Authors

J Webster¹;  ¹ Royal Veterinary College, UK

Discussion

Since 2021 we have seen the launch of a new WHO Neglected Tropical Diseases (NTD) Roadmap, together with revised Disease Control and Elimination Guidelines and Targets. Across all there is now a clear emphasis on the need to incorporate a One Health approach, recognizing the critical links between human and animal health and the environment. Schistosomiasis is a NTD of global medical and veterinary importance, with over 220 million people currently infected as well as untold millions of livestock. Despite over two decades of mass administration of the anthelmintic praziquantel to, predominantly, school-aged children, the burden of schistosomiasis remains extremely high in certain regions. Whilst animal hosts have been long acknowledged as zoonotic reservoirs across Asia, within Africa or the Americas, in contrast, any zoonotic component of schistosomiasis transmission and its implications for disease control has, until now, been largely ignored. This is true of both S. mansoni, but also notably, S. haematobium, the latter of which was assumed to be an exclusively human infection – and thus amenable to elimination by targeting treatment of humans alone. However, an increasing body of work has revealed widespread viable hybridization between S. haematobium of humans with Schistosoma spp. (notably S. bovis, S. curassoni or S. mattheii) of livestock throughout Africa and beyond. The dynamics of which species/species-combination predominates varies focally. Moreover, whilst recent genomic evidence suggests the majority of such hybrids may be ancient, there is also evidence of rare ongoing contemporary hybridization. Here I will present some of our recent research focusing on the transmission dynamics of Schistosoma spp. – notably that of the potential risk raised by ongoing viable hybridization between Schistosoma species of both humans and animals.