Progress toward poliomyelitis eradication--Nigeria, 2005-2006

Only four countries (Afghanistan, India, Nigeria, and Pakistan) have never experienced interruption of poliovirus transmission. Nigeria had the largest number of cases in 2006, accounting for 1,129 (56%) of the 2,002 cases reported globally. However, major innovations to the national polio-eradication program in Nigeria were initiated in 2006. These innovations, if sustained, should advance the Global Polio Eradication Initiative. Nigeria (2006 population: 140 million) experienced a resurgence in wild poliovirus (WPV) transmission during 2003-2004 after a loss of public confidence in oral polio vaccine (OPV) and suspension of supplementary immunization activities (SIAs) in certain northern states. Subsequently, WPV spread within Nigeria and into 19 polio-free countries. Even after national SIAs recommenced, limited acceptance and ongoing operational problems resulted in low vaccination coverage and continued poliovirus transmission. The number of confirmed polio cases in Nigeria attributed to both WPV type 1 (WPV1) and type 3 (WPV3) increased from 782 in 2004 to 830 in 2005 and to 1,129 in 2006 (as of March 23, 2007). To increase the effectiveness of polio-eradication measures and community acceptance of vaccination, in 2006, health authorities in Nigeria introduced monovalent type 1 OPV (mOPV1) vaccine and changed the way SIAs were implemented. This report summarizes these new approaches and overall progress toward polio eradication in Nigeria during 2005-2006.     

Progress toward poliomyelitis eradication--Nigeria, January 2007-August 12, 2008

Nigeria is one of only four countries that have never interrupted poliovirus transmission (the others are Afghanistan, India, and Pakistan). A resurgence in wild poliovirus (WPV) transmission occurred in Nigeria during 2003-2004 after a loss of public confidence in oral poliovirus vaccine (OPV) and suspension of supplementary immunization activities (SIAs)* in several northern states. Subsequently, WPV spread within Nigeria and ultimately into 20 previously polio-free countries during 2003-2006. Even after national SIAs resumed, limited acceptance and ongoing operational problems resulted in low polio vaccination coverage and continued WPV transmission. Beginning in 2006, health authorities in Nigeria introduced new initiatives to control the spread of WPV, including a focus on interrupting type 1 WPV (WPV1) transmission and use of monovalent type 1 OPV (mOPV1) for most of the SIAs to increase vaccine effectiveness. Nigeria also instituted changes in SIA implementation to increase community acceptance of vaccination. Subsequently, 285 polio cases were reported in Nigeria in 2007, the lowest number since sensitive surveillance has been in place. As of August 12, 2008, confirmed polio cases reported in Nigeria totaled 556 (including 511 WPV1 cases), compared with 176 cases (53 WPV1) reported during the same period in 2007. This report updates overall progress toward polio eradication in Nigeria during 2007-2008. Given the increase in WPV transmission thus far in 2008, urgent measures are needed to reach all children during SIAs to bring WPV under control in Nigeria.     

Progress toward poliomyelitis eradication--Pakistan and Afghanistan, January 2005-May 2006

As of March 2006, wild poliovirus (WPV) remained indigenous in four countries: Afghanistan, India, Nigeria, and Pakistan. Since 2005, WPV-endemic countries in Asia have intensified their polio eradication measures through use of type 1 monovalent oral polio vaccine (mOPV1) and implementation of innovative social mobilization, communication, and vaccine-delivery strategies. This report describes polio eradication strategies in Afghanistan and Pakistan during January 2005-May 2006.     

