Seroprevalence of Chlamydia abortus infection in Tibetan sheep in Qinghai Province, China.

Chlamydia abortus (C. abortus) is an obligate intracellular, Gram-negative bacterium, causing ovine enzootic abortion (OEA). No data about C. abortus infection are available in Tibetan sheep in Qinghai, China. A total of 1043 Tibetan sheep serum samples were collected from 8 regions in Qinghai, China, and for specific antibodies against C. abortus using a commercial ELISA Kit. The results showed that the overall seroprevalence of C. abortus in Tibetan sheep was 153/1043 (14.7 %, 95 % confidence interval [CI] 12.5-16.8). The prevalence in female and male Tibetan sheep was 58/421 (13.8 %, 95 % CI 10.5-17.1) and 95/622 (15.3 %, 95 % CI 18.6-26.6), respectively with no significant difference (P > 0.05). The seroprevalence of antibodies to C. abortus in Tibetan sheep ranged from 10.0 to 21.7 % among the eight different areas, and the difference was also without statistical significance. The prevalence among different age groups ranged from 14.0 to 16.5 %, with a higher prevalence among 1 to 1.5 years age category. The results demonstrate the presence of C. abortus infection in Tibetan sheep in Qinghai and its potential impact on public health and the local Tibetan economy. To our knowledge, this is the first seroprevalence survey of C. abortus in Tibetan sheep in Qinghai, China.