Measles in the U.S.: 2011 Was a Bad Year

Measles elimination (i.e., interruption of year-round endemic transmission) was achieved in the U.S. in 2000. From 2000 through 2010, measles occurred infrequently (median, 60 cases and 4 outbreaks annually) and was usually associated with importations. During 2011, 222 cases and 17 outbreaks were reported from 31 states.

Investigation by the CDC revealed that 200 (90%) of the cases in 2011 were associated with importations. Most cases of measles importation were linked to U.S. residents returning from travel, often to European countries where measles is still endemic (e.g., France, U.K., Italy). Seventeen outbreaks (defined as ≥3 related cases) accounted for 50% of the cases. Median patient age was 14 years (range, 3 months to 84 years; 39%…