Progress toward poliomyelitis eradication --- India, January 2009-October 2010

India is one of only four countries (including Afghanistan, Nigeria, and Pakistan) where wild poliovirus (WPV) transmission has never been interrupted. Historically, WPV transmission in India has centered largely in Uttar Pradesh and Bihar, two states with low routine vaccination coverage, large migrant and remote populations, and lower relative vaccine effectiveness than other areas of the country. However, during a 9-month period from November 2009 to August 2010, no WPV type 1 (WPV1) cases were reported in Uttar Pradesh or Bihar. This report summarizes the substantial progress made in India toward polio eradication during January 2009-October 2010, according to data reported as of December 4, and updates previous reports. During January-October 2010, only 40 WPV cases were confirmed in India, a 94% decrease from the 626 WPV cases confirmed during the same period in 2009; the decrease likely resulted, in large part, from the introduction of bivalent oral poliovirus vaccine types 1 and 3 (bOPV). Increasingly important contributors to WPV transmission are large migrant subpopulations; surveys have indicated that up to 11% of children aged <5 years in these subpopulations were missed during supplementary immunization activities (SIAs). Interruption of all WPV transmission in India will require maintaining high levels of immunity in Uttar Pradesh and Bihar and additional efforts directed toward children in migrant subpopulations that are not vaccinated as readily during SIAs.     

Progress toward poliomyelitis eradication--Nigeria, January 2004-July 2005

After the 1988 World Health Assembly resolution to eradicate polio, the number of countries where polio is endemic decreased from 125 in 1988 to six in 2003. However, the Global Polio Eradication Initiative faced critical challenges during 2003-2005, when a resurgence of polio cases occurred across Africa. Nigeria, the most populous country of the continent, experienced increased wild poliovirus (WPV) transmission throughout the country after suspension of supplementary immunization activities (SIAs) in certain northern states because of misconceptions regarding vaccine safety. The resurgence in Nigeria resulted in the spread of WPV during 2003-2005 into 18 countries that had been polio-free for 1 or more years, including three countries outside Africa. Transmission was reestablished and is ongoing in six of these countries. The Nigerian states that suspended campaigns subsequently resumed SIAs in 2004, in synchrony with SIAs being conducted in other countries across West and Central Africa. This report summarizes polio eradication activities and WPV circulation in Nigeria during January 2004-July 2005 and the actions under way to interrupt WPV transmission.     

Progress toward poliomyelitis eradication--India, January 2006-September 2007

India is one of four countries where wild poliovirus (WPV) transmission has never been interrupted (the others are Afghanistan, Nigeria, and Pakistan). An outbreak of poliomyelitis cases caused by WPV type 1 (WPV1) occurred in India in 2006, primarily in the northern states of Uttar Pradesh and Bihar, where polio remains endemic. This outbreak resulted in the greatest annual number of cases of poliomyelitis in India since 2002. In response, the Government of India and its partners implemented additional vaccination measures based on recommendations from the India Expert Advisory Group on Polio Eradication. These measures focused predominantly on use of monovalent oral poliovirus vaccine type 1 (mOPV1), which has higher efficacy against WPV1 than trivalent OPV (tOPV). As a result, WPV1 cases in India decreased approximately 84% to 66 cases during January-September 2007, compared with 405 cases during the corresponding period in 2006. In western Uttar Pradesh, a state in which multiple risk factors have made interruption of WPV transmission challenging, five WPV1 cases have been reported this year, compared with 299 during the same period in 2006. However, a WPV type 3 (WPV3) outbreak also has been reported, with 261 cases occurring through September 30, 2007, primarily in the northern states where polio remains endemic. This report summarizes progress toward polio eradication in India during January 2006-September 2007 and highlights the challenges and strategic adaptations of eradication measures.     

Progress toward poliomyelitis eradication--India, January 2005-June 2006

The global eradication of poliomyelitis has reached a critical stage. The disease remains endemic in only four countries (Afghanistan, India, Nigeria, and Pakistan), which have reported most of the cases in 2006. India is the most populous of the polio-endemic countries. Beginning in 2005, the Government of India (GOI) and its partners intensified eradication efforts by implementing additional immunization and surveillance strategies, including introduction of monovalent oral poliovirus vaccine types 1 and 3 (mOPV1 and mOPV3, respectively). The number of reported cases decreased from 134 in 2004 to 66 in 2005. However, cases have resurged in 2006; as of June 25, 2006, a total of 60 cases had been reported. Although intense local transmission continues in certain areas (i.e., western Uttar Pradesh [UP]), interruption of wild poliovirus (WPV) transmission in India is feasible with continued effective interventions. This report summarizes progress toward polio eradication in India from January 2005 through June 2006.     

