As the name implies, the rubella virus causes the disease rubella. In most cases, it is transmitted when an infected person coughs or sneezes, but it's also possible for a pregnant woman to transmit the virus to her baby if she becomes infected during pregnancy. A vaccine for the virus was first licensed in the United States in 1969. Since then, the rate of rubella infection has declined dramatically.
Rubella virus is the organism that causes rubella (also known as German measles or three-day measles). It is an RNA (ribonucleic acid) virus from the family Togaviridae and the genus Rubivirus.
The virus resides in the mucus in the nose and throat of the infected person. When that person sneezes or coughs, droplets spray into the air. The infected mucus can land in other people's noses or throats when they breathe or put their fingers in their mouth or nose after touching an infected surface.
When a person becomes infected with rubella virus, it begins to multiply within the cells that line the back of the throat and nose. The virus can also spread through the bloodstream or lymph system to other parts of the body, including the:
After 14 to 21 days, rubella symptoms can appear. This period between the transmission and the start of symptoms is called the rubella incubation period.
Though it's a mild childhood illness, rubella can pose a serious threat to the developing fetus if the mother contracts the virus during pregnancy. More than 20,000 babies were born with congenital rubella syndrome (CRS) during an outbreak of rubella in 1964-1965. This epidemic cost the country an estimated $1.5 billion. The rubella vaccine was first licensed in the United States in 1969. Since then, the number of cases has dropped sharply.