Table 2. Polio Outbreaks in the 16 Countries .

Country	Reported Wild Polio Virus and Circulating Vaccine Derived Polio Virus
Afghanistan	Polio cases in 2016 were concentrated in the southern regions and along the border with Pakistan. Four cases were reported in 2016 from Bermel District bordering Pakistan, which is controlled by antigovernment forces.26 The total number of WPV1 cases reported in Afghanistan in 2018 is 12 (reported as of September 2018).26
CAR	Although no indigenous cases have been reported since 2000, imported cases were reported from Southern Chad and DRC.27
Chad	An outbreak was reported in 2010 from a newly imported case from Northern Nigeria, with absent/destroyed health infrastructure across Chad facilitating further spread.28 Chad experienced outbreaks of both wild poliovirus type 1 (WPV1 – 65 cases in 2011) and wild poliovirus type 3 (WPV3 – 3 cases) in 2011.29
Cote D’Ivoire	17 cases of polio re-emerged in the north of the country following the crisis in the north.30 Since 2002 the country has been divided between the rebel-held north and the government-controlled south, with many healthcare workers fleeing from the north.31 In 2011 Côte d'Ivoire experienced an outbreak of WPV3 with 3 new cases reported with onset of paralysis in 2011.32
DRC	In 2010, an estimated 2.6 million people lived away from home in DRC. There were 100 polio cases in 2010, and in 93 cases in 2011. Efforts to prevent polio have been complicated by conflict and insecurity including displacement of 2.5 million people.33 Two separate cVDPV2s have been confirmed in 2017.34
Ethiopia	Highest risk areas for polio transmission were from the Somali region of Ethiopia, where the last cases occurred in 2013.35 There were 10 confirmed WPV cases in 2013. The affected area is characterised by insecurity, weak infrastructure and communication.36 The country is currently (2018) conducting a polio campaign to focus on pastoralist, refugees, IDPs, hard to reach and border areas and cross-border surveillance with Somalia.37
Kenya	A 4-month-old girl from near Dadaab (refugee camp with estimated population of 500 000) developed ADP in 2013. Two contacts tested positive for WPV1. Risk is considered high in this region, due to large scale population movements across the Horn of Africa.38
Myanmar	Two cases of cVDPV were detected in Rakhine State in 2017, the location of recent communal conflicts, and where in some of the Townships only 27% of children received 3 doses of polio vaccine.39
Pakistan	54 polio cases reported in 2015, with cases concentrated in conflict affected border regions.40 In 2016, cVDPV2 was detected from environmental samples in Quetta, Balochistan. 19 WPV cases were also detected in the same year. The area affected is part of a cross border common reservoir for WPV1 that extends into Southern Afghanistan.41
Nigeria	Two polio cases were detected in Northern province of Borno, demonstrating the need to prioritise services in the Lake Chad Region (often affected by conflict and large population movements).42 The Government reported 3 laboratory-confirmed WPV1 cases in 2016 from Borno State.43
Somalia	During a polio outbreak in 2007, there were 228 cases, mostly from IDP.44 Circulation of cVDPV2 has been confirmed in Somalia in 2018.45
South Sudan	2 cases of cVDPV were confirmed from IDPs in Unity State (conflict-affected region of the South) in 2014.46
Sudan	The last reported polio cases were in 2009, and the country has been polio free since then. High risk areas remain in border areas with Chad in Darfur State.47 The earlier outbreaks were initially restricted to southern Sudan and western Ethiopia, after which cases spread to northern Sudan (in Khartoum and Port Sudan).48
Uganda	A polio case detected in the Bugiri district in mid-October 2010.49
Ukraine	Low coverage is amplified by ongoing conflict and displacement in the east. Two cases of circulating vaccine-derived poliovirus type 1 have been confirmed in 2015,50 along with 3667 cases of rubella, 2937 cases of pertussis, and 995 cases of mumps.4
Yemen	There are an estimated 14.8 million that have no access to health services, with WHO launching large scale campaigns to prevent polio and measles.51

Abbreviations: WPV1, wild polio virus type 1; DRC, the Democratic Republic of Congo; cVDPV2s, circulating vaccine-derived poliovirus type 2s; IDP, internally displaced person; ADP, acute flaccid paralysis; WHO, World Health Organization; WPV, wild polio virus; WPV 3, wild polio virus type 3; cVDPV, circulating vaccine-derived poliovirus.