An enzyme-linked immunosorbent assay (ELISA) test for the diagnosis of equine infectious anemia in Brazil

Abstract

An enzyme-linked immunosorbent assay (ELISA) test was developed for the detection of specific antibodies against the unique infectious anemia (EIA) virus in equine sera. The ELISA test was faster and more sensitive when compared with the classic test of agar gel immunodiffusion (AGID). A total of 200 sera were tested: 100 from negative horses and 100 from positive horses by AGID. The ELISA test showed 92 horse sera negative and 100 horse sera positive by AGID with values of optical density (OD) less than 0.139 and higher than 0.139, respectively. Eight horse sera were negative by AGID and higher than 0.139 by ELISA. Six of these became AGID positive also when re-tested 30 days later, and two were of the horses that showed clinical signs of EIA and died before re-testing.