Progress toward interruption of wild poliovirus transmission--worldwide, January 2007-April 2008

In 1988, the World Health Assembly resolved to eradicate poliomyelitis. Subsequently, the Global Polio Eradication Initiative reduced the global incidence of polio associated with wild polioviruses (WPVs) from an estimated 350,000 cases in 1988 to 1,997 reported cases in 2006 and reduced the number of countries that have never succeeded in interrupting WPV transmission from 125 to four (Afghanistan, India, Nigeria, and Pakistan). Type 2 WPV (WPV2) circulation was last observed in October 1999. In February 2007, the World Health Organization (WHO) convened a stakeholders meeting to agree on an accelerated polio-eradication effort to be used during 2007-2008 and establish milestones to monitor progress. Programmatic strategies implemented in 2007 included expanded use of type 1 monovalent oral poliovirus vaccine (OPV) (mOPV1) to eliminate type 1 WPV (WPV1) transmission before type 3 WPV (WPV3) and targeted use of type 3 monovalent OPV (mOPV3) in selected areas. This report summarizes these strategies and overall progress toward reaching the milestones, including a decline in the overall number of WPV cases to 1,310 in 2007 and substantial progress toward interruption of WPV1 circulation in India in 2008.     

Progress toward poliomyelitis eradication--India, January 2004-May 2005

Since 1988, the global incidence of polio has decreased by more than 99%, and three World Health Organization (WHO) regions (Americas, Western Pacific, and European) have been certified as polio-free . India, the largest of the six countries where polio remains endemic, experienced a large polio outbreak (1,600 cases) in 2002. Since then, the Government of India (GOI) has accelerated its polio eradication activities by increasing the number and quality of supplementary immunization activities (SIAs), which reduced the number of reported cases to 225 in 2003, 134 in 2004, and 18 in 2005 (as of June 18). During 2004 and early 2005, taking advantage of the geographic restriction of wild poliovirus (WPV) circulation, GOI and its partners launched several immunization and surveillance strategies to maximize the probability of eliminating poliovirus transmission in India. With continued high-quality interventions, interruption of WPV transmission in India by the end of 2005 appears feasible. This report summarizes progress toward polio elimination during January 2004-May 2005 toward that end.     

Polio eradication in the African Region on course despite public health emergencies

The World Health Organization, African Region is heading toward eradication of the three types of wild polio virus, from the Region. Cases of wild poliovirus (WPV) types 2 and 3 (WPV2 and WPV3) were last reported in 1998 and 2012, respectively, and WPV1 reported in Nigeria since July 2014 has been the last in the entire Region. This scenario in Nigeria, the only endemic country, marks a remarkable progress. This significant progress is as a result of commitment of key partners in providing the much needed resources, better implementation of strategies, accountability, and innovative approaches. This is taking place in the face of public emergencies and challenges, which overburden health systems of countries and threaten sustainability of health programmes. Outbreak of Ebola and other diseases, insecurity, civil strife and political instability led to displacement of populations and severely affected health service delivery. The goal of eradication is now within reach more than ever before and countries of the region should not relent in their efforts on polio eradication. WHO and partners will redouble their efforts and introduce better approaches to sustain the current momentum and to complete the job. The carefully planned withdrawal of oral polio vaccine type II (OPV2) with an earlier introduction of one dose of inactivated poliovirus vaccine (IPV), in routine immunization, will boost immunity of populations and stop cVDPVs. Environmental surveillance for polio viruses will supplement surveillance for AFP and improve sensitivity of detection of polio viruses.     

