Rubella is an infectious disease that is caused by rubella virus infection. The incubation period for rubella is usually 14-18 days. Rubella is contracted through inhalation of infectious large particle aerosols, so close prolonged contact with an infected person increases the chance of infection. The virus initially replicates in nasopharyngeal cells and regional lymph nodes. Viremia develops 5-7 days after infection and the virus spreads throughout the body via the bloodstream. During this period, virus can be isolated from the pharynx and blood, and sometimes subsequently from many other sites, including synovial fluid, urine, bronchoalveolar lavage fluid, and cerebrospinal fluid. Infected individuals can excrete the virus 1-2 weeks before the onset of overt clinical symptoms and are potentially infectious. In many cases, rubella infection is asymptomatic, and therefore, viral excretion and infectiousness in infected individuals is never recognized. IgG antibodies produced after rubella infection provide immunoprotection, but reinfection can still occur. Upon re-exposure to the virus, titers of pre-existing antibodies are markedly elevated, but viremia is rarely detectable or poses little risk to the developing fetus. Still, a few cases of fetal infection following reinfection of the mother with rubella have been reported. Treatment is supportive and there is no specific treatment for rubella infection. Rubella vaccination is intended to prevent congenital rubella infection. At least one dose of live attenuated rubella vaccine is recommended for all individuals aged 12 months and older.