Agglutinins to Brucella abortus in horses.

The research article investigates the presence of antibodies (agglutinins) against Brucella abortus in horses. The study showed that the reduction in cases of brucellosis in cattle, due to an eradication campaign in Australia, has also led to a decline in the prevalence of these antibodies in the horse population.

Focus of the Study

• The article focuses on the variation in the prevalence of agglutinins to Brucella abortus in horses. Earlier research had shown that the prevalence was higher in horses that are in contact with dairy herds or graze on infected farms.
• The research was conducted in Australia, where an ongoing campaign was underway to eradicate brucellosis in cattle. The researchers wanted to understand if this led to a similar decrease in the horse population as well.

Methodology

• The study collected serum samples from January 1974 to August 1981 and they were examined for the presence of antibodies against B. abortus.
• The collected serums were tested using the Rose Bengal plate test (RBPT) and the serum agglutination test (SAT).
• Serums with SAT values of 80 IU/ml or more were considered positive.

Findings

• Out of a total of 5,424 serums collected, 38 were RBPT positive and 37 were SAT positive.
• The data collected indicated a significant reduction in the prevalence of agglutinins in horses compared to a survey conducted from 1963 to 1966.
• The overall prevalence of agglutinins has fallen from 1.9% to 0.7%, a reduction of 64% compared to the earlier data.
• In the serums collected at Camden, the reduction was from 2.5% to 1.0%, or 62%.

Additional Observations

• The study observed that the reduction was primarily due to a decrease in the number of cases of fistulous withers, a swelling condition in horses often linked with B. abortus infection.
• Previous research established a link between fistulous withers and B. abortus, with the current findings providing further confirmation.
• Interestingly, it was noted that 2.0% of brood mares tested had agglutinins, that is a slightly higher percentage than in the overall horse population.
• Last, but not least, the decline in the presence of antibodies against B. abortus suggests the measures to get rid of brucellosis in cattle may have a beneficial impact on the horse population as well.