Classification of peste des petits ruminants virus as the fourth member of the genus Morbillivirus.

Peste des petits ruminants (PPR) is a virus disease of sheep and goats in West Africa. When first described, the virus was considered a variant of rinderpest virus. The biological and physicochemical characteristics of the virus indicate that it is closely related to measles, rinderpest and canine distemper viruses. These three viruses form the genus Morbillivirus of the Paramyxoviridae. PPR virus is sufficiently distinct from these 3 viruses to justify considering it as the fourth member of the Morbillivirus genus.