Rubella is a contagious infectious disease caused by a single-stranded, enveloped RNA virus in the family Togaviridae and the genus Rubivirus.

• In 2012, there were 94,030 cases of rubella worldwide, although this figure is probably an underestimate because of poor reporting. Since 2004, rubella has not been an endemic disease in the United States.
• Virus is spread via respiratory droplets, and primary implantation and replication occur in the nasopharynx. Placental infection can lead to chronic infection of virtually all fetal organs, which sometimes persists for up to 1 year after birth.