Equine infectious anemia on Marajo Island at the mouth of the Amazon river

Abstract: Equine infectious anemia (EIA) is a transmissible and incurable disease caused by a lentivirus, the equine infectious anemia virus (EIAV). There are no reports in the literature of this infection in Equidae on Marajo Island. The objective of this study was to diagnose the disease in the municipalities of Cachoeira do Arari, Salvaterra, Santa Cruz do Arari and Soure, on Marajó Island, state of Pará, Brazil. For serological survey samples were collected from 294 horses, over 5-month-old, males and females of puruca and marajoara breeds and from some half-breeds, which were tested by immunodiffusion in Agar gel (AGID). A prevalence of 46.26% (136/294) positive cases was found. EIA is considered endemic in the municipalities studied, due to the ecology of the region with a high numbered population of bloodsucking insect vectors and the absence of official measures for the control of the disease.