Effect of the pesticides carbofuran [Carbamate] and Profenophos [Organophosphorus] on Biomphalaria alexandrina and on its infection with Schistosoma mansoni miracidia

Carbofuran [carbamate pesticide] and Profenophos [organophosphorus pesticide] showed molluscicidal effect on Biomphalaria alexandrina snails, with the LC[50] 1.42 ppm and 1.29 ppm, respectively Maintaining Biomphalaria alexandrina at sublethal concentrations of these compounds [0.5, 0.75, and 1.0 ppm] reduced the snail survival rate and net reproductive rate [R[0]] [E L[x]M[x]] compared with the control snail group. The percentage reduction in R[0] was 86.9, 90.8, and 93.9 for the tested concentrations of Carbofuran and 86.8, 82.9 and 88.5 for the tested concentrations of Profenophos, respectively. The susceptibility of Biomphalaria snails to infection with Schistosoma mansoni miracidia and further infectivity of this parasite were also reduced. Increasing the pesticide concentration increased the magnitude of reduction reaching 80.7% and 89.3% for the two pesticides, respectively. Pesticide may be considered one of the factors contributing in the disappearance of snail vectors on reaching water bodies as residues from pesticidal activities and consequently hindering schistosomiasis transmission