STATEN ISLAND, N.Y. -- The Centers for Disease Control and Prevention (CDC) is investigating over 100 cases of measles in 21 states, including New York.
There have been 107 people who have contracted the measles, the CDC reported.
The disease has been reported in Arkansas, California, Connecticut, Florida, Illinois, Indiana, Kansas, Louisiana, Maryland, Michigan, Missouri, Nevada, New Jersey, New York, North Carolina, Oklahoma, Oregon, Pennsylvania, Tennessee, Texas, and Washington and the District of Colombia.
Many of the people who contracted the measles were not vaccinated. However, it hasn't been confirmed if the cases were linked to those without the vaccination.
Measles is a highly contagious virus that lives in the nose and throat mucus of an infected person. It can spread to others through coughing and sneezing.
The virus can live for up to two hours in an airspace where the infected person coughed or sneezed.
It's so contagious that if one person has it, 90 percent of the people close to that person who aren't immune will also become infected.
Infected people can spread measles to others from four days before through four days after the rash appears.
Symptoms include high fever, runny nose, cough, red eyes and a rash that starts on the face and then spreads. In severe cases, patients develop pneumonia and brain swelling.
Measles can be serious for people of all ages, but is especially dangerous for those younger than five years of age and adults older than 20.
The disease is still common in many parts of the world, including Europe, Asia, the Pacific and Africa.
Travelers continue to bring the disease into the U.S. It spreads when it reaches a community in the country where groups of people are not vaccinated.