LB-34. Epidemiology of measles in the United States in 2011
Session: Oral Abstract Session: Late Breaker Oral Abstracts
Saturday, October 22, 2011: 6:15 PM
Room: 156ABC
Background: Endemic measles transmission was declared eliminated in the United States in 2000, but importations of measles virus continue to occur. To date in 2011, 178 measles cases were reported, the highest number reported since 1996.

Objective: To describe the measles cases in 2011 to date and compare with those reported since measles elimination was declared (2001-2010).

Method: Confirmed measles cases reported to the Centers for Disease Control and Prevention were reviewed from 2001-2011. Incidence rates were calculated based on US census data.

Result: During January 1-July 8, 2011, measles incidence (0.53/million) was 1.8 times higher than the average incidence during 2001-2010. Among the 161 US residents, 136 (84%) were unvaccinated or had unknown vaccination status, 25 (16%) were aged <12 months, 34 (21%) were aged 1-4 years, 36 (22%) were aged 5-19 years, and 66 (41%) were aged ≥20 years. Age-specific incidence was highest among infants age 6-11 months (9.9/million), followed by those age 12-15 months (4.9/million), and those aged 16 months-4 years (3.8/million). In 2011, there were 58 importations; the most reported during 2001-2011, 42 (72%) were among US residents who traveled abroad. The WHO European region was the source of 27 (47%) importations and genotype D4 was isolated in 16 (28%) importations. Half (51%) of all cases reported in 2011 were associated with 13 outbreaks.

Conclusion: The increased incidence of measles thus far in 2011 is related to increases in measles in countries visited by US travelers. Despite increased importations, measles elimination has been maintained because of high two dose vaccination coverage and rapid control efforts have limited the spread of measles. The measles epidemiology highlights the importance of vaccination, particularly prior to international travel, to prevent measles and its complications.

Subject Category: I. Adult and Pediatric Vaccines

Huong McLean, PHD, MPH, Albert Barskey, BA, MPH, Preeta Kutty, MD, Susan Redd, BA, Jennifer Rota, BS, MPH, Paul Rota, PhD, William Bellini, PhD, Gregory Armstrong, MD and Gregory S. Wallace, MD, MS, MPH, Division of Viral Diseases, Centers for Disease Control and Prevention, Atlanta, GA


H. McLean, None

A. Barskey, None

P. Kutty, None

S. Redd, None

J. Rota, None

P. Rota, None

W. Bellini, None

G. Armstrong, None

G. S. Wallace, None

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.