The occurrence of maedi-visna virus in Lebanon.

Maedi-visna (MV) is a chronic viral disease prevalent in adult sheep that is caused by a virus belonging to the small ruminant lentivirus group (SRLV). This disease is considered to affect the international trade of sheep and is classified in the World Organisation for Animal Health (OIE) list of notifiable animal diseases. Although maedi-visna virus (MVV) has been detected in many countries, no study on its occurrence has been carried out in Lebanon. For this purpose, a serological survey of infection with MVV was conducted in seven of the eight Lebanese governorates using a competitive enzyme-linked immunosorbent assay (ELISA). A total of 184 individual blood samples from sheep of the local breed 'Awassi', originating from 16 farms distributed throughout the seven Lebanese governorates, were collected and analysed. Among the 184 tested sheep, 131 sheep from the16 farms visited were MVV positive. This presents a prevalence of 71% MVV-positive animals and 100% MVV-positive farms. The results indicate the need for further systematic investigations into the between-herd and within-herd prevalence of MV in Lebanon.