Measles

Measles is highly contagious and can be spread to others from four days before to four days after the rash appears. Measles is so contagious that if one person has it, 90% of the people close to that person who are not immune will also become infected with the measles virus.

Measles is spread through the air by an infected person breathing, coughing or sneezing. The virus resides in the infected person’s nose and throat mucus. When that person sneezes or coughs, droplets spray into the air and land on surfaces. The virus remains contagious on an infected surface and in the air for up to two hours. Other people become infected when they breathe in infected droplets or put their fingers in their mouth or nose after touching an infected surface.

Measles is a disease of humans; measles virus is not spread by any other animal species.

While measles is almost gone from the United States, it still kills nearly 200,000 people each year around the world.

About 30% of measles cases develop one or more complications, including:

• Pneumonia, which is the complication that is most often the cause of death in young children.
• Ear infections occur in about 1 in 10 children infected with measles and permanent loss of hearing can result.
• Diarrhea is reported in about 8% of cases.
• About 1 in 5 unvaccinated people in the U.S. who get measles are hospitalized.
• About 1 child out of every 1,000 who get measles will develop encephalitis (swelling of the brain) that can lead to convulsions and can leave the child deaf or with intellectual disability.
• Nearly 1 to 3 of every 1,000 children who become infected with measles will die from respiratory and neurologic complications.
• Measles may cause pregnant women who have not had the MMR vaccine to give birth prematurely, or have a low-birth-weight baby.

These complications are more common among children under 5 years of age and adults over 20 years old.

Long-term complications

Subacute sclerosing panencephalitis (SSPE) is a very rare, but fatal disease of the central nervous system that results from a measles virus infection acquired earlier in life.

• SSPE generally develops 7 to 10 years after a person has measles, even though the person seems to have fully recovered from the illness.
• Since measles was eliminated in 2000, SSPE is rarely reported in the United States.
• Among people who contracted measles during the resurgence in the United States in 1989 to 1991, 7 to 11 out of every 100,000 were estimated to be at risk for developing SSPE.
• The risk of developing SSPE may be higher for a person who gets measles before they are 2 years of age.
• To learn more, visit the Subacute sclerosing panencephalitis (SSPE) MedlinePlus Medical Encyclopedia.

For enhanced surveillance, please read the SURV alert from 9/1/2022.

• Disease Reporting in Maricopa County
• Measles Screening Tool (PDF)
• Measles Description Flyer (PDF)
• CDC Info for Health Professionals - Vaccine Recommendations, Clinical info, References and Resources