Outbreak of Rotavirus Diarrheal Infection among Adults in King County, Washington, January-June 2023.

Rotavirus is a leading cause of diarrhea among children but less known as a cause among adults. We describe clinical, epidemiologic, and genotype characteristics of a rotavirus outbreak among adults in King County, Washington occurring January-June 2023. Adult rotavirus incidence in 2023 was ten times higher than the same period in 2022 (5% versus 0.