No measles cases reported at Mary Wayte Pool after potential exposure

Published 11:30 am Wednesday, July 9, 2025

Approximately three weeks after an individual visited Mercer Island’s Mary Wayte Pool prior to being diagnosed with measles, facility general manager Keith Freeman relayed an update on the situation.

“There have not been any reported new cases that may have been caused from the potential exposure that happened in June. Our patrons have not expressed concern over it and our staff reported that they were vaccinated,” he said.

Public Health — Seattle & King County Communications Specialist Sharon Bogan delved into the scenario: “If someone was exposed at the Mary Wayte Pool and was not immune to measles, the most likely time they would become sick would be between June 25, 2025-July 9, 2025. We are not currently aware of additional cases that resulted from exposures at the public locations.”

On June 25, Public Health sent the pool a letter that informed staff of the individual’s presence at the Island facility between 1 p.m. and 4 p.m. on June 18, according to a previous Reporter story.

At that time, Public Health said it learned of two new measles cases in King County residents from the same household, and that one of the individuals — either a child or an adult family member — was inside the Island facility. One or both of the individuals also spent time at other Eastside locations between June 14-20 before their diagnoses were confirmed.

As suggested in the letter, Freeman said the pool’s staff notified people who were known to be present at the pool during the time of the potential exposure.

“The notice informed people about the risk, to assess their vaccination status and contact a healthcare provider immediately if they develop symptoms, such as fever or rash,” Bogan said. “Most people in King County are vaccinated against measles, so the risk to the general public is low. However, it’s crucial to take precautions to prevent potential spread, especially if you are not immune.”