What is the rubella virus?

Rubella virus is a single-stranded positive-sense RNA virus belonging to the family Togaviridae and is the causative agent of rubella. Biologically, it belongs to the genus Rubivirus within the arthropod-borne viruses and infects only humans. The virus is primarily transmitted via droplets, with the most contagious period occurring several days before, during, and after the rash appears. After the virus enters the human body, the incubation period is usually 14–21 days, after which symptoms such as fever, sore throat, cough, and swollen, tender lymph nodes develop, followed by red maculopapular rashes appearing on the face and behind the ears. Rubella virus can cause vertical transmission; if a pregnant woman becomes infected early in pregnancy, it may lead to miscarriage, fetal malformations, or congenital rubella syndrome. Additionally, the rubella virus has poor viability outside the host and is sensitive to heat, ultraviolet light, and other environmental factors.