ABSTRACT
Eighty white rats were infected with 1000 larvae of Trichinella spiralis/rat. Serum samples and the hearts of infected animals were taken weekly for 20 weeks after infection. Tissues from the heart were stained with hematoxylin and eosin and Mallory stains to demonstrate histopathological changes and with peroxidase anti- peroxidase for the detection of specific antigen deposition. Early in the disease, myocardial changes were detected. Later on, pericarditis and interstitial myocarditis were found followed by patchy myocardial necrosis and fibrosis. Antigen deposition was demonstrated mainly on sarcolemmal sheath of myocardial muscle fibers and in endothelial cell lining of blood vessels. No larvae were found in heart sections throughout the study. The pathological changes were mainly attributed to the antigen deposition and subsequent immune reaction