Brucella abortus infection in a multispecies livestock farm in Nigeria

Brucellosis screening was carried out in a farm in Nigeria comprising of cattle, sheep, goats and horses reared under semi-intensive management system. Vaginal swabs and milk were cultured for Brucella isolation while sera and part of the milk were tested serologically. Brucella abortus was isolated from 2 out of 6 vaginal swabs collected from horses and from 3 out of 12 milk samples obtained from lactating cows on the farm. No Brucella was isolated from all the 10 milk samples from sheep and the 10 milk samples from goats. All sera from the 7 horses tested positive by the Rose Bengal plate test (RBPT) and serum agglutination test (SAT). Nineteen (8.34%) out of 44 sera from cattle tested positive by SAT and RBPT while 4 (12.5%) out of 32 sheep sera were positive by SAT and RBPT. Out of 50 sera from goats, 5 (10%) were positive by SAT and RBPT. Four (33.3%) of the 12 milk samples from cattle tested positive by Milk ring test while all the 10 milk samples each from sheep and goats tested negative by Milk ring test. The possible source of infection in the farm could be the cattle. It is therefore necessary to consider all species of domestic animals in brucellosis surveillance and eradication. Immediate culling of all reactors, prevention of contact between the various animal species and improvement on hygienic practices on the farm were recommended.