Measles was a very common childhood disease before the introduction of a vaccine in 1963. Today, there are fewer than 1,000 cases per year in the United States. The risk of exposure is much higher in other parts of the world, however.
Early symptoms of measles include fever, runny nose, cough, and sore and red eyes. This is followed by the appearance of a red-brown blotchy rash on the skin. The rash usually starts on the face and spreads downward. It lasts at least three days. Although children who get measles can become fairly sick, most of them recover with no long-term negative effects. Once in a while, measles can lead to pneumonia or encephalitis (swelling of the brain), and permanent disability or death. Adults and very young children are most severely affected.
Measles, which is caused by a virus, is preventable with a vaccine. It is usually administered as part of the MMR (measles, mumps, rubella) vaccine series, starting when children are 12 to 15 months old, with boosters at 4 to 6 or 11 to 12.
Measles is highly contagious and spreads easily when an infected person coughs or sneezes. Measles particles can stay in the air, so it's possible to get infected by being in a room where an infected person has been.