Measles Overview

Causes

Measles is caused by a virus. The infection is spread by contact with droplets from the nose, mouth, or throat of an infected person. For example, sneezing and coughing can put contaminated droplets into the air. Symptoms occur generally 8 to 12 days after you are exposed to the virus. This is called the incubation period.

Persons with the measles typically have a fever , cough , redness and irritation of the eyes ( conjunctivitis ), and a rash that spreads. Those who have had an active measles infection or who have been vaccinated against the measles have immunity to the disease.

Before widespread immunization, measles was so common during childhood that most people became sick with the disease by age 20. While the number of measles cases dropped over the last several decades to virtually none in the U.S. and Canada, rates have started to ...