Bovine Brucellosis in Organized Farms of India - An Assessment of Diagnostic Assays and Risk Factors

Abstract

Bovine brucellosis is a highly contagious ubiquitous reproductive disorder of dairy animals. To assess the diagnostic assays and risk factors associated with bovine brucellosis, a systematic study was conducted in 24 organized farms, containing a total of 1359 dairy animals during the period of 2013-2014. Herd and animal level data were recorded in a structured questionnaire. Of the 1359 samples, 71 (5.22%), 82 (6.03%), 73 (5.37%) and 54 (3.97%) samples were positive by RBPT, iELISA, serum and blood PCRs respectively. Combination of iELISA and serum PCR were found most suitable to declare brucellosis status of the animals. The high brucellosis prevalence was recorded in medium sized farms (26-100 animals) than in small and large farms. Similarly, disease prevalence ranged from 6.13 to 11.42% in the age groups of 2 to 8 yrs. The disease predisposition with respect to breeds revealed that the prevalence varied from 3 to 5% in cross breeds of Holstein Friesian and Jersey, and serological and PCR tests were negative in Indian breeds such as Hallikar and Ongole cattle and Surti buffaloes. Purchase of animals without prior diagnosis, lack of awareness and routine milk testing were found as other potential risk factors for transmission of disease. The study facilitates improvisation of sensitivity of clinical surveillance system for early diagnosis and to prevent the disease transmission.