What is Measles?
Measles is a highly contagious viral infection that spreads from person-to-person. A person with measles can spread the disease to others even before they have any symptoms. Most people who have not been immunized against measles will get it if they have contact with the virus.
Measles is spread through a cough or sneeze by a person with measles and can still infect others 2 hours after the infected person has left a room. Persons with measles are contagious from 4 days before until 4 days after the rash appears. The incubation period for developing measles is up to 21 days after being exposed to someone else who has the disease.