Study of the Seasonal and Geographical Prevalence of Toxoplasma gondii in milk of ruminants by nested-PCR

Toxoplasmosis is one of the most dangerous common protozoan diseases between humans and animals that infect humans in various ways. Contact with the infected animal, consuming contaminated food, and transmitting from mother to fetus is the most important means of transmission. Based on the recorded data, this study is the first report of Toxoplasma gondii in buffalo and camel milk in some parts of Iran. For this purpose, 440 raw milk samples of 5 species of animals were collected from Isfahan, Chaharmahal & Bakhtiari, Khuzestan, and Fars provinces during four seasons and studied for the presence of Toxoplasma gondii by nested-PCR. The results showed that 26 (5.9%) of the samples were infected with Toxoplasma gondii. The highest infection was observed in sheep milk (8%) and the lowest in buffalo milk (4.28%). The seasonal prevalence of infection was in winter (11.43%), autumn (6.8%), and spring (5.03%), while none of the samples obtained in summer the parasite was not infected. Contamination of raw milk and traditional dairy products with Toxoplasma gondii can either occur directly from infected animals or as a result of non-compliance with the principles of hygiene during the process of milking, transportation, storage, and cross-contamination. Therefore, proper pre-consumption of milk is recommended.