Epidemiological Status of Equine Infeccious Anemia in Working Equidae from the Federal District, Brazil

Equine Infectious Anaemia (EIA) is a disease that has worldwide distribution and it is caused by a lentivirus. The disease constrains the development of horse breeding in Brazil, leading to compulsory slaughter of test positive animals. The objective of this study was to estimate the prevalence of EIA in traction equids and identify potential risk factors in the Federal District. Three hundred and fifty (350) owners were randomly selected (Primary Sampling Units-PSU) and all equids (Secondary Sampling Units - SSU) from each owner were sampled, in a total of 496 animals. Blood samples were tested in LANAGRO/MG using the agar-gel immunodiffusion test (AGID). An epidemiological questionnaire was used to collect data on potential risk factors associated with the disease. The prevalence of PSU (owners) was estimated at 2.29% (95% CI: 1.01-4.2%) and the prevalence in animals was 1.81% (95% CI: 0.55-3.07%). Prevalence was higher in mules than in horses. None of the other variables analyzed as potential risk factors was associated to the presence of the disease. The present study demonstrated that the prevalence of EIA in traction equids is low in the Federal District, which strengthens the case for the maintaining the test-and-cull policy and the need for disease surveillance measures aimed at eradicating the disease.