Toxoplasma infection in sheep from south of Iran monitored by serological and molecular methods; risk assessment to meat consumers

AIM: Toxoplasma gondii has a clinical and veterinary importance as it is known to cause congenital disease and abortion both in humans and livestock. Since the contaminated lamb is one of the sources of human infection, this study was performed to determine the prevalence of T. gondii in sheep in south of Iran. MATERIALS AND METHODS: Sera and tissue samples (diaphragm and heart) were collected from 370 sheep from slaughterhouse of Jahrom. The samples were taken from both sexes and from 6 to 60 months age. Specific immunoglobulin G antibodies to T. gondii were examined with enzyme-linked immunosorbent assay, and B1 gene nested-polymerase chain reaction detection was done to survey the tissue samples. RESULTS: The total prevalence of Toxoplasma infection among sheep was found to be 35.94% and 34.32% based on serological and molecular method, respectively. According to serologic and molecular findings, the females were more positive than males for Toxoplasma; maximum frequency of positive samples was observed in 24-36 months and the positive samples had been collected more in spring than in summer, but no statistical correlation was observed between prevalence rate and the age and sex of animals or season of sampling. CONCLUSION: T. gondii is widely distributed in sheep in Jahrom with a rate comparable with other parts of Iran and the world. It suggested a widespread exposure of sheep in this region to T. gondii. Thus, consumption of undercooked or raw meat presents the transmission risk of the parasite and this might be considered as an important public health problem, mainly for high-risk groups such as the pregnant and the immunodeficient.