Chemotherapy of experimental echinococcosis in mice

Mebendazole and flubendazole, administered in food at 500 ppm for 14 consecutive days, had a marked effect on one-year-old hydatid cysts of Echinococcus granulosus in mice infected with protoscolices of human origin. In both treated groups most of the cysts were collapsed compared with none in the controls. A small number of apparently viable cysts was observed in both mebendazole and flubendazole treated mice. Histological examination of collapsed cysts revealed necrosis and limited inflammatory infiltration, but in one intact cyst a normal germinal layer was present. The body weight decrease of the treated mice, as the cysts collapsed, was interpreted as an excellent indicator of drug efficacy. Drug-related side effects were not observed.