Seroprevalence and molecular detection of coxiellosis among cattle and their human contacts in an organized dairy farm

Abstract

Background: The present investigation of Coxiella burnetii infection in cattle and farm workers on an organized cattle dairy farm, which appears to be the first of its kind in India, was undertaken to assess the status of this largely neglected and masked zoonosis. Methods: A total of 665 samples comprising of serum (n = 224), milk (n = 217) and vaginal swabs (n = 224) collected from milch animals (n = 224) with a history of reproductive disorders were screened. Besides these, ticks (n = 114); animal feed (n = 4) and environmental samples (n = 13) as well as serum (n = 19) of farm workers were also collected. The animal sera and milk samples as well as human sera were tested for antibodies against C. burnetii by commercial ELISA kit, whereas, all the collected samples were subjected to trans-PCR targeting the IS1111 gene of C. burnetii. Results: A high positivity for coxiellosis was detected in sera (29.91%) and milk (26.73%) samples of dairy cattle as well as sera from human contacts (84.21%) by ELISA. The trans-PCR detected the pathogen in 12.94% sera, 14.73% vaginal swabs and 5.53% milk samples of cattle, and in one soil sample, however, the sera of the farm workers and tick were tested negative. Conclusions: The high positivity for coxiellosis among cattle and farm workers highlight the need to undertake extensive epidemiological studies to unravel the trends of C. burnetii infection in India. Keywords: Coxiella burnetii, Coxiellosis, Farm workers, Organized farm, Zoonosis