Progress toward poliomyelitis eradication--Nigeria, January 2003-March 2004

Since the 1988 World Health Assembly resolution to eradicate poliomyelitis, three World Health Organization (WHO) regions (Americas, Western Pacific, and European) have been certified polio-free, and the number of countries where polio is endemic has decreased from 125 in 1988 to six in 2003 (Afghanistan, Egypt, India, Niger, Nigeria, and Pakistan). In 2003, Nigeria, the most populous country of the African continent (2003 population projected from 1991 census report: 125 million), reported 355 wild poliovirus (WPV) cases, accounting for 45% of cases reported globally and >80% of cases reported from the African Region (AFR). This report summarizes progress toward polio eradication in Nigeria during January 2003-March 2004. The findings indicate the urgent need to implement high-quality supplementary immunization activities (SIAs) in Nigeria to interrupt ongoing WPV transmission.     

The global polio eradication initiative: lessons learned and prospects for success

Following the rapid progress towards interrupting indigenous wild poliovirus transmission in the Americas in the early 1980s, the Global Polio Eradication Initiative (GPEI) was launched with a resolution of the World Health Assembly (WHA) in 1988. The GPEI built on many lessons learned from smallpox eradication, including the large-scale deployment of technical assistance, implementing agendas of innovation and research and the use of professionally planned and guided advocacy. By the year 2000, the incidence of polio globally had decreased by 99% compared with the estimated >350,000 cases reported from 125 endemic countries in 1988. By 2002, three WHO Regions (the Americas, Western Pacific and European Regions) had been certified polio-free. By 2005, transmission of indigenous wild poliovirus (WPV) had been interrupted in all but 4 'endemic' countries: India, Nigeria, Pakistan and Afghanistan, where eradication efforts effectively stalled. WPV exported from northern Nigeria and northern India subsequently caused >50 outbreaks and paralysed >1500 children in previously polio-free countries across Asia and Africa. In each of the four remaining polio-endemic countries different challenges, or a combination of factors, prevented to build up sufficient levels of population immunity to stop transmission. Consequently, specific strategies were increasingly tailored to each setting. A new 2010-2012 GPEI Strategic Plan was developed which brought together several approaches to overcome the remaining hurdles to eradication, including the large-scale use of bivalent oral poliovaccine (bOPV) in supplementary immunization activities (SIAs). By the end of 2010, the impact of the new GPEI Strategic Plan 2010-2012 was apparent. Compared to 2009, the number of new polio cases in 2010 fell by 95% in both northern Nigeria and northern India, the world's largest remaining reservoirs of indigenous WPVs. By mid-2011, India had not reported a polio case for more than 5 months, and in Nigeria, endemic transmission appeared to be restricted to the north-east and north-west corners of the country. While polio cases due to WPV type 3 were still being detected in west and central Africa, the overall level of WPV3 transmission globally was at an all-time low. Uncontrolled WPV transmission appeared to be restricted to Chad and Pakistan, which increasingly represented the greatest risks to the GPEI. Although insufficient financing continued to be a major concern, political support for completing polio eradication in polio-infected countries was stronger than ever by mid-2011. While continued transmission in some areas, particularly in Pakistan and Chad, still had to be controlled as a matter of urgency, there were real opportunities to achieve new landmarks in polio eradication, especially in the key WPV reservoirs of India and Nigeria, setting the stage for polio to soon follow smallpox into the history books.     

Progress toward poliomyelitis eradication--Pakistan and Afghanistan, 2007

Of the four countries worldwide where wild poliovirus (WPV) transmission has never been interrupted, Pakistan and Afghanistan are considered a single epidemiologic block. Use of intense poliomyelitis eradication measures, including close coordination between the two countries and increased use of monovalent oral poliovirus vaccines (mOPVs) against type 1 WPV (WPV1) and type 3 WPV (WPV3), has reduced WPV transmission to historically low levels. However, despite these efforts, in 2007 both types of WPV continued to circulate in areas of Pakistan and Afghanistan. Ongoing conflicts and security concerns in remote areas with rugged terrain limit access to children and decrease vaccination coverage from routine and supplementary immunization activities (SIAs) in border areas of both countries where WPV transmission is endemic. In other WPV-endemic areas of Pakistan, where security and access concerns do not exist, operational problems in implementing SIAs resulted in inadequate vaccination of children, which failed to interrupt WPV transmission. This report updates previous reports and describes polio eradication activities in Pakistan and Afghanistan during January-December 2007 (data as of March 22, 2008). Further progress toward polio eradication will require continued measures to address security concerns in portions of both countries and problems with implementing SIAs in secure areas of Pakistan.     

