National laboratory inventory as part of global poliovirus containment--United States, June 2002.

Since the initiation of the global poliomyelitis initiative in 1988 through 2001, the number of countries where polio is endemic decreased from 125 to 10, and the number of reported polio cases decreased >99%, from an estimated 350,000 to <1,000. The Global Commission for the Certification of the Eradication of Poliomyelitis, convened by the World Health Organization, will declare the world polio-free when all regions have documented the absence of wild poliovirus transmission for at least 3 consecutive years and when laboratories with wild poliovirus materials have implemented appropriate containment conditions.