Prevalence of Bovine Brucellosis in Islamabad and Rawalpindi Districts of Pakistan

A study was conducted to determine the prevalence of Brucella abortus in cattle and buffaloes in the districts of Islamabad and Rawalpindi, Pakistan. A total of 120 serum samples were randomly collected from buffaloes and cattle (60 per species) at Civil Veterinary Hospitals, animal markets and peri-urban livestock holdings in Rawalpindi and Islamabad. Serum samples were initially screened by the Rose Bengal Plate Test (RBPT). RBPT positive samples were subjected to a B. abortus specific indirect enzyme-linked immunosorbent assay (i-ELISA). Serum samples that were confirmed to be positive for B. abortus through serology were subjected to an rPCR in order to test its efficacy in detecting Brucella in blood of infected animals. Initially a Brucella genus-specific bcsp31 genomic region based rPCR was used. This was followed by two species-specific rPCRs that detected IS 711 genomic region of B. abortus and B. melitensis. Five (8.3%) serum samples from cattle and 1 from buffalo (1.6%) were found to be positive for B. abortus by RBPT. Four (6.6%) out of the 5 RBPT positive cattle samples were also found to be positive by i-ELISA, while one was negative in i-ELISA. The single RBPT positive buffalo was also positive in i-ELISA. Brucella genus specific rPCR amplification occurred in all the 5 seropositive samples. In the species-specific rPCR B. abortus was detected in all the samples.