The effect of controlled release copper sulfate and tributyltin fluoride on the mortality and infectivity of Schistosoma mansoni miracidia

Abstract

Experiments were conducted to assess the effect of sublethal concentrations of controlled release copper sulfate (EC-8) and tributyltin fluoride (CBL-9B) on the mortality and infectivity of Schistosoma mansoni miracidia. It was found that LC50 and LC90 of EC-8 to the miracidia were 8.5 mg/l per hr and 15.75 mg/l per hr respectively. For CBL-9B, LC50 was 19.75 microgram/l per hr and LC90 was 32.0 microgram/l per hr. Exposing the miracidia to 0.5 mg/l of EC-8 or 4.0 microgram/l of CBL-9B respectively, for only one hour can prevent their transmission to the snail host. The results indicate that immobilization of the free living stages of the schistosome parasite was not required to interrupt their transmission to the next hosts.