Public health dispatch: measles epidemic--Majuro Atoll, Republic of the Marshall Islands, July 13-September 13, 2003.

During July 13-September 13, 2003, a total of 647 clinically diagnosed measles cases* were reported on Majuro Atoll in the Republic of the Marshall Islands (RMI); this is the first measles outbreak reported in RMI since 1988. An additional 74 suspected measles cases are under investigation. This report describes the clinically diagnosed measles cases and the public health response to stop the epidemic. Of the 647 cases, 15 (2%) are laboratory confirmed, either by serology, polymerase chain reaction, or viral culture. The age of patients ranged from 2 weeks to 43 years (median: 12 years); 479 (74%) patients were aged <20 years. The overall measles incidence on Majuro Atoll (estimated 2003 population: 25,097) is 26 cases per 1,000 population. The incidence is highest among infants aged <1 year (160 per 1,000 population), followed by children aged 1-4 years (40).