Search

Our pilot parasitological investigation of cattle, supplemented with molecular DNA characterisation of encountered schistosomes, sheds first light upon bovine schistosomiasis on Unguja Island, Zanzibar. During February 2024, a total of 99 cattle were examined. Of these, 47 were exported animals from the Tanzanian mainland, designated for slaughter at two governmental abattoirs (Kisakasaka and Muwanda), and 52 were free-grazing animals sampled from four grazing locations within the island's North and West-B regions. Upon visual inspection of 31 cattle carcasses at Kisakasaka for adult worms, the prevalence of bovine schistosomiasis was 51.6%; however, upon faecal miracidia hatching test (MHT) it was 80.6%. At Muwanda, only faecal MHT was used, finding a much lower prevalence of 12.5%. In free-grazing animals, the prevalence of bovine schistosomiasis by MHT was 0.0%. At Muwanda, the animal quarantine paddock was in disrepair, inclusive of a large pond now acting as a watering point. Here, numerous Bulinus forskalii sp. were found. Whilst no snails were observed to shed schistosome cercariae, molecular xenomonitoring did detect a pre-patent infection prevalence of 10.8%, with Schistosoma bovis firmly incriminated. Molecular DNA characterisation of adult schistosomes (n = 19) by real-time polymerase chain reaction (PCR) and high-resolution melt profiling, alongside DNA sequencing, also identified S. bovis, although two worms were putative S. bovis-S. mattheei hybrids. Atypical intrauterine eggs of S. bovis were noted upon microscopy of a worm pair. A broader screen of 92 miracidia confirmed S. bovis and three miracidia as S. bovis-S. mattheei hybrids. Contrasting with Pemba Island, Zanzibar, where autochthonous transmission of S. bovis can occur, bovine schistosomiasis on Unguja Island currently appears restricted to imported animals alone. However, the seminal detection of putative S. bovis-mattheei hybrids, alongside the current inadequate quarantine facilities at Muwanda, raises a new concern that such hybrid schistosomes may escape and enter the island's hinterland. Should this happen, surveillance and control of urogenital schistosomiasis on Unguja would be compromised and further complicated. We therefore strongly recommend immediate repair and improved maintenance of governmental animal quarantine facilities. Future epidemiological surveys of imported cattle are now well justified, not only to better understand the full repertoire of hybrid schistosomes present but also to develop appropriate mitigating interventions., Competing Interests: Declarations. Ethics approval and consent to participate: Schistosome surveillance is within a governmental mandate of the Zanzibar Ministry of Health. All cattle sampling used non-invasive faecal collection methods, and protocols were approved by the animal ethics committee of the Zanzibar Livestock Research Institute. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Background: Intestinal schistosomiasis was confirmed endemic in Mangochi District, Malawi, in May of 2018 following an unexpected encounter with discreet populations of Biomphalaria spp. freshwater snails during routine malacological surveillance activities. Since then, only limited malacological surveillance of Biomphalaria has been carried out, and so the distribution of Biomphalaria populations in this area is currently unclear. Additionally, sites of active Schistosoma mansoni transmission in this area are also unknown. In the present study, through extensive malacological surveillance, we aimed to formally document the distribution of Biomphalaria in Mangochi District. We also aimed to identify active intestinal schistosomiasis transmission sites in this area through subjecting all collected Biomphalaria to a recently developed S. mansoni-specific molecular xenomonitoring PCR., Methods: Three malacological surveys were carried out along the southern shoreline of Lake Malawi, Mangochi District, Malawi, in November 2021, July 2022 and October/November 2022. All collected Biomphalaria were subjected to cercarial shedding analysis to identify active Schistosoma infections. Shed cercariae were then genotyped to species level using a standard multi-locus PCR and Sanger sequencing protocol. Following this, a subset of Biomphalaria from each collection site were also genotyped to species level using a standard PCR and Sanger sequencing protocol. All collected Biomphalaria were then subjected to a recently developed S. mansoni-specific molecular xenomonitoring PCR to identify infected, but non-shedding, Biomphalaria., Results: A total of 589 Biomphalaria were collected across all three surveys. One single Biomphalaria (0.17%) specimen was found to be actively shedding Schistosoma cercariae, which were molecularly confirmed as S. mansoni. All genotyped Biomphalaria (n = 42) were molecularly identified as B. pfeifferi. A further 19 Biomphalaria specimens, collected from four different surveillance sites, were found to be infected with S. mansoni through molecular xenomonitoring. Intestinal schistosomiasis transmission was therefore identified at four different foci in Mangochi District., Conclusions: Our study highlights the importance of molecular approaches to investigate Biomphalaria populations and monitor Biomphalaria-associated intestinal schistosomiasis transmission in endemic areas. As such, the continued development and use of such approaches, in particular the development and use of molecular xenomonitoring assays that can be carried out in resource-poor schistosomiasis-endemic settings, is encouraged. The revision of ongoing schistosomiasis control programmes in Mangochi District, in line with WHO recommendations, is also encouraged., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. Crown.)

