Evaluation of ELISA for detection of antibodies to CAEV in milk

Milk was found to be a suitable alternative specimen for the serological diagnosis of caprine arthritis-encephalitis virus (CAEV) using the ELISA. The relative sensitivity and specificity of testing individual milk samples as compared to individual sera was 96.4 and 97.3% respectively. The overall agreement between the testing of milk and sera was 96.9% and the correlation coefficient between testing sera and milk, 0.94%. The testing of bulk milk could be used to predict approximately the prevalence of CAEV infection in a dairy goat flock. It was estimated that a prevalence of about 1.6% to 7.5% could be detected in the ELISA when bulk milk samples from two infected goat flocks were tested. Either chilled milk samples or milk samples treated with merthiolate were found to be suitable for testing.