Seroprevalence and risk factors of Toxoplasma gondii infection in stray dogs in northern China.

Toxoplasma gondii is a zoonotic protozoan of almost all species of mammals and birds. However, no information is available about seroprevalence of the pathogen in stray dogs in seven cities from Inner Mongolia, Jilin, Liaoning province, China. Using the indirect hemagglutination antibody (IHA) test with a cutoff titer of 1:64, 129 (14.05 %) out of 918 stray dogs were surveyed to be T. gondii seropositive. Analysis of the risk factor showed that there was no statistical difference of seroprevalence of T. gondii between males (13.46 %) and females (14.54 %) (P > 0.05). The seropositive rates of T. gondii infection in stray dogs among the seven cities in northern China were significant statistically different (P = 0.005). Moreover, seroprevalence of T. gondii in dogs were varied from 11.01 % (95 % CI 6.94-15.09) to 16.86 % (95 % CI 12.27-21.46) among different age groups, and the difference was statistically significant (P = 0.03). More importantly, T. gondii seropositive in stray dogs has a declining tendence from 2011 to 2015 (P = 0.004). The results of the present study showed that stray dogs in Inner Mongolia, Jilin, Liaoning province, China are exposed to T. gondii, for the first time, and could also provide a foundation data for prevent and control T. gondii infection in dogs, other animals and humans.