Prevalence of anti-Coxiella burnetii antibodies and associated risk factors in bovine dairy farms of Jammu, India

Abstract

Background: Coxiella burnetii, the causative agent of Q fever, is an important zoonotic pathogen. Dairy cattle act as reservoirs, shedding the organism through milk, birth products, and excreta, thereby contaminating the environment and facilitating transmission. Aim: This study aimed to determine the prevalence of anti-Coxiella burnetii antibodies at the herd level among bovine dairy farms in Jammu district, Jammu and Kashmir, India, and to identify associated farm-level risk factors. Methods: In this cross-sectional study (January–May 2022), 360 bulk-tank milk samples were collected from bovine dairy farms using proportionate stratified sampling based on the regional bovine population distribution. Anti-C. burnetii antibodies were detected using a commercial indirect ELISA kit for bovine milk samples. Data regarding farm management, reproductive health, hygiene, and biosecurity practices were collected using a structured questionnaire. Univariable and multivariable logistic regression analyses were performed to identify factors associated with positivity to C. burnetii antibodies. Results: Overall, 93 of 360 farms were positive (25.83%; 95% CI: 21.39–30.68%), with the high prevalence in Bishnah (46.43%), Akhnoor (36.73%), and R.S. Pura (28.00%). The univariable analysis identified several factors associated with anti-C. burnetii antibody positivity, including semi-intensive and stall-fed production systems, shared watering systems, poor drainage, on-farm waste disposal, tick infestation, mastitis, abortion history, premature stillbirth, retained placenta, and sale and purchase of bovines. In contrast, the odds of anti-C. burnetii antibody positivity were lower with regular deworming, routine veterinary health monitoring, hand hygiene, and changing clothes during animal handling. In the multivariable analysis, poor drainage system (AOR: 2.94), tick infestation (AOR: 3.41), abortion history (AOR: 8.87), premature stillbirth (AOR: 3.22), retained placenta (AOR: 2.06), on-farm waste disposal (AOR: 1.98), and sale and purchase of bovines (AOR: 1.94) remained independent predictors of anti-C. burnetii antibody positivity, whereas regular deworming (AOR: 0.13) and routine veterinary health check-ups (AOR: 0.42) were independently associated with lower odds of anti-C. burnetii antibody positivity. Conclusion: The findings indicate widespread herd-level exposure to C. burnetii in Jammu dairy farms and underscore the need for strengthened farm biosecurity and One Health surveillance.