Brucellosis in working equines of cattle farms from Minas Gerais State, Brazil.

The research aimed to study the prevalence of brucellosis in equines (horses, mules, and donkeys) working in cattle farms in Minas Gerais, Brazil, and analyze any associated risk factors. The study found a low, but widespread prevalence of brucellosis, a bacterial infection, in these animals.

Study Methodology

• The survey conducted from September 2003 to March 2004 included 6,439 animals from 1936 herds across 848 municipalities in the state of Minas Gerais in Brazil. The subjects included different equines specifically, 5,292 horses, 1,037 mules, and 110 donkeys.
• The team searched for the presence of antibodies against smooth Brucella spp, the bacteria causing brucellosis, in the blood serum samples of these animals.

Findings

• The study estimated the prevalence of brucellosis in these animals at 1.37% with 95% confidence interval ranging between 0.97-1.78%. This means that the study authors can say with 95% confidence that the true prevalence of brucellosis amongst the equines is between 0.97% – 1.78%.
• From the herd perspective, the prevalence was 4.28%, implying that about 4.28% of the herds had at least one infected animal.

Regional Differences and Risk Factors

• While the study noticed variations between regions, they were not statistically significant, meaning that the differences could have occurred due to chance. However, it was suggested that the three northeastern regions had a slightly higher prevalence than the rest of the state.
• The study found no noticeable association of Brucella spp. seropositivity with factors like sex, age, or host, i.e., the particular type of equine.

Conclusion

• In conclusion, the researchers identified a low yet widespread occurrence of antibodies against smooth Brucella in equines working on cattle farms in Minas Gerais, a region where bovine brucellosis is also common but has a low prevalence.