Clinical case report of brucellosis in horses in an area under control strategies from the Mexico-united states border region

An outbreak of brucellosis occurred in the municipality of Victoria, in the state of Tamaulipas, Mexico. On 25 April 2010, in a stable with 16 riding horses, a mare presented weakness, progressive emaciation, difficult movements and suppurative fistulous withers. Serum samples of these horses and other 27 horses in close contact with animals of the affected stable were subjected to the Rose Bengal test with 8% cell concentration and Rivanol test for identifying the presence of antibodies against Brucella abortus strain 1119-3, and microbiological culture. Since only the mare with fistulous withers was positive, the attack rate was 6.25% and was associated with the geographical origin of the mare (Prevalence ratio = 15.00, P = 0.444) and females (Prevalence ratio = 31.952, P = 0.801). Control measures of the outbreak were implemented on 26 April 2010 and they included euthanizing and incineration of the positive mare, complete cleaning and disinfection of all boxes and objects that were in close contact with the positive mare, strict quarantine of the affected stable and epidemiological surveillance. Epidemiological surveillance consisted in screening all horses and the four people who were in close contact with the positive mare, with RBT every two weeks. After the two months of surveillance, none of the serum samples were seropositive, so the outbreak was controlled and the stable was free of the disease.