Experimental trichinosis: effect of immunosuppression on the host-parasite system.

Experimental trichinosis in immunocompetent verus immunosuppressed albino rats was studied over a period of two months. The immunosuppressed ones showed significant delay in expulsion of adult worms, significant increase in the yield of muscle larvae, lower IFA titres and delayed encystation of muscle larvae with mild cellular infiltration. Specific antigen deposits detected in the muscles and different tissues of the immunosuppressed rats indicated augmentation of circulating antigens. In both groups, the liver, kidney, lung, brain and testes showed nonspecific pathological changes but larvae were never detected in examined sections. Incidentally, on the 14th post-infection day, two immunocompetent rats were found pregnant, and near-full-term embryos showed more deposition of Trichinella antigens in most of their tissues indicating placental passage of circulating antigens. This study indicates that in patients receiving immunosuppressive drugs, possible exposure to T. spiralis infection will result in severe manifestations or complications.