</em>) was the most abundant species, followed by <em>An. ziemanni</em>, <em>An. funestus</em> and <em>An. paludis</em> in both localities. The mosquito biting rate was similar in Belabo and Ouami. Both <em>Anopheles gambiae</em> (<em>s.l.</em>) and <em>An. funestus</em> were infected with <em>P. falciparum</em> at Ouami but only <em>An. gambiae</em> (<em>s.l.</em>) was infected at Belabo. <em>Anopheles gambiae</em> (<em>s.l.</em>) was less susceptible to both deltamethrin and permethrin. None of the 48 bednets tested were effective against field populations of <em>Anopheles gambiae</em> (<em>s.l.</em>) in both sites. High malaria transmission associated with high pyrethroid resistance rate was recorded in vectors from the East Region of Cameroon supporting the high endemicity of malaria in the area.</div></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"7 ","pages":"Article 100266"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144116353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transcriptome analysis of Aedes aegypti midgut and salivary gland post-Zika virus infection","authors":"Chunling Zhu ,&nbsp;Yuting Jiang ,&nbsp;Qianghui Zhang ,&nbsp;Jian Gao ,&nbsp;Chaojie Li ,&nbsp;Chunxiao Li ,&nbsp;Yande Dong ,&nbsp;Dan Xing ,&nbsp;Hengduan Zhang ,&nbsp;Teng Zhao ,&nbsp;Xiaoxia Guo ,&nbsp;Tongyan Zhao","doi":"10.1016/j.crpvbd.2025.100251","DOIUrl":"10.1016/j.crpvbd.2025.100251","url":null,"abstract":"<div><div>This study aimed to investigate the transcriptomic changes in the midgut and salivary glands of <em>Aedes aegypti</em> mosquitoes infected with Zika virus (ZIKV), in order to explore the molecular mechanisms underlying the interaction between the virus and the mosquito vector. <em>Aedes aegypti</em> from Jiegao (JG) and Mengding (MD) in China were experimentally infected with ZIKV, and the midgut and salivary gland tissues were collected at 2-, 4- and 6 days post-infection (dpi). High-throughput sequencing was performed to analyze the transcriptomic changes between ZIKV-infected and non-infected <em>Ae</em>. <em>aegypti</em> midgut and salivary gland tissues. Bioinformatics tools were employed for further analysis of the transcriptomic data. The expression levels of 8 significantly differentially expressed genes (DEGs) were validated using RT-qPCR. A conjoint analysis of small RNA-seq and mRNA-seq was performed to screen interactional miRNA-mRNA pairs during ZIKV infection. Using the Search Tool for the Retrieval of Interacting Genes, we constructed a protein-protein interaction network of genes and subsequently identified hub genes. The most significant transcriptional changes in <em>Ae</em>. <em>aegypti</em> occurred at 2 dpi. On 2, 4 and 6 dpi, 11 genes showed significant changes in both the midgut and salivary glands of the same mosquito strain, while 25 genes exhibited significant changes in the same tissue between the JG and MD strains. The expression tendencies of 8 DEGs obtained by RNA-Seq were similar to those detected by RT-qPCR. Furthermore, we individually identified 10 hub genes in the midgut and salivary glands. Based on previous miRNA research, we discovered the involvement of 9 miRNAs in the regulation of these hub genes. Our findings demonstrate that <em>Ae</em>. <em>aegypti</em> exhibit distinct transcriptomic changes in response to ZIKV infection. The identification of the hub genes and their regulatory miRNAs provides valuable insights into the molecular mechanisms underlying ZIKV infection in mosquitoes. This study contributes to a better understanding of the pathogen-vector interactions and may aid in the development of targeted strategies for ZIKV control.</div></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"7 ","pages":"Article 100251"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143644026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Entomological surveillance of onchocerciasis in Burkina Faso: Progress towards interrupting transmission in blackflies in the main river basins of the country","authors":"Lassane Koala ,&nbsp;Achille S. Nikièma ,&nbsp;Mathias Ouedraogo ,&nbsp;Justin Compaoré ,&nbsp;Clarisse Bougouma ,&nbsp;Karim Sanon ,&nbsp;Aimé G. Adjami ,&nbsp;Moussa S. Sanfo ,&nbsp;Inaki Tirados ,&nbsp;Philip McCall ,&nbsp;Paul Bessel ,&nbsp;Thomas R. Unnasch ,&nbsp;Daniel A. Boakye ,&nbsp;Soungalo Traore ,&nbsp;Roch K. Dabire","doi":"10.1016/j.crpvbd.2025.100259","DOIUrl":"10.1016/j.crpvbd.2025.100259","url":null,"abstract":"<div><div>Current guidelines for onchocerciasis elimination rely heavily upon assessment of the presence of <em>Onchocerca volvulus</em> in the vector <em>Simulium