Island County Warns of Measles Exposure on Clinton-Mukilteo Ferry

Island County Public Health cautioned people who were on the Clinton-Mukilteo ferry between 1 and 3 p.m. on Dec. 30 about a possible measles exposure after Snohomish and King county health departments reported three confirmed measles cases during the holiday season. Public health officials said one adult and two children from the same family were infectious from Dec. 27, 2025, to Jan. 1, 2026, while visiting from South Carolina, and the children were not vaccinated.

The primary exposure site identified by the investigation was the Mukilteo-Clinton ferry during the early afternoon on Dec. 30. Island County urged anyone who may have been aboard during that period to verify their immunity status, monitor for symptoms, and take steps to avoid exposing others if illness develops.

Measles typically begins with flu-like symptoms and progresses to a spreading rash. The virus is highly contagious and can lead to serious complications, including pneumonia, brain swelling, deafness and even death, the Centers for Disease Control notes. Because the infectious family traveled through the area during the holiday travel period, public health officials emphasized vigilance among ferry riders, close contacts and people who frequent community settings such as schools and childcare centers.

Island County Public Health advised residents to check their medical records for MMR vaccination history and to stay home if they develop a fever, cough or other symptoms consistent with measles. Anyone seeking medical evaluation is asked to call their health care provider before going to a clinic or emergency room so facilities can take steps to prevent exposure of other patients in waiting areas.

The advisory reinforces a broader regional response after the three confirmed cases were reported in neighboring counties. Local health authorities recommend that people with uncertain immunity or those caring for young children contact their primary care provider or local public health for guidance on testing and vaccination options.

Timely action can reduce further spread. Residents who rode the ferry during the identified window should review their vaccination records now and contact health services if symptoms appear.