Update on vaccine-derived polioviruses--worldwide, January 2006-August 2007

In 1988, the World Health Assembly resolved to eradicate poliomyelitis worldwide. Subsequently, the Global Polio Eradication Initiative of the World Health Organization (WHO) reduced the global incidence of polio associated with wild polioviruses (WPVs) from an estimated 350,000 cases in 1988 to 1,998 reported cases in 2006 and reduced the number of countries that have never succeeded in interrupting WPV transmission to four (Afghanistan, India, Nigeria, and Pakistan). However, because vaccine-derived polioviruses (VDPVs) can produce polio outbreaks in areas with low rates of Sabin oral poliovirus vaccine (OPV) coverage and can replicate for years in immunodeficient persons, enhanced strategies are needed to limit emergence of VDPVs and stop all use of OPV once WPV transmission is eliminated. This report updates a summary of VDPV activity published in 2006 and describes VDPVs detected during January 2006-August 2007.     

Progress toward interruption of wild poliovirus transmission--worldwide, January 2011-March 2012

In January 2012, completion of polio eradication was declared a programmatic emergency for global public health by the Executive Board of the World Health Organization (WHO). Despite major progress since the launch of the Global Polio Eradication Initiative (GPEI) in 1988, circulation of indigenous wild poliovirus (WPV) continues in three countries (Afghanistan, Nigeria, and Pakistan). India has not reported a polio case since January 2011, and is considered polio-free since February 2012. This report highlights progress toward global polio eradication during January 2011-March 2012. The number of polio cases reported globally decreased by 52%, from 1,352 in 2010 to 650 in 2011. Those 650 cases included 341 (53%) reported from the four polio-endemic countries (Afghanistan, India, Nigeria, and Pakistan), 230 (35%) from previously polio-free countries in which WPV importations led to reestablished transmission for ≥12 months (Angola, Chad, and Democratic Republic of the Congo [DRC]), and 79 (12%) from nine countries affected by outbreaks. Compared with 2010, WPV cases increased in 2011 in Afghanistan (69%), Nigeria (66%), and Pakistan (27%), but decreased in India (98%). During January-March 2012, 59% fewer cases were reported worldwide (as of May 15) compared with the same period in 2011, and all cases in 2012 have been reported from Afghanistan, Chad, Nigeria, and Pakistan. Although progress toward polio eradication was substantial in 2011, persistent WPV circulation in 2012, particularly in Nigeria and Pakistan, poses an ongoing threat to eradication efforts, underscoring the need for emergency measures by polio-affected countries and those at risk for outbreaks after importation.     

Progress toward poliomyelitis eradication---India, January 2010--September 2011

The Global Polio Eradication Initiative was launched in 1988. In 1995, when eradication activities were initiated in India, an estimated 50,000 polio cases were occurring each year. By 2006, transmission of indigenous wild poliovirus (WPV) had been interrupted in all countries except India, Afghanistan, Pakistan, and Nigeria. During 2006--2009, India annually reported 559 to 874 cases of confirmed WPV, with cases centered in the northern states of Uttar Pradesh and Bihar. These cases accounted for 43% of confirmed cases of WPV reported worldwide during this period. However, in 2010, only 42 WPV cases were reported in India, and in 2011, only one WPV case had been confirmed as of October 31. This report updates previous reports and summarizes progress toward polio eradication in India during January 2010--September 2011. Throughout India, the most recent confirmed WPV type 3 (WPV3) case occurred on October 22, 2010, in Jharkhand, and the most recent confirmed WPV type 1 (WPV1) case occurred on January 13, 2011, in West Bengal; WPV2 has not been reported in India since 1999. Importation of WPV into India is a risk, and undetected low-level WPV transmission is a possibility, requiring high vaccination coverage in all states, continued focus on children in migrant and underserved populations, sensitive surveillance for prompt detection of any WPV, and preparedness to mount a robust emergency vaccination campaign in response to any WPV cases.     

