Distribution of Toxoplasma gondiiTissue Cysts in Shoulder Muscles of Naturally Infected Goats and Lambs

Toxoplasmosis has been recognized as a major public health problem worldwide. The consumption of uncooked or undercooked meat infected with Toxoplasma gondiitissue cysts is one of the main means of transmission of this parasite. Although sheep, goats, and pigs are commonly infected with T. gondii,little information is available on the distribution of T. gondiitissue cysts in naturally infected meat. In this study, we investigated the distribution of viable T. gondiitissue cysts in shoulder muscles of naturally infected lambs and goats. Hearts and shoulders of 46 lambs and 39 goats from a local grocery store were tested for T. gondiiinfection. Animals were evaluated for the presence of anti–T. gondiiantibodies in heart blood and clots by the modified agglutination test. Fourteen of the 85 animals (seven lambs and seven goats) were seropositive. Six to 12 samples weighing 5, 10, and 50 g were obtained from shoulder muscles of each seropositive animal and used for bioassay in mice. The distribution of viable T. gondiidiffered according to the size of the sample analyzed, but in general larger sample sizes resulted in higher isolation rates (P< 0.05). Results of the study revealed an uneven distribution of T. gondiiin muscle samples of lambs and goats and that T. gondiican be transmitted by consumption of very small servings (5 and 10 g) of meat when it is consumed raw or is undercooked.