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This is a comparative analysis of independent monitoring data collected between 2010 and 2012, following the implementation of supplementary immunization activities (SIAs) in countries in the three sub regional blocs of World Health Organization in the African Region. The sub regional blocs are Central Africa, West Africa, East and Southern Africa. In addition to the support for SIAs, the Central and West African blocs, threatened with importation and re-establishment of polio transmission received intensive coordination through weekly teleconferences. The later, East and Southern African bloc with low polio threats was not engaged in the intensive coordination through teleconferences. The key indicator of the success of SIAs is the proportion of children missed during SIAs. The results showed that generally there was a decrease in the proportion of children missed during SIAs in the region, from 7.94% in 2010 to 5.95% in 2012. However, the decrease was mainly in the Central and West African blocs. The East and Southern African bloc had countries with as much as 25% missed children. In West Africa and Central Africa, where more coordinated SIAs were conducted, there were progressive and consistent drops, from close to 20-10% at the maximum. At the country and local levels, steps were undertaken to ameliorate situation of low immunization uptake. Wherever an area is observed to have low coverage, local investigations were conducted to understand reasons for low coverage, plans to improve coverage are made and implemented in a coordinated manner. Lessons learned from close monitoring of polio eradication SIAs are will be applied to other campaigns being conducted in the African Region to accelerate control of other vaccine preventable diseases including cerebrospinal meningitis A, measles and yellow fever., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

In 2012, the World Health Assembly of the World Health Organization (WHO) declared the completion of polio eradication a programmatic emergency. Indigenous wild poliovirus (WPV) transmission remains uninterrupted in Nigeria (in the WHO African Region [AFR]) and in Afghanistan and Pakistan (in the WHO Eastern Mediterranean Region [EMR]). In the WHO AFR, multiple WPV outbreaks have occurred since 2003 after importation of indigenous West African WPV into 21 previously polio-free countries in a "WPV importation belt"* that extends across the continent. The Global Polio Eradication Initiative (GPEI) and WHO regional offices have used indicators of population immunity, surveillance quality, and other factors (e.g., high-risk subpopulations and proximity to WPV-affected countries) to assess the risk for outbreaks in polio-free countries and guide the implementation of risk mitigation measures to limit poliovirus transmission after WPV importation and prevent the emergence of circulating vaccine-derived poliovirus (cVDPV). Despite risk mitigation efforts, a polio outbreak, first confirmed in May 2013, is ongoing; as of September 10, a total of 178 WPV type 1 (WPV1) cases have been reported in Somalia† (163 cases), Kenya (14 cases) and Ethiopia (1 case), after importation of WPV1 of West African origin. This report summarizes steps taken by the GPEI to assess and mitigate the risks for outbreaks after WPV importation or the emergence of cVDPV in polio-free countries within the WHO AFR's "WPV importation belt." All countries will continue to have some level of risk for WPV outbreaks as long as endemic circulation continues in Afghanistan, Nigeria, and Pakistan.

By January 2012, 23 years after the Global Polio Eradication Initiative (GPEI) was begun, indigenous wild poliovirus (WPV) transmission had been interrupted in all countries except Afghanistan, Pakistan, and Nigeria. However, importation of WPV into 29 previously polio-free African countries during 2003-2011 led to reestablished WPV transmission (i.e., lasting >12 months) in Angola, Chad, Democratic Republic of the Congo (DRC), and Sudan (although the last confirmed case in Sudan occurred in 2009). This report summarizes progress toward polio eradication in Africa. In 2011, 350 WPV cases were reported by 12 African countries, a 47% decrease from the 657 cases reported in 2010. From 2010 to 2011, the number of cases decreased in Angola (from 33 to five) and DRC (from 100 to 93) and increased in Nigeria (from 21 to 62) and Chad (from 26 to 132). New WPV outbreaks were reported in 2011 in eight African countries, and transmission subsequently was interrupted in six of those countries. Ongoing endemic transmission in Nigeria poses a major threat to the success of GPEI. Vigilant surveillance and high population immunity levels must be maintained in all African countries to prevent and limit new outbreaks.

The Global Polio Eradication Initiative (GPEI) was launched in 1988. By 2006, transmission of indigenous wild poliovirus (WPV) was interrupted in all but four countries (Afghanistan, Pakistan, India, and Nigeria). Subsequently, 39 previously polio-free countries experienced outbreaks following importation of WPV, and transmission became reestablished in Angola, Chad, Democratic Republic of the Congo (DRC), and Sudan. This update summarizes progress toward polio eradication during 2010 and the first quarter of 2011. Worldwide, 1,291 WPV cases were reported in 2010, a 19% decrease from 2009; WPV type 3 (WPV3) cases decreased 92%, but WPV type 1 (WPV1) cases increased 145%. During 2010, 232 (18%) WPV cases were reported from the four polio-endemic countries; 159 (12%) cases were reported in Angola, Chad, and DRC; and 900 (70%) cases were reported in 13 countries, including two countries with outbreaks continuing from 2009 and 11 with new importations. During 2010, WPV cases in India and Nigeria decreased ≥94% compared with 2009. Outbreaks in Tajikistan and the Republic of the Congo (Congo) accounted for two thirds of cases (842) in 2010. All new outbreaks in 11 polio-free countries in 2010 were stopped or were on track to being stopped within 6 months of outbreak confirmation. During January--March 2011, substantially more WPV cases occurred in Chad, DRC, and Pakistan than during the same period of 2010. To further progress toward polio eradication and achieve the 2012 target of ending all WPV transmission, significant increases in resources and political commitment are needed.

In 1988, the World Health Assembly resolved to eradicate poliomyelitis globally by the year 2000. Dramatic progress toward this goal has occurred: three of the six WHO regions (Region of the Americas, European Region, and Western Pacific Region) are now polio free; and the number of polio-endemic countries decreased from over 125 in 1988 to 30 in 1999. Intensified efforts currently are underway to reach the target as soon as possible after 2000 in the three remaining polio-endemic WHO regions (African Region, Eastern Mediterranean Region, and South-East Asia Region). Even in polio-endemic regions, many countries are already polio free as the geographic extent of poliovirus shrinks while others. especially those experiencing conflict and war, pose substantial challenges to implementing the proven polio eradication strategies. Increasing attention and research now are devoted to the certification of polio eradication in the polio-free regions (that will include the first phase of implementing the Global Plan of Action for the laboratory containment of wild poliovirus) and formulating a policy for stopping all polio vaccination once eradication, containment, and global certification have been achieved. This report outlines the progress toward polio eradication and highlights some of the remaining issues and challenges that must be addressed before polio becomes a disease that future generations know only by history.

Despite daunting competing health priorities, Africa has made significant progress in polio control. Northern and Southern Africa appear to be polio-free and may shortly be certified as such; however, polio still remains endemic in West and Central Africa and the Horn of Africa. Countries "in difficult circumstancess", wracked by major civil wars, have particularly low routine vaccine coverage, although NIDS have been carried out during negotiated days of tranquillity. AFP surveillance has also improved, although the quality of stool specimens is still far from ideal. There is, nevertheless, an extraordinary political commitment to the eradication campaign. Lessons from the history of polio in the continent need to be heeded in designing end-game strategies. Obstacles on the path to successful eradication are undoubtedly more formidable on the African continent--perhaps the most serious of all are the continuing wars. International political commitment and focussed and empowering developmental aid are urgently needed.