"Endgame" issues for the global polio eradication initiative.

The polio eradication initiative, created after the World Health Assembly resolved, in 1988, to eradicate poliomyelitis globally by 2000, has made remarkable progress. From 1988 through 2000, the number of countries where polio was endemic decreased from >125 to 20, and the estimated number of polio cases decreased from 350,000 to <3500, for a percentage decrease of >99%. Wild-type 2 poliovirus has not been detected worldwide since October 1999, despite improving surveillance. The major focus of the eradication effort is to complete the task of stopping wild-type poliovirus transmission. Given the rapid progress made toward this goal, planning for the posteradication era has begun in earnest (1) to minimize the risk of reintroduction of virus into the population from laboratory stocks or long-term carriers, and (2) to prevent vaccine-derived polioviruses from circulating and causing outbreaks. This report summarizes the current thinking about these "endgame" issues, as put forth by the World Health Organization's technical advisory body for the initiative, the Technical Consultative Group on the Global Eradication of Poliomyelitis.