Review of regional measles surveillance data in the Americas, 1996-99

Background In 1994, ministers of health of countries of North and South Ame rica established the goal of measles eradication from the western hemispher e by 2000. To accomplish this goal, the Pan American Health Organization (P AHO) developed an enhanced measles vaccination strategy. Methods PAHO's measles eradication vaccination strategy has evolved into th ree principal components; a catch-up measles Vaccination campaign, maintena nce of high vaccination coverage (keep-up), and periodic follow-up measles vaccination campaigns. ro monitor progress towards measles eradication, mea sles surveillance has been strengthened, including the laboratory investiga tion of suspected measles cases. and periodic follow-up To monitor progress Findings Both the catch-up and follow-up mass campaigns achieved high vacci nation coverages in the respective targeted age groups. In 1996, only 2109 confirmed measles cases were reported in the Americas. In 1997, there was a resurgence of measles in the Americas, mostly as a result of a large measl es outbreak with over 42000 cases, which occurred mainly among unvaccinated young adults in Sao Paulo State, Brazil. By 1998, there was a reduction in the number of reported confirmed measles cases, with a total of 14474 case s. Reduction of cases continued to the end of 1999, with a total of only 28 28 confirmed cases. Interpretation PAHO's measles eradication strategy has been effective in in terrupting transmission and maintaining the absence of measles Virus circul ation in most parts of the Americas. The PAHO experience provides strong ev idence that with full implementation of an appropriate Vaccination strategy , measles transmission can be effectively interrupted.