Seroprevalence of Toxoplasma gondii infection in yaks ( Bos grunniens ) in northwestern China

The seroprevalence of Toxoplasma gondii infection in yaks ( Bos grunniens ) was surveyed in Qinghai Province, northwestern China in May and June 2010. A total of 650 serum samples were collected from six counties and assayed for T . gondii antibodies by an indirect hemagglutination test. Antibodies to T . gondii were found in 35.08% (228/650) with the highest rate of 55.34% in Chengduo County. The results of the present survey indicated that infection with T . gondii in cattle is widely spread in China, including yaks in Qinghai Province.