02676nas a2200289   4500000000100000008004100001260003700042653001600079653002600095653001500121653001600136653001800152100001100170700001400181700001400195700001100209700001500220700001700235700001200252700001800264245012700282856008900409300000700498490000600505520186100511022001402372       2025                            d  bPublic Library of Science (PLoS)10aSchistosoma10aOccupational Exposure10abiocontrol10arice fields10afish species 1 aSack A1 aSelland E1 aBakhoum S1 aSeck M1 aJouanard N1 aMagblenou LD1 aRohr JR1 aBroadhurst MJ00aHuman Schistosoma exposure risk in rice fields and an exploration of fish species for snail and schistosomiasis biocontrol  uhttps://journals.plos.org/globalpublichealth/article?id=10.1371/journal.pgph.0004726  a160 v53 a<jats:p>Schistosomiasis is a devastating parasitic disease in which the infectious stage to humans is released by intermediate host snails. The Senegal River Basin (SRB) is a high-risk area for both urogenital and fecal human schistosomiasis and has extensive rice cultivation. However, occupational risk of schistosomiasis to people working in irrigated rice fields is not well established. We performed intermediate host snail surveys from 2022-2023 in rice fields and irrigation canals throughout the SRB. We discovered human schistosome-shedding snails in rice fields and adjacent irrigation canals during the rice growing and non-growing seasons, establishing a clear occupational exposure risk to rice farmers. Relative to the non-growing season, this risk was higher in the rice growing and harvest season when more people are in the rice fields. Rice-fish co-culturing might reduce this occupational risk to rice farmers if local fish species consume enough snail intermediate hosts to reduce <jats:italic>Schistosoma</jats:italic> transmission. Our predation trials revealed that local <jats:italic>Heterotis niloticus</jats:italic> and <jats:italic>Hemichromis</jats:italic> spp. fish consumed significant numbers of <jats:italic>Biomphalaria pfeifferi</jats:italic> and <jats:italic>Bulinus</jats:italic> spp. snails, and separate trials revealed that these same snail species exhibited only moderate avoidance and refuge use responses to fish chemical cues. These results indicate that there is exposure to <jats:italic>Schistosoma</jats:italic> parasites in rice fields in the SRB and introducing local fish to rice fields has promise for reducing this exposure as well as providing a protein source to rice farming families. We encourage future studies to more fully explore the benefits of rice-fish co-culturing in the West Africa.</jats:p>  a2767-3375