Rubella virus spreads by close contact with infected individuals who are infectious for a week before the rash appears and at least four days afterwards. It used to occur in epidemics (see EPIDEMIC) every three years or so, predominantly in the winter and spring but this pattern is not seen once sufficient number of children are immunised. One attack gives permanent IMMUNITY. The incubation period is usually 14–21 days.

are usually mild with headache, CATARRH with sneezing, coughing, sore throat and mild fever. The glands of the neck become enlarged and within 24 hours a pink, slightly raised rash appears, first on the face or neck, then on the chest, and the second day spreads all over the body. The clinical signs and symptoms of many other viral infections are indistinguishable from rubella so a precise diagnosis cannot be made without taking samples (such as saliva) for antibody testing, but this is rarely done in practice.

Around 20% of children whose mothers were infected with rubella during the first three months of pregnancy are born with CONGENITAL defects including low birth weight with retarded physical development; malformations of the HEART; cataract (see under EYE, DISORDERS OF); and DEAFNESS.

There is no specific treatment. Children who develop the disease should not return to school until they have recovered, and in any case not before four days have passed from the onset of the rash.

Women in the first 16 weeks of pregnancy should avoid all contact. If they are in contact, then they are likely to be recommended to receive an intramuscular injection of GAMMA-GLOBULIN.

In the United Kingdom it is NHS policy for all children to have the combined measles, mumps and rubella vaccine (see MMR VACCINE), subject to parental consent. All women of childbearing age, who have been shown by a simple laboratory test not to have had the disease, are offered rubella vaccine, provided that the woman is not pregnant at the time and has not been exposed to the risk of pregnancy during the previous eight weeks.