Detection of small ruminant lentiviruses by PCR and serology tests in field samples of animals from Greece

Abstract

Small ruminant lentivirus (SRLV) infections have a worldwide distribution. In Greece, despite the fact that lentiviral diseases are known since 1967, SRLV genomic sequences have never been detected in field samples of infected animals. In this study, 143 animals from flocks with history of SRLV infections were analysed using ELISA, AGID, and PCR assays. None of the animals exhibited any clinical signs of the disease. ELISA had the highest sensitivity of the three assays (98.3%), but very low specificity (59%), in contrast to PCR that was highly specific (100%), but with low sensitivity (56.7%). AGID test had a good sensitivity (90%) and a very high specificity (100%). AGID failed to detect only six of the infected sheep; these were positive by PCR. This observation, suggests that the combination of AGID and PCR assays in diagnosis of Greek SRLV-strain infections may be advisable in order to achieve 100% sensitivity and specificity. In the present study we report, for the first time in Greece, PCR detection of proviral DNA in blood samples of sheep and goats from flocks with history of SRLV infections, and we compare performance of ELISA, AGID and PCR assays.