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Progress towards Polio Eradication Worldwide, 2015-2016

Friday, 13th of May 2016

Progress towards Polio Eradication Worldwide, 2015-2016

Discussion below; full text is at http://www.who.int/wer/2016/wer9119.pdf?ua=1

Discussion

Significant gains towards polio eradication were made in 2015, with a 79% decrease in the number of cases reported worldwide compared with levels in 2014. The removal of Nigeria from the list of polio-endemic countries in 2015 heralds the opportunity for the WHO African Region to join the Region of the Americas, and the South-East Asia, Western Pacific, and European Regions, as the fifth of 6 WHO regions to be certified free of indigenous WPV. This will occur after a minimum of 3 years with sensitive AFP surveillance performance. In addition, the GCCs declaration of the eradication of WPV2 in 2015, and the absence of reported circulation of WPV3 since 2012, allows focus on WPV1 as the only circulating type of WPV in the world, remaining endemic only in Afghanistan and Pakistan. WHO considers the continued transmission of WPV1 across the borders of both countries to constitute a public health emergency of international concern under the 2005 International Health Regulations.10 Continued focus on identifying groups of children missed with polio vaccination through routine immunization or SIAs, improving SIA quality, and increasing AFP surveillance sensitivity in these countries is needed to stop WPV transmission. Afghanistan had a substantial reduction in WPV cases during 2015. The majority of cases were reported from Nangarhar province in eastern Afghanistan, which borders Pakistan, and genetically linked to cases in Pakistan, emphasizing the need for continued improvement of cross-border coordination and SIA synchronization. Although some children are missed during SIAs in Afghanistan due to inaccessibility and security concerns, the majority of children are missed during SIAs due to managerial issues, including inadequate microplanning and campaign implementation. The southern region, although accessible for programme implementation, has very limited access for supervision and monitoring. Innovative approaches, such as the fourth-day revisit strategy during campaigns, the use of permanent vaccination teams dedicated to regular house-to-house visits, or vaccination at transit points leading in and out of insecure areas, should continue to be regularly used to reach all missed children.

The recent establishment of Emergency Operations Centers (EOCs) at the national level and in 3 critical regions enhances the countrys capacity to plan and implement polio eradication activities. Progress in Pakistan accounted for the majority of the dramatic drop in polio cases in 2015–2016. The significant gains made are, at least in part, attributable to the establishment of a cohesive national EOC that implemented a rigorous national polio eradication emergency action plan. However, operational problems with vaccinating all children during SIAs, ensuring programme accountability at all levels, and ongoing movement of unvaccinated children across the Afghanistan/Pakistan border constitute the main challenges facing the polio programme in Pakistan. Although no WPV cases were detected in non-endemic countries, 7 countries reported cVDPV outbreaks during 2015–2016, demonstrating the risk of VDPV emergence associated with low OPV coverage. In each of these countries certain factors, such as the concurrent Ebola epidemic in Guinea and instability in vaccine procurement and public trust in Ukraine, impacted negatively on the quality of routine immunization services and allowed the bemergence and spread of the outbreaks. More than 95% of cVDPV cases since 2006 have been caused by cVDPV2. Therefore, in April 2016, in view of the certification of the eradication of WPV type 2, 154 of 155 OPV-using WHO Member States and territories discontinued the use of type 2 Sabin vaccine by switching from tOPV to bOPV for routine and supplementary immunization.11 The global switch from trivalent to bivalent OPV will markedly reduce the risk associated with type 2 cVDPV emergence and transmission; however, the global community must continue to support strong routine immunization service delivery to curb the risk of type 1 or type 3 cVDPV outbreaks or transmission following WPV importation from endemic countries into polio-free areas. With progress made in 2015–2016 towards interruption of WPV transmission in Afghanistan and Pakistan, the world is closer than ever before to the eradication of polio. Continued cooperative efforts between the 2 countries is essential. In addition, it is urgent that all countries and Global Polio Eradication Initiative (GPEI) partners collaborate to implement the GPEIs Polio Eradication and Endgame Strategic Plan for 2013–201812 in order to end WPV and VDPV transmission.

12 Global Polio Eradication Initiative. Polio eradication and endgame strategic plan 2013–2018. Geneva, Switzerland: Global Polio Eradication Initiative; 2013. Available at: http://www.polioeradication.org/Portals/0/Document/Resources/StrategyWork/PEESP_EN_US.pdf. 11