THE GEOGRAPHIC-DISTRIBUTION OF MEASLES IN THE UNITED-STATES, 1980 THROUGH 1989

Objective. - To describe the geographic distribution of measles cases in the United States by county for the 10-year period from 1980 throug h 1989. Design. - Ecological analysis of national measles surveillance data. Methods. - Measles cases reported to the Morbidity and Mortalit y Weekly Report from 1980 through 1989 were analyzed. Data from the 19 80 and 1990 US censuses were used to produce demographic profiles for each of the 3137 counties. Outcome variables examined included mean an nual incidence and number of years reporting measles, with use of Spea rman's rank correlation coefficients to examine the association betwee n the demographic and the two outcome variables. Results. - A total of 56 775 measles cases were reported during the decade. Of the nation's 3137 counties, 1690 (53.9%) did not report any cases; only 17 (0.5%) reported measles in all 10 years. Counties reporting measles more freq uently during the decade had higher median populations, population den sities, and percentage of black and Hispanic populations than those co unties reporting less frequently. Population size, Population density, and percentage of Hispanic population were associated with number of years reporting measles and mean annual measles incidence rate. Measle s cases in counties reporting measles every year predominately occurre d in unvaccinated preschoolers; cases in counties reporting less frequ ently predominately occurred in vaccinated school-aged children. Concl usions. - This analysis illustrates the focal nature of measles in the United States during the past decade. Most counties have not reported a single case of measles during the entire decade, and only 17 counti es reported measles every year. Targeted strategies are needed to impr ove age-appropriate immunization levels among preschool-aged children living in large inner-city areas.