Presenter of 2 Presentations
SCHISTOTOMIASIS RESERVOIR HOSTS IN WESTERN AFRICA (ID 1759)
Abstract
Abstract Body
Over the past year 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, caused by Schistosoma spp. trematodes, 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, particularly within sub-Saharan Africa. Whilst animal hosts are acknowledged as zoonotic reservoirs across Asia, within Africa, in contrast, any zoonotic component of schistosomiasis transmission and its implications for disease control has, until now, been largely ignored. This is particularly the case for S. haematobium, the causative agent of urogenital schistosomiasis in humans, which was assumed to be an exclusively human infection – and thus amenable to elimination by targeting treatment of humans alone. Here we will illustrate the transmission dynamics of Schistosoma spp., and notably the emerging risk raised by ongoing viable hybridization between Schistosoma species of both humans and animals. Such research emphasizes that a truly multi-disciplinary One Health perspective must be implemented in order to achieve the 2030 WHO Roadmap targets of elimination of schistosomiasis as a public health problem and ultimately towards interruption of transmission.
POPULATION GENOMIC ANALYSES OF ENDEMIC SCHISTOSOMA MANSONI REVEALS EXTENSIVE TRANSMISSION AND RECENT HYBRIDIZATION (ID 1894)
Abstract
Abstract Body
Mass-drug administration (MDA) using praziquantel monotherapy has become the primary strategy for the control and elimination of the neglected tropical disease schistosomiasis. To understand how long-term MDA is impacting the transmission and evolution of schistosome populations, we analysed whole-genome sequence data of 574 Schistosoma mansoni and S. rodhaini accessions from eight countries. We observed high genetic diversity and widespread transmission of S. mansoni lineages within and between major foci of infection. Within Lake Victoria, a transmission hotspot, we found evidence of recent hybridization between the human- and rodent-infective S. mansoniand the rodent-infective S. rodhaini, with indications of introgression of S. rodhaini alleles into S. mansoni populations. Analysis of candidate praziquantel resistance loci identified several rare and low-frequency variants, predicted to reduce praziquantel sensitivity, in population sampled from regions of long-term MDA. Our findings provide insights into the genomic composition of endemic populations and should help inform genomic surveillance of this major human parasite.