Epidemiological investigation and reinfection evaluation of Toxoplasma gondii in chickens in Shandong Province, China.

Toxoplasma gondii infects almost all warm-blooded animals, and toxoplasmosis is a common zoonotic parasitic disease worldwide. A nested PCR with high specificity and sensitivity was developed in this study based on the data collected on the infection rate of toxoplasmosis in chickens in Shandong province, and the effect of low temperature on the infectivity of tachyzoites was investigated. The sampling data showed that the total prevalence of T. gondii in Shandong province was 12.3%, and the positive rate varied in different regions, ranging from 6.7% to 21%. Chickens were infected with T. gondii under laboratory conditions, and positive chicken hearts were stored under various cold conditions to infect mice for reinfection evaluation. The results demonstrated that the parasites maintained high infectivity in mice even after 6 h of storage at −20 °C ambient temperature, indicating that short-term cryopreservation is not effective in reducing the risk of T. gondii transmission. These results form the basis for assessing the risk of toxoplasmosis contamination in consumed chicken products and provide information on the prevention of parasite transmission from animals to humans. [Display omitted] • The average prevalence of toxoplasmosis in chickens in Shandong province is 12.3%. • Geographical location and breeding environment are decisive factors affecting the epidemic of toxoplasmosis. • Chicken hearts infected with Toxoplasma gondii remain infectious after a short period of cryopreservation at −20 °C. [ABSTRACT FROM AUTHOR]