Progress toward interruption of wild poliovirus transmission--worldwide, 2008.
Since 1988, when the Global Polio Eradication Initiative was established, the incidence of polio has decreased from an estimated 350,000 cases annually to 1,655 reported in 2008. Cases of wild poliovirus (WPV) type 2 were last reported in October 1999, and indigenous WPV types 1 and 3 (WPV1 and WPV3) have been eliminated from all but four countries worldwide (Afghanistan, India, Nigeria, and Pakistan). This report updates previous reports and describes overall progress toward global eradication in 2008. Despite accelerated efforts, polio cases increased 26%, from 1,315 cases in 2007 to 1,655 in 2008. This increase primarily resulted from an increase in Nigeria from 285 cases in 2007 to 801 cases in 2008. Resurgent WPV1 transmission in northern states of Nigeria spread to polio-free southern states and eight neighboring countries in 2008. In India, repeated use of monovalent oral poliovirus vaccine (OPV) type 1 (mOPV1) during 2005--2008 interrupted WPV1 transmission in the western districts of the northern state of Uttar Pradesh for >12 months during 2007--2008; however, in mid-2008, WPV1 imported from the neighboring state of Bihar caused renewed transmission. In Afghanistan and Pakistan, problems in accessing children in conflict-affected areas increased, and an upsurge in WPV1 and WPV3 cases occurred, including an outbreak of WPV1 in Punjab Province, Pakistan. In Africa, during 2008, sustained WPV transmission for >12 months after importation continued in Angola, Chad, the Democratic Republic of the Congo (DRC), Niger, and southern Sudan. Increased political oversight and accountability and improved vaccination outreach to insecure areas are needed to achieve the eradication goal.