Caprine arthritis encephalitis virus diagnosed by ELISA in lactating goats using milk samples

Abstract

This study was designed to compare the ELISA method of diagnosing caprine arthritis encephalitis virus (CAEV) using two different samples: milk whey or blood samples. A commercial CAEV diagnosis kit (ELISA Kit MVV/CAEV serum monocupule, Institut Pourquier, France), was used and determination was carried out on paired samples of blood and milk from 66 lactating dairy goats of known CAEV infection status belonging to two herds. Serum samples were pre-diluted 1:20 and whey samples 1:2. All animals whose sera tested positive for the virus (37/66) also showed a positive whey sample result, and the same agreement was obtained for a negative result (29/66). In no sample was the outcome of the test dubious. Through ANOVA, it was determined that mean S/P ratios for whey (1.551 ± 1.55) and serum (1.719 ± 1.38) did not significantly differ ( P > 0.05). Our findings indicate full agreement (Kappa = 1) in terms of the two sample types producing a positive or negative result and a high correlation coefficient ( r = 0.92) between the mean S/P ratios recorded for the two data sets. In conclusion, the use of ELISA on whey samples is an appropriate method of diagnosing CAEV with its obvious benefits of non-invasive sample collection and reduced costs over traditional serological diagnosis methods. This simpler method will be especially useful for CAEV surveillance in dairy goats.