Health Care–Associated Measles Outbreak in the United States After an Importation: Challenges and Economic Impact

Abstract

(See the editorial commentary by Ostroff, on pages 1507–9.)

Background. On 12 February 2008, an infected Swiss traveler visited hospital A in Tucson, Arizona, and initiated a predominantly health care–associated measles outbreak involving 14 cases. We investigated risk factors that might have contributed to health care–associated transmission and assessed outbreak-associated hospital costs.

Methods. Epidemiologic data were obtained by case interviews and review of medical records. Health care personnel (HCP) immunization records were reviewed to identify non–measles-immune HCP. Outbreak-associated costs were estimated from 2 hospitals.

Results. Of 14 patients with confirmed cases, 7 (50%) were aged ≥18 years, 4 (29%) were hospitalized, 7 (50%) acquired measles in health care settings, and all (100%) were unvaccinated or had unknown vaccination status. Of the 11 patients (79%) who had accessed health care services while infectious, 1 (9%) was masked and isolated promptly after rash onset. HCP measles immunity data from 2 hospitals confirmed that 1776 (25%) of 7195 HCP lacked evidence of measles immunity. Among these HCPs, 139 (9%) of 1583 tested seronegative for measles immunoglobulin G, including 1 person who acquired measles. The 2 hospitals spent US$799,136 responding to and containing 7 cases in these facilities.

Conclusions. Suspecting measles as a diagnosis, instituting immediate airborne isolation, and ensuring rapidly retrievable measles immunity records for HCPs are paramount in preventing health care–associated spread and in minimizing hospital outbreak–response costs.