First Report of Seroprevalence in Slaughter Pigs in Shandong Province, Eastern China.

, a kind of obligate intracellular Gram-negative bacteria, can infect humans and animals worldwide, including pigs. However, the information on infection is unavailable in pigs in Shandong province, eastern China. To assess the seroprevalence and risk factors of infection in pigs in Shandong province, eastern China, a total of 2108 serum samples of slaughter pigs were collected between January 2017 and December 2018, and specific antibodies against were detected by the indirect hemagglutination assay. The overall seroprevalence was 24.15% (509/2108, 95% confidence interval: 22.32-25.97). Species, sampling regions, and rearing systems of pigs were considered as risk factors for infection through statistical analysis by SAS analysis ( < 0.05). These results indicated that is highly prevalent in slaughter pigs in Shandong province, eastern China, and may pose a potential risk for human health. To our knowledge, this is the first investigation of seroprevalence in slaughter pigs in Shandong province, eastern China. Moreover, this is the first report to compare the seroprevalence between domestic pigs and farmed wild boars in a same study, which may provide important data for preventing and controlling infection in pigs in China.