What is it?
Rubella, once also called German measles or three-day measles, is a contagious viral infection best known by its distinctive red rash.
Rubella is not the same as measles (rubeola), though the two illnesses do share some characteristics, including a red rash. However, rubella is caused by a different virus and is neither as infectious nor usually as severe as measles.
The signs and symptoms of rubella are often so mild that they're difficult to notice, especially in children. If signs and symptoms do occur, they generally appear between two and three weeks after exposure to the virus. They typically last about two to three days and may include:
- Mild fever of 102 F (38.9 C) or lower
- Stuffy or runny nose
- Inflamed, red eyes
- Enlarged, tender lymph nodes at the base of the skull, the back of the neck and behind the ears
- A fine, pink rash that begins on the face and quickly spreads to the trunk and then the arms and legs, before disappearing in the same sequence
- Aching joints, especially in young women
The cause of rubella is a virus that's passed from person to person. It can spread when an infected person coughs or sneezes, or it can spread by direct contact with an infected person's respiratory secretions, such as mucous. It can also be transmitted from a pregnant woman to her unborn child via the bloodstream. A person with rubella is contagious from 10 days before the onset of the rash until about one or two weeks after the rash disappears.
Rubella is rare in the United States because most children receive a vaccination against the infection at an early age. However, cases of rubella do occur, mostly in unvaccinated foreign-born adults.
The disease is still common in many parts of the world, although more than half of all countries now use a rubella vaccine. The prevalence of rubella in other countries is something to consider before going abroad, especially if you're pregnant.
Rubella is a mild infection. Once you've had the disease, you're usually permanently immune. Some women with rubella experience arthritis in the fingers, wrists and knees, which generally lasts for about one month. In rare cases, rubella can cause an ear infection (otitis media) or inflammation of the brain (encephalitis).
However, if you're pregnant when you contract rubella, the consequences for your unborn child may be severe. Up to 85 percent of infants born to mothers who had rubella during their first 11 weeks of pregnancy develop congenital rubella syndrome. This can cause one or more problems, including:
- Growth retardation
- Congenital heart defects
- Defects in other organs
- Mental retardation
The highest risk to the fetus is during the first trimester, but exposure later in pregnancy also is dangerous.
The rubella rash can look like many other viral rashes. So doctors usually confirm rubella with the help of laboratory tests. You may have a virus culture or a blood test, which can detect the presence of different types of rubella antibodies in your blood. These antibodies indicate whether you've had a recent or past infection or a rubella vaccine.