Schistosoma mansoniBiomphalariaFasciola hepaticaTrematode InfectionsTrematodaSchistosomaSchistosoma haematobiumSchistosomiasis mansoniSchistosomiasisSnailsSchistosomiasis japonicaPraziquantelAntigens, HelminthEchinostomaParasite Egg CountHeterophyidaeSchistosomiasis haematobiaParamphistomatidaeDNA, HelminthHelminth ProteinsEchinostomiasisAnthelminticsHost-Parasite InteractionsBulinusFood ParasitologyAntibodies, Helminth