Seasonal variation in occurrence of Coxiella burnetii infection in buffaloes slaughtered in India

Molecular and serological screening of coxiellosis in bovines with reproductive disorders in dairy farms

Coxiella burnetii infection is an emerging/re-emerging public health problem affecting several countries worldwide. In India, the disease is mainly underdiagnosed, creating hindrances in its effective control. This study investigated the occurrence of C. burnetii among apparently healthy cattle and cattle with a history of reproductive disorders by both PCR and indirect-ELISA. A total of 731 clinical samples (serum: 531, and vaginal swabs as well as blood: 100 each) from 531 cattle were screened for coxiellosis. The serum, blood, and vaginal swabs each collected from 100 cattle with a history of reproductive disorders were screened using Com1-PCR, Trans-PCR, and indirect-ELISA. Conversely, serum samples obtained from apparently healthy cattle were exclusively screened using indirect ELISA. None of the samples tested could detect C. burnetii in PCR assays, while 13.37 % of serum samples were found to be seropositive in i-ELISA. Seropositivity noted among clinically healthy and those suffering from reproductive disorders were 12.76 % and 16 %, respectively, exhibiting a non-significant difference observed between these two categories. The obtained results suggested that the occurrence of coxiellosis did not differ significantly between clinically healthy animals and those with reproductive disorders; hence, in farms affected with C. burnetii infection, screening healthy and symptomatic animals is crucial to implement appropriate preventive measures.

Coxiella burnetii in cattle and their human contacts in a gaushala (cattle shelter) from India and its partial com1 gene sequence-based phylogenetic analysis

Q fever caused by Coxiella burnetii is an important zoonosis and has great public health significance. A total of 905 clinical samples from 387 cattle [serum (n = 387); vaginal swabs (n = 387); milk (n = 131)] and 59 serum samples from humans were collected from gaushala (cattle shelter) and screened for anti-C. burnetii IgG antibodies in the sera using an indirect-ELISA kit. Further, the samples were tested for C. burnetii DNA employing TaqMan real-time and conventional PCR assays targeting the com1 gene. In ELISA, 9.56% and 6.78% of animal and human sera samples were positive for anti-C. burnetii antibodies, respectively. Upon pathogen detection, 3.87% sera, 1.81% vaginal swabs, and 6.87% milk samples from cattle tested positive in TaqMan real-time PCR and 1.55% sera, 0.52% vaginal swabs, and 3.05% milk samples were found positive in conventional PCR. In humans, one serum sample was positive in both the PCR assays. The PCR positive samples (n = 12) were partially sequenced and the phylogenetic tree was constructed using com1 gene sequences (n = 42) from a different host and geographical areas. The study highlights infection of cattle and their human contacts in gaushala and identifies relationships between strains identified in the gaushala and those in other parts of the globe.