RESUMO
A large measles outbreak occurred in Sri Lanka from October 1999 through June 2000 following a period of low incidence. During this period, >15,000 suspected cases were reported to the central Epidemiological Unit of the Department of Health Services. The outbreak was investigated through review of surveillance data for 1999-2000, which were compared with previous surveillance data. Among the clinically confirmed cases, the highest morbidity rate (114/100,000 population) was observed among children <9 months of age. Nearly 54% of the cases were among persons >/=15 years old, and this percentage had increased over the previous decade. Forty percent of cases had a history of measles vaccination. There were 5 deaths, giving a case-fatality rate of 0.1%. Action taken during the outbreak and plans for future outbreak prevention strategies were also evaluated.