Emergence and pandemic spread of small ruminant lentiviruses.

Small ruminant lentiviruses (SRLVs) cause chronic, persistent infections in populations of domestic sheep () and goats () worldwide. The vast majority of SRLV infections involve two genotypes (A and B) that spread in association with the emergence of global livestock trade. However, SRLVs have likely been present in Eurasian ruminant populations since at least the early Neolithic period.