Screening for brucellosis in dairy cattle

Brucellosis was a zoonotic disease and constitutes serious public health hazard. The study was conducted to assess the prevalence of brucellosis in dairy cattle and to compare different screening tests for detection of brucellosis in dairy cattle. About 62 crossbred dairy cattle from different private farms in Wayanad district were utilized for the study. The animal details including breed and lactation were recorded. About 5 ml each milk and blood was collected from these animals. Milk was subjected to milk ring test (MRT) and serum was subjected to different screening tests like rose bengal plate test (RBPT) and lateral flow assay (LFA). Out of 62 milk samples tested 14 samples were found to be positive for MRT. The prevalence was found to be zero (0/62), 4.8(3/62), 11.3(7/62), 6.5(4/62) and zero (0/62) per cent in 1st, 2nd, 3rd, 4th and 5th lactation respectively. One serum sample was found to be positive for both MRT and RBPT, but gave a negative result to LFA, so the sensitivity of this test might be less than that of RBPT and MRT. However, an accurate estimation of sensitivity and specificity of different diagnostic tests requires true status of the disease using gold standard test.