Notes from the Field: Community Outbreak of Measles — Clark County, Washington, 2018–2019

Abstract

The objective of the article was to report the epidemiology of measles in Washington from 2018 to 2019. Among the 71 patients with confirmed measles, all of whom met the clinical case definition for measles, 41 cases were laboratory confirmed and 30 were epidemiologically linked to confirmed cases. Sixty-one (86%) were unvaccinated, three (4%) had received 1 dose of measles, mumps, rubella vaccine before measles exposure, and vaccination status was unknown for seven. Genotype D8, which is currently circulating in Eastern Europe, was identified in all 18 specimens tested. Approximately 3,800 named contacts of the 71 patients were identified from 46 known exposures at Clark County health care facilities, workplaces, churches, schools, and child care centers, as well as social gatherings and home settings. Among these contacts, 22% lacked acceptable presumptive evidence of measles immunity.