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Measles (Rubeola)

Page last updated 03/11/2025.

Measles is a virus that infects the respiratory tract and then spreads throughout the body. It is very contagious (spreads easily). If one person has it, up to 9 out of 10 people nearby will become infected if they are not protected. Measles can cause serious health complications, especially in children younger than 5 years old. 

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Prevention

The best way to prevent measles is with the measles, mumps, and rubella (MMR) vaccine.

  • Children may get the measles, mumps, rubella, and varicella (MMRV) vaccine instead, which protects against chickenpox too.
  • Measles infection after exposure to the virus can be prevented with measles vaccination (post-exposure prophylaxis).

The measles vaccine is 2 doses given at least 28 days apart.

  • All children and adolescents ages 12 months and older who have not previously received the vaccine should be vaccinated.
  • Adults who were not vaccinated previously and want to be protected against measles can also get the vaccine.

Where Can I Get The Measles Vaccine?

  • Contact your healthcare provider. If you do not have a healthcare provider, contact 2-1-1.
  • Immunization services are available throughout San Diego at our County Public Health Centers. We recommend calling the site you plan to visit to confirm current hours and immunization availability. 

Transmission (Spread)

Measles is very contagious.

Infographic with stick figures stating “Measles is highly contagious and spreads through the air when an infected person coughs or sneezes. It is so contagious that if one person has it, 9 out of 10 people of all ages around him or her will also become infected if they are not protected.”
  • It is spread through the air when an infected person coughs or sneezes. 
  • If other people breathe the contaminated air or touch the infected surface, then touch their eyes, nose, or mouth, they can get infected. 
  • The virus can live for up to 2 hours in an airspace after the infected person leaves the area.
  • Infected people can spread the virus to others from 4 days before through 4 days after the rash appears.
  • Animals do not get or spread measles.

Symptoms

Measles symptoms appear 7 to 14 days after contact with the virus. Measles typically begins with:

  • High fever (may spike to more than 104˚F),
  • Cough,
  • Runny nose (coryza), and
  • Red, watery eyes (conjunctivitis).
Image of inside of a mouth showing tiny white spots (Koplik spots).

2-3 days after symptoms begin, tiny white spots (called Koplik spots) may appear inside the mouth.

Image of a measles rash shown as flat red spots.

3-5 days after symptoms begin, a rash appears. It begins as flat red spots that appear on the face and spread down towards the neck, trunk, arms, legs, and feet.

  • Small, raised bumps may appear on top of the flat red spots.
  • The spots may become joined together as the rash spreads throughout the body.

Common complications include ear infections and diarrhea. Some people may suffer from severe complications, such as pneumonia (infection of the lungs) and encephalitis (swelling of the brain). They may need to be hospitalized and could die.

Groups at risk of measles complications include:

  • Children younger than 5 years of age
  • Adults older than 20 years of age
  • Pregnant people
  • People with weakened immune systems

Diagnosis and Treatment

If you think you have been exposed to someone with measles, call your doctor as soon as possible and let them know you have been exposed to someone with measles.

  • A doctor can determine if you have measles by discussing your symptoms and ordering a throat, or nasal swab, and a blood test.
  • A doctor can determine if you are immune based on your vaccination record, age, or laboratory evidence, and/or make special arrangements to evaluate you, if needed. 
  • If you do not have a healthcare provider, contact 2-1-1.

There is no cure for measles. Treatment is focused on relieving symptoms. Recommendations are rest, adequate nutrition, and fluids. Some people with severe symptoms will need medical care in a hospital.

Measles and International Travel

Infographic flyer with information about traveling abroad and how to protect against measles.

Plan to be fully vaccinated at least 2 weeks before traveling.

  • Measles cases in the United States originate from unvaccinated international travelers. 
  • People at risk of getting measles are those who have not been fully vaccinated or have not had measles in the past. 

If traveling is less than 2 weeks away, it is still recommended to get a dose of the MMR vaccine. Two doses of MMR vaccine provide 97% protection against measles.

Visit the Centers for Disease Control and Prevention (CDC) Plan for Travel for more information.

Resources

County of San Diego

California Department of Public Health

Centers for Disease Control and Prevention

World Health Organization

Information for Healthcare Professionals

California Health Alert Network San Diego Communications

 

Call the Epidemiology Unit at (619) 692-8499, or send an email, for more information.