Progress toward interruption of wild poliovirus transmission--worldwide, January 2010-March 2011

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.     

World Witnesses a Tumultuous Year while India Reports an Eventful Decade in the Long Story of Polio Eradication

With recent outbreaks in Syria and Horn of Africa, silent circulation of wild poliovirus type 1 (WPV1) in Israel, West Bank, and Gaza, and fresh spate of violence against vaccinators and their security personnel in Pakistan, the world is facing a turbulent final ascent to the summit of polio eradication. On the positive side, we may also be witnessing the end of wild poliovirus type 3 (WPV3) and defused programmatic crisis caused by funding gaps, while India registers third consecutive polio-free year. Having a cogent endgame plan 2013-2018, informed by some cardinal lessons learned from an eventful decade in India, is also a very significant development. Now, there is a parallel pursuit against WPV and vaccine-derived poliovirus (VDPV). Endgame would also involve integration of at least one dose of affordable inactivated polio vaccine (IPV) to up-scaled routine immunization (RI), switch from trivalent oral polio vaccine (tOPV) to bivalent oral polio vaccine (bOPV) in 144 countries before 2018, stockpiling of mOPV, and simultaneous global cessation of bOPV before 2020. Role of antivirals in post-eradication era is still unclear. Some specific threats emerging at this stage are as follows: Global buildup of new birth cohorts in non-endemic countries with weak RI and downscaled supplementary immunization activities (SIAs), tremendous pressure on peripheral health workers, and fatigued systems. Cultural resistance to transnational programs is taking a violent shape in some areas. Differential interpretations of ‘right to say no’, on both sides of the divide, are damaging a global cause. Amidst all these concerns, let us not forget to underline the sacrifice made by frontline vaccinators working in some of the most challenging circumstances.     

Progress toward poliomyelitis eradication--Nigeria,January 2002--March 2003

Since 1988, when the World Health Assembly resolved to eradicate poliomyelitis globally, the annual estimated incidence of polio has decreased >99%. Nigeria is the most populous country in Africa (estimated 2000 population: 127 million) and a major poliovirus reservoir. This report summarizes progress toward polio eradication in Nigeria during January 2002--March 2003, highlighting progress in acute flaccid paralysis (AFP) surveillance and evidence of wild poliovirus (WPV) circulation in areas of lower vaccination coverage. The findings underscore the importance of achieving high-quality supplementary immunization activities (SIAs).     

Global Polio Eradication Initiative Strategic Plan, 2004

Since the 1988 World Health Assembly resolution to eradicate poliomyelitis, the number of polio-endemic countries has decreased from 125 in 1988 to six in 2003 (i.e., Afghanistan, Egypt, India, Niger, Nigeria, and Pakistan), and the number of cases reported worldwide has decreased from approximately 350,000 to 682. In 2003, approximately 90% of cases were reported from Nigeria (305), India (220), and Pakistan (99); epidemiologic and virologic data demonstrated focal endemic transmission in Afghanistan and Niger, with repeated importations from Pakistan and Nigeria, respectively, and localized transmission in Egypt. On January 15, 2004, the World Health Organization (WHO) released an updated Global Polio Eradication Initiative Strategic Plan outlining activities required to 1) interrupt poliovirus transmission globally, 2) achieve global certification of polio eradication, and 3) prepare for global cessation of childhood vaccination with oral poliovirus vaccine (OPV). The discontinuation of mass vaccination campaigns in the majority of polio-free countries has left these areas vulnerable to importations of wild poliovirus (WPV) from the remaining countries in which polio is endemic. For polio to be eradicated, all remaining poliovirus reservoirs must be eliminated.