Starting in October 2021, quarterly malacological surveys have been undertaken in Malawi, with the sampling of 12 specified freshwater habitats throughout a calendar year. Each survey monitors the presence of aquatic intermediate snail hosts of medical and veterinary importance. In March 2023, the alien lymnaeid species Pseudosuccinea columella was encountered for the first time in the surveys, in Nsanje District. This species identity was later confirmed upon DNA analysis of mitochondrial ribosomal 16S sequences. In July 2023, P. columella was also noted at single sites within Mangochi and Chikwawa Districts, and again in Nsanje District, with an additional location observed. Of particular importance, our sampled location in Mangochi District was directly connected to Lake Malawi, which expands the species list of invasive molluscs in this lake. While P. columella is a well-known intermediate snail host for human and animal fascioliasis, screening collected snails for trematode cercariae, alongside molecular xenomonitoring, did not yield equivocal evidence of active fluke infection. However, the newly recognized presence of this alien intermediate snail host within Lake Malawi, and along the Shire River Valley, flags a new concern in altered local transmission potential for human and animal fascioliasis., (© 2024. The Author(s).)

Background: In Ghana, pre-school-aged children (PSAC) are at risk of intestinal schistosomiasis and are living in need of praziquantel treatment. To better assess the infection burden within this vulnerable demographic group, we have provided a comparative assessment of the prevalence of Schistosoma mansoni in pre-school-aged children by urine circulating cathodic antigen (CCA) dipsticks, real-time PCR Taqman® faecal assays and Kato-Katz coproscopy., Methods: In all, 190 pre-school-aged children were sampled from three endemic communities (viz. Tomefa, Torgahkope/Adakope, and Manheam) around Weija dam, Southern Ghana. Fresh stool and urine samples were collected from all participants for diagnosis., Results: Among all the three communities, the urine-CCA assay recorded the highest prevalence values of 90.5% (95% CI 80.4-96.4), 87.9% (95% CI 76.7-95), and 81.2% (95% CI 69.9-89.6) in Tomefa, Torgahkope/Adakope, and Manheam respectively. Prevalence by real-time PCR was 50% (95% CI 35.5-64.5), 8% (95% CI 2.2-19.2) and 16.7% (95% CI 8.3-28.5), while by Kato-Katz was 55.6% (95% CI 42.5-68.1), 8.6% (95% CI 2.9-19) and 11.6% (95% CI 5.1-21.6) respectively. Children aged 1 year and over were found to be positive with the urine-CCA assay; by the ages of 3-4, over 50% were urine-CCA patent. The sensitivity and specificity of the POC-CCA dipsticks, when compared against the combined results of Kato-Katz/TaqMan results was found to be 84.1% (95% CI = 72.7-92.1) and 12.9% (95% CI = 6.6-22) respectively., Conclusions: We propose that the urine-CCA dipstick may be a useful rapid diagnostic tool to estimate the prevalence of intestinal schistosomiasis in PSAC, particularly in rapid identification of at-risk areas. However, our assessment has shown that it possible to record false positives when compared to combined Kato-Katz and qPCR results. To guide PSAC praziquantel treatment needs, we propose the urine CCA assay should be included in routine surveillance of intestinal schistosomiasis alongside other diagnostics such as Kato-Katz and urine filtration.

Background: Hymenolepis microstoma (Dujardin, 1845) Blanchard, 1891, the mouse bile duct tapeworm, is a rodent/beetle-hosted laboratory model that has been used in research and teaching since its domestication in the 1950s. Recent characterization of its genome has prompted us to describe the specific strain that underpins these data, anchoring its identity and bringing the 150+ year-old original description up-to-date., Results: Morphometric and ultrastructural analyses were carried out on laboratory-reared specimens of the 'Nottingham' strain of Hymenolepis microstoma used for genome characterization. A contemporary description of the species is provided including detailed illustration of adult anatomy and elucidation of its taxonomy and the history of the specific laboratory isolate., Conclusions: Our work acts to anchor the specific strain from which the H. microstoma genome has been characterized and provides an anatomical reference for researchers needing to employ a model tapeworm system that enables easy access to all stages of the life cycle. We review its classification, life history and development, and briefly discuss the genome and other model systems being employed at the beginning of a genomic era in cestodology.