Field level serodiagnosis of acute phase ovine brucellosis by OIE prescribed tests

Brucellosis in sheep caused by bacterium, Brucella ovis is characterized by decreased reproductive efficiency and abortions. Farmers of a village from YSR district of Andhra Pradesh, India, reported the history of extensive abortions in Nellore ewes, uni-orchitis in breeding rams with joint infections, swelling of male genital tracts after crossing, and reluctance to cross. Blood samples were collected from affected animals for diagnosis by using world organisation for animal health (OIE) listed field level tests like Rose Bengal Plate Agglutination Test (RBT), and Standard Tube Agglutination Test (SAT) which are suitable for acute phase infection. Screening of all flocks and other species in contact including farmers in the village by using RBT, which was negative revealed the non-transmissible ovine brucellosis caused by Brucella ovis. The positive samples from affected sheep for RBT were subjected to SAT for confirmation. Those sheep, which were positive for brucellosis based on serological tests, were culled immediately as a part of standard control measures. It can be concluded that during the acute phase, ovine brucellosis can be preliminarily diagnosed by screening test RBT at field level and further can be confirmed by SAT in the field level laboratory. Key words; Ovine brucellosis, Brucella ovis, OIE tests, RBT, SAT