Measles Outbreak Associated with Vaccine Failure in Adults--Federated States of Micronesia February-August 2014.

Thursday, 28th of April 2016

MMWR Morb Mortal Wkly Rep. 2015 Oct 2;64(38):1088-92. doi: 10.15585/mmwr.mm6438a7.

Measles Outbreak Associated with Vaccine Failure in Adults--Federated States of Micronesia February-August 2014.

Breakwell L Moturi E Helgenberger L Gopalani SV Hales C Lam E Sharapov U Larzelere M Johnson EMasao C Setik E Barrow L Dolan S Chen TH Patel M Rota P Hickman C Bellini W Seward J Wallace G Papania M.

Abstract

On May 15 2014 CDC was notified of two laboratory-confirmed measles cases in the Federated States of Micronesia (FSM) after 20 years with no reported measles. FSM was assisted by the World Health Organization (WHO) the United Nations Childrens Fund (UNICEF) and CDC in investigating suspected cases identify contacts conduct analyses to guide outbreak vaccination response and review vaccine cold chain practices. During February–August three of FSMs four states reported measles cases: Kosrae (139 cases) Pohnpei (251) and Chuuk (3). Two thirds of cases occurred among adults aged ≥20 years; of these 49% had received ≥2 doses of measles-containing vaccine (MCV). Apart from infants aged <12 months who were too young for routine vaccination measles incidence was lower among children than adults. A review of current cold chain practices in Kosrae revealed minor weaknesses; however an absence of historical cold chain maintenance records precluded an evaluation of earlier problems. Each state implemented vaccination campaigns targeting children as young as age 6 months through adults up to age 57 years. The preponderance of cases in this outbreak associated with vaccine failure in adults highlights the need for both thorough case investigation and epidemiologic analysis to guide outbreak response vaccination. Routine childhood vaccination coverage achieved in recent years limited the transmission of measles among children. Even in areas where transmission has not occurred for years maintaining high 2-dose MCV coverage through routine and supplemental immunization is needed to prevent outbreaks resulting from increased measles susceptibility in the population.