Number of US measles cases in 2008 highest since 1996, CDC reports

Measles cases occurring in 2008 through July 31 were the highest reported year-to-date since 1996, according to the Centers for Disease Control and Prevention (CDC)'s August 22 Morbidity and Mortality Weekly Report.

The number of measles cases from January 1 to July 31, 2008, was 131, the CDC reported, compared to an average of 63 cases annually from 2000 to 2007.

The authors of the report stated that this increase was not due to an increase of cases of measles imported into the US, but rather due to increased viral transmission after importation. The importation-associated cases mostly centered around school-aged children eligible for vaccination, but whose parents chose not to have them vaccinated.

Of the 131 cases, 89% were imported from or associated with importation from other countries (13% importations, 76% linked to importations); 76% of cases occurred in persons younger than 20; and 91% of cases were either unvaccinated or of unknown vaccinated status. Of this subgroup, 85% were eligible for vaccination, and 66% were unvaccinated due to philisophic or religious beliefs.

The 131 measles cases reported to the CDC occurred in 15 states and the District of Columbia. A total of 81% of the cases resulted from seven measles outbreaks. Among all cases, 11% of patients were hospitalized, which included 4 children younger than 15 months. No deaths were reported.

The investigators emphasized the need to maintain high measles, mumps, and rubella vaccination coverage rates in the US to limit measles spread.

The full report can be accessed on the CDC Web site here.