Measles outbreaks: who are at risk and why

Abstract

After the introduction of measles vaccine in the United States in 1963 the reported incidence of measles (rubeola) decreased substantially. The disease, however, has not been eliminated. Since 1983, when the lowest number of cases was reported, slight increases in incidence have been observed. Outbreaks are occurring among previously immunized school- and college-age children and unimmunized preschool children and infants. This article describes measles occurrence, transmission, diagnosis, development of measles immunity, the 1989 Centers for Disease Control recommendations for immunization, and implications for health care providers for preventing measles outbreaks.