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Confirmed measles case in Snohomish County resident—Potential risk of exposure for unvaccinated people at locations in King County


Local public health officials have confirmed a measles infection in an infant residing in Snohomish County. The person is believed to have been infected with measles during travel in South Asia prior to arriving in the state.


SNOHOMISH COUNTY, Wash. – Local public health officials have confirmed a measles infection in an infant residing in Snohomish County. The person is believed to have been infected with measles during travel in South Asia prior to arriving in the state. The Health District's Communicable Disease & Surveillance team is also monitoring the health status of other individuals in the family who were exposed.

Confirmation came in February 21. Before the infant was diagnosed, others may have been exposed in the following locations:

Sea-Tac Airport during these times:

  • February 19: 11:45 a.m. – 2:45 p.m.

Seattle Children's Hospital, Emergency Room Lobby, 4800 Sand Point Way NE, Seattle, during these times:

  • February 20: 12:34 a.m. – 2:49 a.m.

Health officials at the Snohomish Health District, Public Health – Seattle & King County, and Washington State Department of Health have been contacting impacted locations to alert them of the potential exposures.

Most people in our area have immunity to the measles through vaccination, so the risk to the general public is low. However, anyone who was in the above locations around the same time as the individual with measles should:

  • Find out if they have been vaccinated for measles, have evidence of measles immunity from blood testing, or have had measles previously. Measles vaccination is recommended within 72 hours of exposure for people who are not already immune. AND

  • Call a health care provider promptly if they develop an illness with fever or illness with an unexplained rash between now through March 12. To avoid possibly spreading measles to other patients, do not go to a clinic or hospital without calling first to tell them you want to be evaluated for measles.

To protect the privacy of the infant and family, no additional information about the measles case is being shared at this time.

About measles

Measles is a highly contagious and potentially severe disease that causes fever, rash, cough, and red, watery eyes. It is mainly spread through the air after a person with measles coughs or sneezes.

Measles symptoms begin seven to 21 days after exposure. Measles is contagious from approximately four days before the rash appears through four days after the rash appears. People can spread measles before they have the characteristic measles rash.

People at highest risk from exposure to measles include those who are unvaccinated, pregnant women, infants under six months of age and those with weakened immune systems. A person is considered immune to measles if any of the following apply:

  • You were born before 1957
  • You have had a blood test result that shows immunity to measles
  • You are certain you have previously had measles diagnosed by a healthcare provider
  • You are up-to-date on measles vaccines (one dose for children age 12 months through three years old, two doses in anyone four years and older).

The following table shows the frequency of measles case reports locally:

Year Snohomish County Washington State
 2017 0 3
 2018 6 8
 2019 1 90
 2020 0 1
 2021 0

Sporadic cases and small clusters of cases are usually initiated by importation after travel from another country where measles is more widespread. Larger outbreaks are often seeded in the same way but then flourish if the virus enters a network or community with low vaccination coverage. While 2-dose measles vaccination is safe and one of the most effective and durable vaccines in use, even fully vaccinated individuals can rarely catch measles. In the 2019 outbreak, though, only 4% of cases were in fully vaccinated people.

Our public health objective is to reduce the chances of a second round of cases connected to this case transmitting to a larger network of exposed people and thereby starting an outbreak.

For more information about measles and measles vaccination, please visit

Vaccine information

Parents and guardians can check their child's immunization status or print their Certificate of Immunization Status at, or by contacting their medical provider.

Vaccines are provided at no cost to all kids through age 18. If a health care provider charges a fee to give the shot, parents or guardians may ask to have it waived if they cannot afford it. By law, no child can be turned away from getting a recommended vaccine from their regular health care provider because the family cannot pay.

Get help finding a health care provider by calling the Family Health Hotline at 1-800-322-2588 or visiting