Chemoprophylactic praziquantel treatment in experimental hydatidosis

In the present study, new data on the chemoprophylactic treatment of experi mental hydatid disease with praziquantel are presented. In vivo studies hav e been performed reducing the treatment to 1 and 2 months. NMRI female mice inoculated with pro toscolices of Echinococcus granulosus were treated wit h praziquantel 48 h p.i. at a dose of 600 mg/kg, 5 days a week for 1 or 2 m onths. After 4 months p.i, the animals were killed, and the cysts obtained were counted, weighed and processed for observations by means of transmissi on electron microscopy. Both wet weight and number of hyaline cysts found i n treated mice were significantly lower than those found in control groups in both experiments (1 and 2 months of treatment), obtaining a high efficac y in all cases. Moreover, severe ultrastructural damage in the treated cyst s was seen compared to the control cysts. The reduction in treatment time l ays the basis for an important advance in the control and prevention of hyd atidosis.