(Photo via iStock/Getty Images Plus)
An infant in King County was identified as the first confirmed measles case in Washington in 2025, following increases in cases in other parts of the United States, county officials said.
There were three cases of measles in King County last year. The new case was confirmed on Wednesday. The infant is suspected to have been exposed to measles during recent travel abroad.
The infant is known to have visited several public locations prior to being diagnosed: the Apple Store at Bellevue Square, Seattle Children’s Hospital Emergency Department, Allegro Pediatrics in Bothell, and Northwest Asthma & Allergy Center in Redmond.
All three medical facilities are notifying patients who may have been exposed and providing information about the exposure date and possible symptoms. Symptoms for those exposed would be likely to appear between Feb. 27 to Mar. 18.
Measles is a highly contagious and potentially severe air-borne disease. Symptoms can include fever, rash, cough, runny nose, and red, watery eyes. It can lead to ear infections, diarrhea, pneumonia, brain inflammation, or death.
“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, a communicable disease chief in King County.
The virus can remain in the air for up to two hours after someone with measles leaves the area. Symptoms can begin seven to 21 days after initial exposure and can spread among people even before someone shows the appearance of a rash.
Even healthy individuals can have complications from the disease, but high risk populations include children under the age of 5, adults over 20, pregnant people, and those who are immunocompromised.
However, high rates of vaccinations have kept the risk to the general public low, though there have been a number of outbreaks in recent years. At least 120 people have been confirmed infected in an ongoing outbreak in west Texas. Officials there reported the first death from the outbreak, a school-aged child who had not been vaccinated, this week.
According to the U.S. Centers for Disease Control and Prevention, two doses of the measles, mumps and rubella vaccine are 97% effective at preventing measles and the protection can last a lifetime.
The best way to prevent measles is by staying up to date with vaccinations, officials say.
Widespread immunity, known as “herd immunity,” prevents the rapid spread of diseases within a large population and requires around 95% of people to be vaccinated against measles. If vaccination rates are lower than that, it increases the risk of larger and more frequent outbreaks.
Parents are encouraged to get their infants their first vaccination around six to 11 months of age and to get their second dose at age 4, instead of waiting until the child is enrolled at school.
In King County, it is estimated that 87% of 2-year-olds are up to date on their first vaccine and 72% ages of 4-to-6-year-olds have received both doses.
Those with a potential exposure should call a clinic and tell them you want to be checked for measles, limit your contact with others, and wear a well-fitting mask if you do need to go to a healthcare facility to avoid the spread of measles, officials say.