damnosum</em> (<em>sensu lato</em>). This entomological study was conducted over four years in several regions of Burkina Faso to determine the progress made towards interrupting onchocerciasis transmission. Larvae and adult blackflies were collected in eight river basins (Comoé, Léraba, Dienkoa, Mouhoun, Bougouriba, Bambassou, Nakambé, Nazinon and Sissili). Larvae were analyzed by cytotaxonomy, and the adult blackflies analyzed for the presence of infective larvae of <em>O. volvulus</em> by PCR. Blackfly infectivity rates were first determined by year for each basin, then compared to the thresholds established by the WHO. The results indicate that the blackflies collected belong to the savannah group species <em>Simulium damnosum</em> (<em>sensu stricto</em>) and <em>Simulium sirbanum</em>. Hybrids of the two species were also identified. Overall, the prevalence of flies carrying infective larvae was below the threshold of 0.05% established by the WHO, indicating important progress towards the interruption of onchocerciasis transmission in Burkina Faso, although hotspots with infectivity rates well above the WHO’s thresholds remain. <em>Onchocerca volvulus</em> continues to be transmitted in six of the nine basins evaluated, all of which border neighboring countries. These data indicate that it will be necessary to maintain entomological surveillance in these hotspot areas until transmission is interrupted throughout the region.</div></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"7 ","pages":"Article 100259"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143895790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal distribution and cercarial shedding of Bulinus spp. snails: Implications for urogenital schistosomiasis control in the Simiyu Region, northwestern Tanzania","authors":"Nyanda C. Justine ,&nbsp;Humphrey D. Mazigo ,&nbsp;Antje Fuss ,&nbsp;Bonnie L. Webster ,&nbsp;Eveline T. Konje ,&nbsp;Klaus Brehm ,&nbsp;Andreas Mueller","doi":"10.1016/j.crpvbd.2025.100248","DOIUrl":"10.1016/j.crpvbd.2025.100248","url":null,"abstract":"<div><div>Urogenital schistosomiasis is a neglected tropical disease of significant public health concern caused by the trematode species <em>Schistosoma haematobium</em>. Its transmission is localised and heterogeneous, with seasonal occurrences in Tanzania primarily facilitated by <em>Bulinus</em> spp. snails, which serve as intermediate hosts. To plan effective, data-driven control measures, it is crucial to understand the epidemiology of schistosomes in these snails. This study aimed to investigate the seasonal distribution, abundance, and <em>Schistosoma</em> spp. infections (assessed <em>via</em> cercarial emergence) in <em>Bulinus</em> spp. snails in two districts, Maswa and Meatu, in the Simiyu Region of Tanzania. Malacological surveys were conducted at 90 sites in total, comprising sites in 35 rivers, 32 ponds, and 23 branching streams. Each study site was sampled once during the rainy season and once during the dry season. Snails were collected using a standard scoop- and handpicking technique by two people for 15 min at each site. The collected snails were morphologically identified and subjected to a cercarial emergence experiment. Water physicochemical characteristics were recorded simultaneously with snail collection using a portable multiparameter water meter. The data were analysed using STATA v. 17. A total of 4997 <em>Bulinus</em> spp<em>.</em> snails were collected from 90 sites in the two districts. Of these, 91.4% (95% CI: 90.5–92.1%) were morphologically identified as <em>Bulinus nasutus</em> and 8.6% (95% CI: 7.8–9.4%) were identified as <em>Bulinus globosus</em>. <em>Bulinus</em> spp. snail abundance was almost evenly distributed across seasons, with 50.4% (95% CI: 48.9–51.7%) collected during the dry season and 49.6% (95% CI: 48.2–51.0%) collected during the rainy season. Water temperature and salinity were significantly negatively correlated with snail abundance (both <em>P</em> &lt; 0.001). <em>Schistosoma</em> spp. cercarial emergence followed a seasonal pattern and was significantly higher during the rainy season (<em>P</em> = 0.005). Our findings underscore that <em>B. nasutus</em> was the most abundant freshwater snail distributed at nearly all the study sites during the rainy and dry seasons. Therefore, appropriate snail control strategies are recommended to complement ongoing schistosomiasis control strategies in the Simiyu Region.</div></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"7 ","pages":"Article 100248"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}