Effect of triclabendazole on the tegument of Schistosoma mansoni: a scanning electron microscopic study.

The in vitro effect of Triclabendazole on the tegument of Schistosma mansoni was studied by means of scanning microscopy. Two different concentrations of drug were used (15 micrograms/ml and 75 micrograms/ml) and the worms examined after different exposure times (1 hr, 3 hrs, 24 hrs). It was found that, exposure of S. mansoni to Triclabendazole resulted in quick reactions: (1) The tegument was immediately destroyed after exposure in several places leading to the formation of defects in the surface of the worms. (2) The parasites contracted and became immobilized within one hour showing that the uptake of the drug was very rapid. (3) Triclabendazole caused 100% mortality after 24 hrs in the two concentrations. The ultrastructural changes were proportional to the concentration of drug and time elapsed.