Efficacy of Selected Drugs against Trichinella spiralis

Abstract

Seven drugs have been tested for efficacy against T. spiralis, namely: thiabendazole, dithiazanine-iodide, trichlorphon, hygromycin-B, dimethoate, Ruelene and American Cyanamid CL 38,023 (formerly known as Famophos). Thiabendazole, trichlorphon and dithiazanine- iodide were found to have a high degree of prophylactic activity against T. spiralis. All reduced trichinae yields in swine by more than 99.0%. Thiabendazole apparently prevented infection in four of five pigs. Hygromycin-B was ineffective as a prophylactic for swine. Ruelene and CL 38,023 possessed moderate and slight prophylactic activity, respectively, against trichiniasis in rats. In the therapeutic phase of the studies, intraperitoneal injections of trichlorphon proved completely effective against the intestinal phase of the disease in swine while treatment of the migratory phase gave a moderate reduction. A series of intraperitoneal injections against both the migratory and muscular phases gave more than 99.0% reduction in the yields. Dithiazanine-iodide demonstrated marked therapeutic efficacy against the intestinal phase with moderate effectiveness against the muscular phase. Therapeutic trials against trichiniasis in rats utilizing dimethoate, Ruelene and CL 38,023 indicated these drugs were effective only at toxic levels. The drugs were active only against the intestinal phase of the disease.