Background and Aim: Q fever is a worldwide zoonosis caused by the intracellular bacterium, Coxiella burnetii. A few studies focused on the occurrence of Q fever infection in water buffaloes in Thailand have been conducted; however, little is known regarding the seroprevalence of C. burnetii antibodies in buffaloes. In the present study, we describe the prevalence of Q fever infection in water buffaloes (Bubalus bubalis) in Phatthalung, Thailand.

Materials and Methods: A total of 421 samples (156 blood, 156 sera, and 109 ectoparasites [lice]) were collected from 156 water buffaloes from 29 farms of the Phatthalung Province from January 22, 2021, to March 26, 2021. The blood and ectoparasite samples were screened for C. burnetii DNA using a polymerase chain reaction assay and the sera were tested for C. burnetii antibody using an indirect immunofluorescence assay.

Results: C. burnetii DNA was not detected in blood or ectoparasites; however, the seroprevalence of individual water buffaloes was 4.49% (95% CI: 2.19-8.99%), whereas that of the herd was 13.79%. There was a significant difference between abortion history and Q fever infection at 29 farms (p=0.005; OR=33.55 [95%CI: 156-722.38]).

Conclusion: This is the first report describing the low seroprevalence of C. burnetii antibodies in water buffaloes in Phatthalung Province, Thailand. The occurrence of this pathogen in buffaloes with reproductive disorders and people working with buffaloes warrant further investigation. Animal health authorities should inform farmers to effectively prevent and control this zoonosis.

Keywords: Coxiella burnetii, indirect immunofluorescence assay, Q fever, seroprevalence, Thailand, water buffaloes.