Diseases & Conditions
Rubella (German measles, 3-day measles) is a contagious viral infection that produces mild symptoms, such as joint pain and a rash.
Rubella is a typically mild childhood infection that may, however, have devastating consequences for infants infected before birth. A woman infected during the first 16 weeks (particularly the first 8 to 10 weeks) of pregnancy often passes the infection to the fetus. This fetal infection causes miscarriage, stillbirth, or severe birth defects (see Birth Defects: Introduction ).
Rubella was once common during the springtime, with major epidemics every 6 to 9 years infecting millions of people. The disease is now rare in the United States because of widespread vaccination. Nonetheless, some young adult women have never had rubella or rubella vaccination and are thus at risk of having children with serious birth defects if they become infected during early pregnancy.
Rubella is spread mainly by breathing in small virus-containing droplets of moisture that have been coughed into the air by an infected person. Close contact with an infected person can also spread the infection. The infection may be contagious from 7 days before until 14 days after the rash appears, although usually the period of maximal contagiousness is from a few days before symptoms begin until the rash disappears. An infant infected before birth can spread the infection for many months after birth.
Symptoms and Diagnosis
Symptoms begin about 14 to 21 days after infection. Some children feel mildly ill for a few days, with a runny nose, cough, and painless, rose-colored spots on the roof of the mouth. These spots later merge with each other into a red blush extending over the back of the throat. In most children, particularly older ones, the first sign of illness is the development of swollen lymph nodes in the neck and back of the head. A characteristic rash develops about a day later and lasts about 3 to 5 days. The rash begins on the face and neck and quickly spreads to the trunk, arms, and legs. As the rash appears, a mild reddening of the skin (flush) occurs, particularly on the face.
Adults, usually women, may develop arthritis or joint pain with rubella. In rare instances, a middle ear infection (otitis media) develops. Brain infection (encephalitis) is a very rare but occasionally fatal complication.
The diagnosis is based on the typical symptoms. A definite diagnosis, necessary during pregnancy, can be made by measuring levels of antibodies to rubella virus in the blood.
Prevention and Treatment
Rubella vaccine, one of the routine immunizations of childhood, is given beginning at 12 months of age (see Vaccinating Infants and Children ). A person who has had rubella develops immunity and cannot contract it again.
Most children with rubella recover fully without treatment. A middle ear infection can be treated with antibiotics. No treatment is available for encephalitis, which must just run its course with supportive care.
Last full review/revision May 2007 by Mary T. Caserta, MD
Source: The Merck Manual Home Edition