Anatomical distribution of Toxoplasma gondii in naturally and experimentally infected lambs
Abstract
Consumption of raw or undercooked meat containing Toxoplasma gondii tissue cysts is one of the main source of contamination for humans world-wide. Among various species intended for human consumption, lamb appears as a risk factor of human toxoplasmosis. The present study focused on a detailed anatomical distribution of Toxoplasma gondii in naturally and experimentally infected lambs using fresh and frozen samples of various pieces of meat, from a public health perspective. Ranking the edible parts intended for human consumption, according to the parasite burden, and therefore, the risk for T. gondii contamination in human, was a first objective. A second objective was to evaluate the impact of freezing, as imports arrive mainly frozen. Viable Toxoplasma gondii tissue cysts or T. gondii DNA were present in all meat samples. High level of DNA parasite was observed in skeletal muscles and more particularly in edible portions such as quadriceps femoris, intercostal, deltoid and biceps femoris muscles with a significant difference in parasite burden between fresh and frozen samples (p < 0.0001) or natural and experimental infection (p < 0.0001). These results suggest that lamb should be thoroughly cooked or frozen before consumption. Further investigations need to be done in order to confirm the above mentioned differences in more animals and in different breeds.