 These were limited to five countries—Nigeria, Pakistan, Afghanistan, Chad, and Niger—of which all except Nigeria had fewer cases than in 2011.Several additional countries, Chad, Democratic Republic of the Congo, Somalia and Yemen, saw outbreaks of circulating vaccine-derived polio.The last reported type3 case of polio worldwide had its onset 11 November 2012 in Nigeria; the last wild case outside Nigeria was in April 2012 in Pakistan, and its absence from sewage monitoring in Pakistan suggests that active transmission of this strain has ceased there.