morbillivirus

Morbillivirus is a genus in the family Paramyxoviridae, subfamily Orthoparamyxovirinae, within the order Mononegavirales. It comprises several viral species that infect mammals and are genetically related by their negative-sense, single-stranded RNA genomes and enveloped virions.

Virions are enveloped and pleomorphic, with a nonsegmented negative-sense RNA genome of about 15 to 16 kilobases. The genome encodes the nucleocapsid (N), phosphoprotein (P), matrix (M), fusion (F) and hemagglutinin (H) glycoproteins, and the large (L) polymerase, with additional V and C proteins produced through RNA editing and editing-dependent reading-frame shifts. The H and F glycoproteins mediate receptor binding and membrane fusion during entry.

Members of Morbillivirus include the measles morbillivirus (humans), canine distemper virus (CDV) affecting dogs and many carnivores, rinderpest virus (RPV) in cattle (eradicated in 2011), peste-des petits ruminants virus (PPRV) in small ruminants, and marine-mammal morbilliviruses such as phocine distemper virus. Transmission is primarily via respiratory droplets, with initial replication in the respiratory tract followed by viremia and, in many hosts, systemic disease. Immunosuppression is a common feature, contributing to secondary infections and complications.

Diagnosis relies on molecular methods such as RT-PCR and serology. Vaccination programs exist for several Morbillivirus members (notably measles in humans and vaccines for CDV and PPRV in animals), and successful eradication of RPV demonstrates the potential for disease control. Surveillance and vaccination remain central to preventing outbreaks across susceptible species.