Animal Contribution To Schistosomiasis (ACTS) transmission in Benin: from epidemiological data to genomics

International audience BACKGROUND AND AIMESSchistosomiasis remains a major human and veterinary health burden in sub-Saharan Africa, and its control is challenged by the potential contribution of animal reservoir to transmission.In line with the WHO One Health roadmap for 2030, the ACTS project aims to determine the respective roles of humans, animals and the environment in the local transmission ofurogenital schistosomiasis in southern Benin (Kessounou), where Schistosoma haematobium, S. bovis, and their hybrids appear to circulate between humans, livestock and rodents. ACTS combines epidemiological surveys, population genomics, experimental infections, and mathematical modelling to assess parasite zoonotic potential and reservoir contributions.METHODSField sampling was conducted in Kessounou in June 2025. Infection prevalence was estimated using standard parasitological methods in humans, caale, and small mammals. Parasite larvae DNA were preserved on Whatman FTA Classic cards for RADseq analyses. In parallel, experimental infections of snails, rodents, and caale have been initiated to evaluate host-specific transmission competence and parasite strains development success.RESULTSPreliminary results revealed infection prevalences of 23,9% in humans and of 38,6% in caale, while no infections were detected in rodents. RAD sequencing from human and livestock samples has been completed, and genomic analyses are currently underway. A second field mission scheduled for February 2026 will capture seasonal variation in host populations and transmission paaerns, and may allow completion of RAD data from the rodent hosts.CONCLUSIONSBy integrating epidemiological, genomic, experimental, and modelling approaches, ACTS will provide critical insights into the zoonotic nature of schistosomiasis and inform controlstrategies within a One Health framework