Seroprevalence of Chlamydophila abortus infection in yaks (Bos grunniens) in Qinghai, China

Chlamydophila abortus is an important amphixenosis which in a wide range of animals, associated with reproductive disorders in yaks. In order to assess the prevalence of this infection in yaks in Qinghai, China, a cross-sectional study was carried out, and a total of 674 serum samples were collected from June to October 2012 in six counties, and antibodies to C. abortus were examined by indirect hemagglutination (IHA) test. The overall seroprevalence of C. abortus in yaks was 17.66 % (119/674), and the seroprevalence of antibodies to C. abortus in yaks ranged from 11.82 to 28.43 % among the six different areas, and the difference was statistically significant (P < 0.05). The seropositivity of C. abortus infection in different age groups varied from 16.33 to 18.49 %, and prevalence in yaks of ≥3 year (18.49 %) was slightly higher than that in yaks of <3 year, but the differences among the age groups were not statistically significant (P > 0.05). The seroprevalence of C. abortus infection in male yak (16.8 %) was slightly lower than that in females (17.85 %), and the difference was not statistically significant (P > 0.05). So far, this is the first systematic and comprehensive investigation of C. abortus infectionin in yaks in this area.