5 things to know about measles
Measles, a highly contagious disease, has been making headlines in the United States due to the recent increase in reported cases across several states.
To learn more, we talked to Melanie Wellington, MD, PhD, associate hospital epidemiologist, in this Epi Explains.
At a glance
- Symptoms may begin like the flu, but a spotty rash will soon follow.
- Children younger than 5 years old, and people who are pregnant or who have a weakened immune system, are more at risk of serious complications from measles.
- Measles spreads through infected air droplets produced after someone infected with the virus coughs or sneezes.
- The best protection against measles is measles, mumps, and rubella (MMR) vaccine. The MMR vaccine provides long-lasting protection against all strains of measles.
1. What are the symptoms?
Symptoms typically begin to appear 10 to 14 days after measles exposure.
Typical first symptoms
Two to three days after symptoms begin: Koplik spots
Tiny white spots (known as Koplik spots) may appear inside the mouth two to three days after symptoms begin. Not everyone develops these spots.
Three to five days after symptoms begin: measles rash
Measles rash usually begins as flat red spots that appear on the face around the hairline. These spots will spread downward to the neck, trunk, arms, legs, and feet. The spots may begin to cluster together as they spread across the body, and the patient’s fever may spike to more than 104 degrees Fahrenheit when these rashes appear.
Complications from the disease can include pneumonia, inflammation of the brain (encephalitis), blindness, and death. Overall, 10% to 20% of patients and up to 40% of children under 5 who get measles have to be hospitalized.
2. Who is at risk?
If you have not received the MMR vaccine (measles, mumps, and rubella), there is more than a 90% chance you will become sick if you are exposed to the virus.
Measles can be serious in all age groups, but it is especially dangerous for babies and children less than five years old.
Other groups that are more likely to experience measles complications:
- Those who are pregnant
- Those with weakened immune systems, such as from leukemia or HIV infection
3. How does it spread?
Like other airborne viruses, measles spreads through inhalation of infected air droplets that are produced after a person with measles coughs or sneezes. If someone breathes the contaminated air or touches an infected surface then touches their eyes, nose, or mouth, they can become infected.
The virus can remain suspended for up to two hours in the air after an infected person leaves an area. An infected person can spread measles to others before the infected person even has any symptoms. Measles can be spread from four days before through four days after rashes appear.
Note: Measles is only spread from person to person. Other animals cannot be infected with measles, nor can they spread the virus.
4. How can I protect myself and others?
The best way to protect against measles is through the measles, mumps, and rubella (MMR) vaccine or the MMRV vaccine which protects against chickenpox too. If you are not vaccinated, it is very likely you will become sick if you are exposed to the virus.
Most people who are vaccinated with the MMR or MMRV vaccine will be protected for life and do not require a booster.
Except in special circumstances—such as travel or local outbreaks—children under 12 months old are too young to immunize for measles. The best way to protect babies and others who cannot be vaccinated—including those who are pregnant, have allergies to vaccine ingredients, or some who are immunocompromised—is to make sure that everyone around them is fully immunized. Ask friends who are sick or who may have been exposed to stay at home.
If you are traveling internationally or to an area with an active outbreak with a 6 to 12-month-old, that child may be a candidate for an extra “early” dose of MMR. Talk to your child’s health care provider to learn more.
It is important for a person with measles to isolate at home away from vulnerable family members and the community to reduce the risk of spreading it to others.
It is recommended that children receive two doses of the MMR or MMRV vaccine: one at 12-15 months old and the second at four to six years old.
5. For community health care providers:
If you suspect you've encountered a patient with measles, contact your county health department with any questions or concerns.
The takeaway?
Measles is a severe, highly contagious disease that is causing infections in different areas throughout the United States. The good news is that a safe and effective vaccine is available that provides long-term protection against the virus.