Toxoplasma gondii prevalence in Chinese avian species: A narrative review

Abstract

Toxoplasma gondii (T. gondii) is a neurotropic apicomplexan protozoan that infects a diverse range of hosts, posing a significant health risk to ~one-third of the global population. In most cases, infection remains asymptomatic, with clinical manifestations primarily observed in immunocompromised individuals and pregnant women. Avian species serve as intermediate hosts that may facilitate the spread of T. gondii to humans and carnivorous animals. This review presents a comprehensive summary of the prevalence and epidemiological characteristics of T. gondii in avian species across China, focusing on associated risk factors. To identify studies on T. gondii infection in avian species in China, a comprehensive literature search was conducted across six electronic databases, including PubMed, Science Direct, Web of Science, Wanfang, China National Knowledge Infrastructure, and Weipu. After screening the full texts, 38 articles covering tissue or serum samples from 24,397 chickens, 2,939 ducks, 1,159 geese, 640 pigeons, and 1,869 other avian populations were included in this review. The average detection rates of this pathogen were 13.85% (3,380/24,397) in chickens, 9.19% (270/2,939) in ducks, 6.56% (76/1,159) in geese, 11.25% (72/640) in pigeons, and 14.83% (277/1,869) in other avian species. Moreover, factors such as age and breeding models appeared to be associated with variations in the prevalence of T. gondii among Chinese chicken populations. This review demonstrates a high prevalence of T. gondii among avian species in China, indicating a considerable risk of zoonotic transmission and highlighting the potential role of birds in spreading the infection across multiple host species.