Progress toward poliomyelitis eradication--Nigeria, January 2008-July 2009.

Although wild poliovirus (WPV) cases in Nigeria decreased from 1,129 in 2006 to 285 in 2007, Nigeria had the world's highest polio burden in 2008, with 798 (48%) of 1,651 WPV cases reported globally, including 721 (74%) of 976 WPV type 1 (WPV1) cases. This report provides an update on progress toward polio eradication in Nigeria during 2008-2009 and activities planned to interrupt transmission. During 2008-2009, Nigeria was the source for WPV1 transmission to 11 countries and WPV type 3 (WPV3) transmission to four countries. In addition, transmission of circulating type 2 vaccine-derived poliovirus (cVDPV2) has been ongoing since 2005. WPV1 cases decreased 87%, from 574 during January-July 2008 to 73 for the same period in 2009. However, WPV3 cases rose approximately six-fold, from 51 during January-July 2008 to 303 during the same period in 2009, partly because of the increased emphasis on controlling WPV1. The decline in the proportion of children who have never received oral poliovirus vaccine (OPV) in the highest- incidence northern states, from 31% in 2006 to 11% in the first half of 2009 indicates progress toward eradication. During 2008-2009, activities to accelerate polio eradication included use of mobile teams to vaccinate children not at home during supplemental immunization activities (SIAs), and efforts to increase political oversight and the engagement of community leaders. Sustained support of traditional, religious, and political leaders and improved implementation of SIAs will be needed to interrupt WPV and cVDPV2 transmission.