Progress toward interruption of wild poliovirus transmission--worldwide, January 2004-March 2005.

In 1988, the World Health Assembly of the World Health Organization (WHO) resolved to eradicate poliomyelitis globally. Since then, substantial worldwide progress has been made toward that goal; the number of countries where polio is endemic declined from 125 in 1988 to six by the end of 2003. Further progress in 2004 toward interruption of transmission has continued in the three Asian countries where polio is endemic (Afghanistan, India, and Pakistan). However, in 2003, two countries in Africa experienced a resurgence of polio cases; the resurgence continued to spread in 2004 from the Nigeria-Niger endemic reservoir to involve a total of 14 countries that had not reported polio > or =1 year. Local transmission of wild poliovirus (WPV) has been reestablished in six of these 14 countries, including Sudan, where a major outbreak occurred. This report describes global efforts to eradicate polio during January 2004-March 2005 and outlines remaining challenges to interrupting transmission in countries where polio remains endemic or transmission has been reestablished.