First serologic survey of Q fever in free range yaks in China

The objective of the present investigation was to determine the seroprevalence of Coxiella burnetii infection in free range yaks in China. A total of 552 serum sles were collected from yaks in Gansu province, northwest China between April 2013 and January 2014, and antibodies against C. burnetii were evaluated using enzyme linked immunosorbent assay (ELISA). Overall, 13.59% (75/552, 95% CI: 10.73 16.45) of the examined animals were positive for C. burnetii antibodies. There was no significant difference in C. burnetii seroprevalence between female yaks (13.78%, 95% CI: 10.36 17.19) and male yaks (13.13%, 95% CI: 7.89 18.36) (P 0.05). Coxiella burnetii seroprevalence in yaks in different age groups ranged from 10.88% to 15.26%, but the difference was not statistically significant (P 0.05). Coxiella burnetii seroprevalence in yaks sled in different seasons ranged from 12.06% (autumn) to 18.33% (summer), but the difference was not statistically significant (P 0.05). This is the first report of C. burnetii seroprevalence in free range yaks in China, indicating the need for measures to be taken to control C. burnetii infection in free range yaks in China.