TRENDS IN IMPORTATION OF MEASLES TO THE UNITED-STATES, 1986-1994

Objectives.-To describe patterns among imported measles cases to the U nited States. Design.-Descriptive analysis of national case-based surv eillance data on measles cases. Setting.-United States in the period 1 986 through 1994. Patients.-All reported confirmed cases of measles. M ain Outcome Measures.-Demographic variables, immunization history, cou ntry of exposure, and reporting state. Results.-The number of reported imported cases of measles to the United States has dropped from an av erage of 99 cases annually in 1986 through 1988 and 190 cases in 1989 through 1991 to 61 cases in 1992 through 1994. Since 1990, the number of imported cases originating in Latin America declined by 98%, despit e continued increase in the number of travelers to this region; cases from other regions remained relatively constant. This decrease paralle led the rapid decrease in measles incidence in the Western Hemisphere associated with national measles elimination programs. Most imported c ases occurred among children, although 22% of cases occurred among you ng adults. Rates of measles cases per 1 million travelers are higher a mong non-US citizens than among US citizens. Conclusions.-The sharp de cline in importations into the United States from Latin America since 1991 provides evidence of the success of measles control efforts under taken there. The decrease in imported cases has been associated with a decline in total measles cases in the United States. Sustained elimin ation of measles in the United States will require improved measles co ntrol in other countries in addition to a high level of population imm unity.