Progress toward polio eradication - worldwide, 2014-2015.

In 1988, the World Health Assembly of the World Health Organization (WHO) resolved to eradicate polio worldwide. Wild poliovirus (WPV) transmission has been interrupted in all but three countries (Afghanistan, Nigeria, and Pakistan). No WPV type 2 cases have been detected worldwide since 1999, and the last WPV type 3 case was detected in Nigeria in November 2012; since 2012, only WPV type 1 has been detected. Circulating vaccine-derived poliovirus (cVDPV), usually type 2, continues to cause cases of paralytic polio in communities with low population immunity. In 2012, the World Health Assembly declared global polio eradication "a programmatic emergency for global public health", and in 2014, WHO declared the international spread of WPV to previously polio-free countries to be "a public health emergency of international concern". This report summarizes global progress toward polio eradication during 2014-2015 and updates previous reports. In 2014, a total of 359 WPV cases were reported in nine countries worldwide. Although reported WPV cases increased in Pakistan and Afghanistan, cases in Nigeria decreased substantially in 2014, and encouraging progress toward global WPV transmission interruption has occurred. Overcoming ongoing challenges to interruption of WPV transmission globally will require sustained programmatic enhancements, including improving the quality of supplementary immunization activities (SIAs) to interrupt transmission in Afghanistan and Pakistan and to prevent WPV exportation to polio-free countries.