What is Measles?

Measles is a highly contagious virus that spreads through respiratory droplets from an infected person. It can remain active and contagious in the air or on surfaces for up to two hours. People can become infected by breathing in contaminated air or touching infected surfaces and then touching their eyes, nose or mouth.

Measles is extremely contagious. If one person has it, up to 90% of unvaccinated individuals close to them may also become infected. The virus can spread from four days before to four days after the appearance of the measles rash.

Severe complications from measles can include pneumonia (infection of the lungs) and encephalitis (inflammation of the brain), which may require hospitalization and, in some cases, lead to death.

• Hospitalization occurs in about one in five unvaccinated people in the United States who get measles.
• Pneumonia occurs in as many as 1 in 20 children with measles and is the leading cause of death from measles in young children.
• Encephalitis affects about 1 in 1,000 children with measles, leading to possible convulsions, deafness or intellectual disability.
• Death occurs in 1 to 3 of every 1,000 children who get measles.
• Complications during pregnancy may occur, including premature birth or having a low-birth-weight baby.

Symptoms of Measles

Measles symptoms typically appear seven to 14 days after exposure but can take up to 21 days to develop. Early symptoms include:

• High fever
• Cough
• Runny nose
• Red, watery eyes (conjunctivitis)

Two to three days after symptoms begin, tiny white spots (Koplik spots) may appear inside the mouth.

Three to five days after symptoms begin, a rash appears. The rash:

• Usually starts as flat red spots at the hairline and spreads downward to the neck, trunk, arms, legs and feet.
• Can include small, raised bumps on top of the flat red spots.
• The spots may merge together as it spreads.
• When the rash appears, fever may spike, sometimes exceeding 104°F.

How is Measles Spread?

The measles virus spreads when an infected person coughs or sneezes, releasing virus-containing droplets into the air. These droplets can land in the nose or throat of people nearby or contaminate surfaces. The virus can live in the air or on surfaces for up to two hours and can be transferred to the nose or mouth by touching infected surfaces.

Infected individuals can spread measles from four days before the rash appears to four days after.

Who is at Risk for Measles?

Measles can be serious for everyone. Groups more at risk of complications from measles include:

• Children younger than five years of age, including infants younger than 12 months, who are too young to receive the vaccine.
• Adults older than 20 years of age.
• People who are pregnant or with weakened immune systems.

How Can Measles Be Prevented?

• Vaccination is the best protection.
• People exposed to measles should check their vaccination status and consult a physician or health department for guidance.
• Isolation of infected individuals from non-immune people is crucial. This includes staying home from school, daycare or work.

If you suspect you or your child has measles, contact your health care provider. Call your doctor’s office or clinic before entering the facility so they can make appropriate arrangements to ensure the illness is not spread.

Is the Measles Vaccine Effective?

The measles vaccine is highly effective and has an excellent safety record. Two doses of the vaccine are 97% effective at preventing measles, and one dose is 93% effective. The MMR vaccine contains a combination of measles, mumps and rubella vaccines.

• Children need two doses of the vaccine. The first dose of the MMR vaccine is given at 12-15 months, and the second dose at 4-6 years.

• Older children, adolescents and adults need one to two doses of MMR vaccine if they don’t have evidence of immunity.

• People traveling internationally should be fully vaccinated. Infants 6-11 months old should get one dose of the MMR vaccine before travel.

Almost everyone who has not had the MMR vaccine will get sick if they are exposed to the virus. During outbreaks, measles vaccination limits the size, duration and spread of the virus.

Where Can I Get More Information?

• Visit the CDC’s Measles webpages.

To make an appoint to get the measles vaccine at a Health District clinic, go to www.SNHD.info/immunizations.