Overview
- State and federal laboratories confirmed the H5N5 subtype, with identification by the UW Medicine Clinical Virology Lab and confirmation by the CDC.
- The deceased was an older adult with underlying health conditions from Grays Harbor County who had been hospitalized in King County since early November.
- Investigators detected avian influenza in the environment of the household’s mixed backyard flock, pointing to exposure from domestic poultry or visiting wild birds.
- No additional human infections have been identified, there is no evidence of person-to-person spread, and health officials continue to monitor close contacts and those linked to the flock.
- The case occurs during ongoing U.S. bird flu surveillance with roughly 70 recent human infections mostly tied to H5N1, and it marks the second U.S. bird flu death reported in 2025.