Measles is a highly contagious viral disease that can lead to severe and sometimes life-threatening complications. The good news is that measles can be prevented through vaccination.
While measles was once under control in the United States, recent outbreaks have occurred in areas where vaccination rates have dropped. (For more information, see "School Attendance During a Measles Outbreak" and "Measles Vaccine Requirements for International Travel.")
Given how easily measles spreads, outbreaks can occur rapidly. Typically, children who contract measles either haven't received the recommended vaccines or are too young to be vaccinated.
The U.S. immunization program for children and adolescents has reduced measles cases by over 99% since 1963. However, international travelers can bring measles back to the U.S., spreading it to vulnerable individuals and potentially triggering outbreaks.
Once a case of measles is identified in a community, it’s treated as an outbreak due to the disease’s rapid spread. Local health officials must act quickly to identify and isolate those exposed to prevent further transmission.
Travel Tips for Families with Young Children
Infants under 6 months: These babies are too young to be vaccinated but may receive some protection from maternal antibodies. Consider postponing travel to areas experiencing measles outbreaks.
Infants 6-11 months: Should receive their first dose of the MMR vaccine at least two weeks before traveling. They will still need the standard 2-dose series later.
Children 12 months and older: Should receive the first dose of the MMR vaccine, followed by the second dose 28 days later, along with other age-appropriate vaccines.
Before Traveling: Check the Centers for Disease Control and Prevention (CDC) Travel Health Notices for advisories. Additional vaccines may be recommended depending on your destination.
How Contagious is Measles?
Measles is one of the most contagious diseases in the world. If unvaccinated or not immune, 9 out of 10 people exposed to measles will contract it. Even brief exposure to someone with measles in a shared space can result in infection.
When is a Person with Measles Contagious?
Individuals with measles are contagious before they realize they are sick—4 days before the rash appears and up to 4 days afterward.
How Does Measles Spread?
Measles spreads through direct person-to-person contact and via airborne droplets from coughs or sneezes. The virus can survive on surfaces and in the air for up to two hours, making it possible for someone to contract measles simply by entering a room where an infected person had been.
What are the Symptoms of Measles?
Measles symptoms typically start with a high fever, followed by a rash that begins on the head and spreads downward. Additional symptoms may include:
Cough, runny nose, and red, watery eyes
Small white spots inside the mouth (Koplik spots)
Diarrhea
Ear infections
Measles can also lead to severe complications such as pneumonia, encephalitis (brain swelling), deafness, intellectual disabilities, and even death.
What to Do if Your Child is Exposed to Measles
Symptoms usually appear 8-12 days after exposure. If you suspect your child has been exposed, contact your pediatrician immediately. They can review your child's immunization records and arrange for a safe examination if needed.
When Should a Child with Measles Stay Home?
Children with measles should remain home from school or daycare until at least 4 days after the rash appears, once they are no longer contagious.
School Attendance During a Measles Outbreak
During a measles outbreak:
Children who haven’t been vaccinated should stay home.
Unvaccinated children who have no known exposure can return to school after receiving the MMR vaccine.
Children exposed to measles who receive the vaccine within 72 hours of exposure can return to school immediately.
Those vaccinated more than 72 hours after exposure should stay home for 21 days from the last known exposure.
Unvaccinated children who do not receive the vaccine should stay home for 21 days after the last case of measles is reported.
Your pediatrician will advise when it is safe for your child to return to school, helping to protect others who may be unable to receive the vaccine.
Preventing Measles
Measles is preventable through vaccination. One dose of the MMR vaccine protects about 95 out of every 100 people, while two doses increase protection to 97-99%. Follow the recommended vaccination schedule, starting with the first dose at 12-15 months of age and a second dose at 4-6 years. In certain situations, such as during an outbreak, a third dose may be needed.
Remember
Vaccinating your child with the MMR vaccine not only protects them but also helps prevent the spread of measles to others. If you suspect your child has been exposed to measles, contact your pediatrician right away.