Skip Ribbon Commands
Skip to main content
Health Issues

Measles: What Parents Need to Know

Measles is a fiercely contagious disease caused by the measles virus. It spreads so easily that 9 out of 10 people who are around someone with measles will catch it, too, if they are not protected.

Measles was under control in the United States, but we are seeing outbreaks again in areas where vaccination rates have fallen.

The childhood and adolescent immunization program in the United States achieved a more than 99% decrease in measles cases since 1963. However, travelers visiting or returning to the United States from other countries can spread measles to people who are at risk and cause an outbreak.

Because measles is so contagious, outbreaks happen quickly. Most of the time, children who get measles are not up to date on recommended vaccines or are not old enough to get measles vaccine.

How long is someone with measles contagious?

People with measles are contagious before they know they are sick. An infected person can spread measles easily to others 4 days before the rash appears and they are still contagious 4 days after the rash appeared.

How does measles spread?

Measles spreads from person to person and through the air from respiratory droplets from a child's cough or sneeze. The virus can live for two hours on surfaces or suspended in the air. Someone who enters a room where someone with measles had been earlier can catch the disease. The virus can also travel along air currents and infect people in another room.

Even brief exposure to the virus poses a high risk of infection to anyone who is not up to date on measles vaccine or has not had measles before. People who have conditions that weaken the immune system are also at high risk of infection.

What are the symptoms of measles?

CCommon signs of measles infection include a high fever and rash. The rash usually appears 3 to 5 days after the first symptoms. It starts on the head and spreads down to the rest of the body. Other symptoms may include:

  • Cough, runny nose, and red, watery eyes

  • Small spots in the cheek area inside the mouth, called Koplik spots

  • Diarrhea

  • Ear infection

Measles can also lead to serious complications, such as pneumonia, infection of the brain, deafness, intellectual disability and even death.

How long does it take to get measles after being exposed to it?

Measles symptoms typically begin about 8 to 12 days after your child was exposed to the virus. If your child was exposed to someone with measles, call your pediatrician right away. They can check your child's health records. If needed, your pediatrician can arrange to have your child examined without putting others at risk.

How long should a child with measles stay home from school?

Children who have measles should stay home from school or child care until 4 days after the rash starts when they are no longer contagious. Your pediatrician can let you know when it is safe for your child to return to school or child care. This will help avoid spreading measles to others.

How do you prevent the spread of measles?

Measles is a vaccine-preventable infection. About 95 of every 100 people will be protected after getting one dose of the MMR vaccine. Two doses of MMR protect 97-99 of every 100 people.

To avoid the disease, immunize according to recommended schedule—when a child is 12 to 15 months of age and with a second dose at their checkup when they are 4 to 6 years of age. Some children at higher risk may need 3 doses if there is a disease outbreak.

Infants age 6-12 months old can get a measles vaccine during an outbreak or before international travel to a location with an active measles outbreak.


Children who are vaccinated with MMR develop lasting immunity and protect others. When most of us have immunity to measles, it is less likely to spread. If you think that your child has been exposed to measles, call your pediatrician right away.

More information

Last Updated
Adapted from Managing Infectious Diseases in Child Care and Schools: A Quick Reference Guide (American Academy of Pediatrics (Copyright © 2023)
The information contained on this Web site should not be used as a substitute for the medical care and advice of your pediatrician. There may be variations in treatment that your pediatrician may recommend based on individual facts and circumstances.
Follow Us