RubellaVirus

Rubellavirus, commonly referred to as rubella virus, is a member of the genus Rubivirus in the family Matonaviridae. It is the etiologic agent of rubella in humans and is typically transmitted via respiratory droplets. The virus is enveloped and possesses a positive-sense, single-stranded RNA genome, with surface glycoproteins that mediate attachment and entry into host cells.

The genome is approximately 9.8 kilobases long and encodes structural and nonstructural proteins required for replication. Rubellavirus replicates in the cytoplasm of infected cells and can be shed before the appearance of rash, making control of transmission challenging in susceptible populations.

Clinical features vary by age. In children, rubella often presents as a low-grade fever, malaise, postauricular and suboccipital lymphadenopathy, and a fine maculopapular rash that lasts about three days. Arthralgia or arthritis is more common in adults, particularly women. A key concern is congenital rubella syndrome (CRS), which occurs when infection happens during pregnancy, especially in the first trimester. CRS can cause sensorineural deafness, cataracts, heart defects, microcephaly, and other developmental anomalies, and can result in fetal loss.

Diagnosis relies on serology to detect rubella-specific IgM or IgG antibodies and on molecular methods such as RT-PCR to detect viral RNA in clinical specimens. Virus isolation is rarely performed in routine practice.

Prevention is primarily through vaccination with rubella-containing vaccines, typically given as part of the MMR or MR vaccines. Widespread vaccination has reduced rubella incidence and CRS, with several regions achieving regional elimination. There are no widely used antiviral therapies for rubella.