Trichinosis in Maryland raccoons

During recent studies of experimental Chagas’ disease, trichinosis was found in 2 out of a total of 44 Maryland raccoons (Procyon lotor) examined histologically following necropsy. All raccoons were trapped near the towns of Beltsville or Laurel. The raccoons found to have trichinosis were trapped in the area of the Agricultural Research Center, Beltsville. Cysts containing larvae of Trichinella spiralis were found in sections of diaphragm in one raccoon and in sections of diaphragm, skeletal muscle, and ocular muscle in the other. Three to five cysts could he seen in sections of skeletal muscle or diaphragm within a single low-power (scanning lens X 40) field. There was little if any inflammatory reaction to most of these cysts, but inflammatory cells were present adjacent to an occasional cyst (Fig. 1). Foci of calcification were found in some sections of muscle and may represent old calcified cysts.