Measles detected in King County infant

Editor’s note: The following is a press release from the King County Public Health Seattle & King County.

Public Health – Seattle & King County was notified yesterday, February 26, 2025, of a confirmed measles case in a King County infant. The infant may have been exposed to measles during recent travel abroad. Exposed individuals should check to make sure they have been vaccinated against measles.

“Measles is easily spread from person to person. If one person has it, up to 9 out of 10 people nearby will become infected if they are not protected,” said Dr. Eric Chow, Communicable Disease Chief for Public Health – Seattle & King County. “We are seeing increases in measles cases within and outside the US. Talk to your doctor about checking your vaccination status and get vaccinated now if you aren’t already protected.”

Fortunately, the measles vaccine is very effective. Two doses of the measles, mumps and rubella (MMR) vaccine provides about 97% protection against getting infected by measles and that protection lasts a lifetime.

In 2024, there were three cases of measles in King County. Herd immunity, which helps prevent rapid spread of diseases among a large population, requires about 95% of people to be vaccinated against measles because it is so infectious. We are likely to see more frequent and larger outbreaks when vaccination rates are lower than that.

• An estimated 87% of 2-year-olds in King County are up to date on the MMR vaccine (having received one dose of the MMR vaccine).
• An estimated 72% of 4–6-year-olds in King County have received 2 doses of the MMR vaccine.

Infants and children under 5 years old are at risk of severe disease from measles, and receiving one dose of MMR can provide crucial protection from complications. Children are eligible for a second dose of MMR at 4 years old and parents should be encouraged to get the second dose as soon as possible instead of waiting until the child is enrolled in school.

LOCATIONS OF POTENTIAL EXPOSURE

Spread of measles can occur before people know they have the disease, before any rash appears.

The infant was at the following public locations before being diagnosed with measles. These times include the period when the individual was at the location and two hours after. All three medical facilitates listed below are notifying patients and families who may have been exposed, providing information about the exposure date and disease symptoms to watch for.

Measles virus can remain in the air for up to two hours after someone contagious with measles leaves the area. Anyone who was at the following locations during the times listed could have been exposed to measles:

Feb. 20

6 p.m. – 9 p.m.

Apple Store at Bellevue Square

213 Bellevue Square, Bellevue, WA 98004

Feb. 21 – 22

10:30 p.m. – 2:15 a.m.

Seattle Children’s Hospital Emergency Department

4800 Sand Point Way NE, Seattle, WA 98105

Feb. 24

1 p.m. – 4:15 p.m.

Allegro Pediatrics – Bothell

11724 NE 195th St, Ste 100, Bothell, WA 98011

Feb. 25

1 p.m. – 4 p.m.

Northwest Asthma & Allergy Center

8301 161st Ave NE, Ste 308, Redmond, WA 98052

Feb. 25

2:30 p.m. – 5:30 p.m.

Seattle Children’s Hospital Emergency Department

4800 Sand Point Way NE, Seattle, WA 98105

WHAT TO DO IF YOU WERE IN A LOCATION OF POTENTIAL MEASLES EXPOSURE

Most people in our area have immunity to measles through vaccination, so the risk to the general public is low. However, anyone who was in the locations of potential exposure to measles around the times listed should:

• Find out if you have been vaccinated for measles or have had measles previously. Make sure you are up to date with the recommended number of measles (MMR) vaccinations.
• Call a healthcare provider promptly if you develop an illness with fever or with an unexplained rash. To avoid possibly spreading measles to others, do not go to a clinic or hospital without calling first to tell them you want to be checked for measles after an exposure. It is also important to limit contact with others, especially those without known immunity, and to wear a well-fitting mask if you do need to go to a healthcare facility.

If you were at the locations at the times listed above and are not immune to measles, the most likely time you would become sick would be between February 27 – March 18, 2025. People with weakened immune systems may take longer to experience symptoms.

ABOUT MEASLES

Measles is a highly contagious and potentially severe disease that causes fever, rash, cough, runny nose, and red, watery eyes. If one person has it, up to 9 out of 10 people nearby will become infected if they are not protected. It mainly spreads through the air after a person with measles coughs or sneezes.

Measles symptoms begin 7 to 21 days after exposure. Measles is contagious from about 4 days before the rash appears through 4 days after the rash appears. People can spread measles before they have the characteristic measles rash.

Measles can lead to ear infections, diarrhea, pneumonia, and rarely, encephalitis (brain inflammation) or death.

Complications from measles can happen even in healthy people, but those at highest risk include: infants and children under 5 years, adults over 20 years, pregnant people, and people with weakened immune systems from medications or underlying disease.

If you are in one of these high-risk groups and were exposed to measles at one of these locations, be sure to contact your health care provider to discuss any steps you need to take to protect yourself or loved ones against complications from measles.

Measles is preventable with the safe and highly effective measles, mumps and rubella (MMR) vaccine. According to the Centers for Disease Control and Prevention (CDC), two doses of the MMR vaccine are about 97% effective at preventing measles and that protection is long lasting.

For more information about measles and measles vaccination, including where to get measles vaccinations: www.kingcounty.gov/