Chemoprophylactic praziquantel treatment in experimental hydatidosis.

In the present study, new data on the chemoprophylactic treatment of experimental hydatid disease with praziquantel are presented. In vivo studies have been performed reducing the treatment to 1 and 2 months. NMRI female mice inoculated with protoscolices of Echinococcus granulosus were treated with praziquantel 48 h p.i. at a dose of 600 mg/kg, 5 days a week for 1 or 2 months. After 4 months p.i. the animals were killed, and the cysts obtained were counted, weighed and processed for observations by means of transmission electron microscopy. Both wet weight and number of hyaline cysts found in treated mice were significantly lower than those found in control groups in both experiments (1 and 2 months of treatment), obtaining a high efficacy in all cases. Moreover, severe ultrastructural damage in the treated cysts was seen compared to the control cysts. The reduction in treatment time lays the basis for an important advance in the control and prevention of hydatidosis.