Evaluation of the in vivo effect of ivermectin on Schistosoma mansoni in experimentally-infected mice

Abstract

Objective: To evaluate the effect of ivermectin on mice experimentally infected with Schistosoma mansoni. Methods: Ivermectin was given to mice 42 days p.o. in two treatment regimens: a single dose of 25 mg/kg or the same dose for two consecutive days. Results: In both regimens, there were significant reductions in female worms, hepatic tissue egg count and early immature ova, in addition to significant reductions in the count and size of hepatic granuloma. The same dose for two consecutive days resulted in significant reductions in male, total worms, and intestinal tissue egg load. In both regimens, scanning electron microscopy revealed tegumental alternations as bleb formation, erosion and necrosis more evident with the double dose. In addition, high dose showed extensive erosions of male worms with destruction of the gynaecophoric canal. In females, marked destruction of the tegumental surface was extending to both ventral and oral suckers. Conclusions: Ivermectin has promising anti-schistosomal effects. However, further research is needed to test the effect of ivermectin on schistosomiasis especially in combination with other antischistosomal agents, to avoid any possible resistance from monotherapy.