KING COUNTY, Wash. — The first case of measles in Washington state this year has been identified in a King County infant. 

Public Health – Seattle & King County was notified of the confirmed case Wednesday and said the infant was possibly infected during recent travel abroad. Officials released a list of dates and locations where the infant was in the last few days. Anyone who was there in that timeframe could have been exposed to measles.

• Feb. 20 from 6-9 p.m.: Apple Store at Bellevue Square
• Feb. 21-22 from 10:30 p.m. to 2:15 a.m.: Seattle Children's Hospital Emergency Department at Sand Point Way NE
• Feb. 24 from 1-4:15 p.m. Allegro Pediatrics in Bothell
• Feb. 25 from 1-4 p.m.: Northwest Asthma & Allergy Center
• Feb. 25 from 2:30-5:30 p.m.: Seattle Children's Hospital Emergency Department at Sand Point Way NE

Anyone who was at the locations at the times listed above and is not immune to measles will most likely become sick between Feb. 27 – and March 18. 

The infant was likely not fully vaccinated because the first dose of the rubella (MMR) vaccine is typically administered between the ages of 12 to 15 months and children are eligible for the second dose at 4 years old. Infants and young children are at risk for severe disease from measles.

Two doses of the measles, mumps and MMR vaccine provides about 97% protection against getting infected by measles and that protection lasts a lifetime, according to health officials.

This comes days after an unvaccinated child in Texas died from measles. It was the first measles death in the country since 2015. Measles has now been reported in at least 10 states. 

How does this compare to last year?

In 2024, King County saw three confirmed measles cases. 

According to health officials, due to the current vaccination rate in the county it is likely there will be more frequent and larger breakouts of the highly infectious disease. Herd immunity, which helps prevent rapid spread of diseases among a large population, requires about 95% of people to be vaccinated against measles. According to King County records, 87% of 2-year-olds in the county are up to date on the MMR vaccine, and an estimated 72% of 4 to 6-year-olds have received a total of two doses of the vaccine. 

Washington state as a whole is seeing a decline in childhood vaccination rates as well. 

Data from the Washington state Department of Health's (DOH) school immunization data dashboard shows the percentage of enrolled K-12 students receiving complete immunization decreased from about 92.6 percent in school years from 2020 to 2021, down to 90.8 percent in the 2023-2024 school year.

Among kindergartners, the decline was slightly sharper, with 90% receiving complete immunization in the 2019-2020 school year down to 87% in 2023-2024.

Measles symptoms

Measles spreads through the air and is highly contagious, according to the Center for Disease Control. Measles has a characteristic rash; it is red and flat, and it first appears on the face. 

According to the CDC, other initial symptoms include fever, cough, runny nose and watery eyes. Tiny white spots may appear inside the mouth two to three days after those symptoms begin and before the distinct rash forms. The rash usually begins as flat red spots that appear on the face at the hairline. They then spread downward to the neck, trunk, arms, legs, and feet.

Groups who are most likely to experience severe symptoms include children under age 5, pregnant people and people with weakened immune systems or underlying chronic conditions, according to the CDC.