Polio-endemic Countries Research Articles

Acute Flaccid Paralysis Surveillance system Evaluation, Oyo state, Nigeria; 2008-2014

ObjectiveWe evaluated the AFP surveillance system in Oyo State to assessits attributes and determine if it was meeting its set objectives.IntroductionIn September, 2015, Nigeria was delisted from the list of polioendemic countries globally. To be certified polio free, the countrymust attain and maintain certification standard Acute Flaccid Paralysis(AFP) surveillance for additional two-years. In Oyo State, no case ofWild Polio Virus (WPV) has been reported since February, 2009.MethodsWe used the Centre for Disease Control and Prevention updatedguidelines for evaluating public health surveillance system.We conducted a retrospective review of AFP surveillance databetween 1stJanuary, 2008 and 31stDecember, 2014. We conductedin-depth interviews with identified stakeholders. Semi-structuredquestionnaires were administered to Disease Surveillance andNotification Officers (DSNOs) and AFP focal persons. Univariateanalysis was performed by calculating frequencies, means andproportions using Microsoft Excel 2010.ResultsThe case definition of AFP and the tools for reporting are simple.Of the 897 AFP cases detected during the period under review(2008-2014), 20 (2.2%) were laboratory confirmed WPV. Thesensitivity of the system between 2008 and 2014 measured by theAnnualized Non-Polio AFP (NPAFP) rate was consistently abovethe target. of≥2/100,000 population(Mean=3.96, Standard deviation(SD): 0.48). The mean NPAFP rate for underperforming LGAs duringthe review period was 1.6, SD: 0.31. The mean Stool adequacy andTimeliness were 91.43% (SD: 18.3) and 91.3% (SD: 20.3) abovethe target of≥80% respectively. The mean Data quality was 90%(target is≥90; SD: 3.8). Positive Predictive Value (PVP) was 2%(2008 -2009), and 0% in 2010-2014.ConclusionsThe Oyo State AFP surveillance system is simple, flexible,sensitive and meeting its set objectives. However, PVP was low andthe system’s operating conditions are not stable. All the LGAs, at onepoint during the period under review did not meet the NPAFP andNPENT rates. We recommended that more logistic support shouldbe provided for non-performing LGAs to improve case reporting,investigation, and response. DSNOs should be re -sensitized onreverse cold chain, so as to improve the NPENT rate

Does India need national child mortality surveillance project to reduce child mortality? An opportunity from National Polio Surveillance Project (NPSP)

In 2015, India had 20 percent share of global under-five deaths (1.2 million), highest number of deaths in the world. In the era of Sustainable Development Goal (SDG), to accomplish goal 3, target 3.2 to reduce child mortality to 25 per 1,000 live births, India needs to accelerate to achieve the same. India was taken off from the list of polio endemic countries by World Health Organization in February 2012. In 1997 the National Polio Surveillance Project (NPSP) was established as a joint partnership between the World Health Organization and the Ministry of Health and Family Welfare (MoHFW), Government of India. As in Polio eradication program interaction between the health care providers and Surveillance Medical Officer (SMO), had provided the foundation for successful Acute Flaccid Paralysis (AFP) surveillance, same opportunity can be used for every child death. Each child death reported by reporting unit (RU) needs to be investigated in case investigation form (CIF) and the factors related to continuum of care for maternal, newborn and child health whichever responsible for child death needs to be identified for action. Another aim of this project will be to capture each and every child death occurring in the district and identifying the high risk blocks and accordingly training of health workers and private practitioner can be undertaken for capacity building. The feedback of factors identified for child death can be given to health officers of concerned district and same can be discussed in District Task Force meeting, so appropriate corrective action is initiated; also same can be reviewed at regional, state and national level meetings. National Child Mortality Surveillance Project can take the advantage of network of SMO already available with NPSP along with training modules and forms.

A spatial model of Wild Poliovirus Type 1 in Kano State, Nigeria: calibration and assessment of elimination probability

BackgroundSince the launch of the Global Polio Eradication Initiative, all but three countries (Nigeria, Pakistan, and Afghanistan) have apparently interrupted all wild poliovirus (WPV) transmission, and only one of three wild serotypes has been reported globally since 2012. Countrywide supplemental immunization campaigns in Nigeria produced dramatic reduction in WPV Type 1 paralysis cases since 2010 compared to the 2000’s, and WPV1 has not been observed in Nigeria since July 24, 2014. This article presents the development and calibration of a spatial metapopulation model of wild poliovirus Type 1 transmission in Kano State, Nigeria, which was the location of the most recent WPV1 case and 5 out of 6 of the reported WPV1 paralytic cases in Nigeria in 2014.MethodsThe model is calibrated to data on the case counts and age at onset of paralysis from 2003–2009. The features of the data drive model development from a simple susceptible-exposed-infective-recovered (SEIR) model to a spatial metapopulation model featuring seasonal forcing and age-dependent transmission. The calibrated parameter space is then resampled, projected forward, and compared to more recent case counts to estimate the probability that Type 1 poliovirus has been eliminated in Kano state.ResultsThe model indicates a 91 % probability that Type 1 poliovirus has been eliminated from Kano state as of October 2015. This probability rises to >99 % if no WPV1 paralysis cases are detected for another year. The other states in Nigeria have experienced even longer case-free periods (the only other state with a WPV1 case was Yobe, on April 19, 2014), and Nigeria is the last remaining country in Africa to experience endemic WPV1 transmission, so these results can be interpreted as an upper bound on the probability that WPV1 transmission is currently interrupted continent-wide.ConclusionsWhile the results indicate optimism that WPV1 transmission has been interrupted in Kano state, the model also assumes that frequent SIAs with high coverage continue to take place in Kano state through the end of the certification period. We conclude that though WPV1 appears to be on the brink of continent-wide elimination (WHO officially removed Nigeria from the list of polio-endemic countries on September 25, 2015), it is important for the polio program to maintain vigilance in surveillance and vaccination activities to prevent WPV1 resurgence through the WHO’s 3-year eradication certification period.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-016-1817-3) contains supplementary material, which is available to authorized users.

Poliovirus seroprevalence before and after interruption of poliovirus transmission in Kano State, Nigeria

IntroductionIn September 2015, Nigeria was removed from the list of polio-endemic countries after more than 12months had passed since the detection of last wild poliovirus case in the country on 24 July 2014. We are presenting here a report of two polio seroprevalence surveys conducted in September 2013 and October 2014, respectively, in the Kano state of northern Nigeria. MethodsHealth facility based seroprevalence surveys were undertaken at Murtala Mohammad Specialist Hospital, Kano. Parents or guardians of children aged 6–9months, 36–47months, 5–9years and 10–14years in 2013 and 6–9months and 19–22months (corresponding to 6–9months range at the time of 2013 survey) in 2014 presenting to the outpatient department, were approached for participation, screened for eligibility and asked to provide informed consent. A questionnaire was administered and a blood sample collected for polio neutralization assay. ResultsAmong subjects aged 6–9months in the 2013 survey, seroprevalence was 58% (95% confidence interval [CI] 51–66%) to poliovirus type 1, 42% (95% CI 34–50%) to poliovirus type 2, and 52% (95% CI 44–60%) to poliovirus type 3. Among children 36–47months and older, seroprevalence was 85% or higher for all three serotypes. In 2014, seroprevalence in 6–9month infants was 72% (95% CI 65–79%) for type 1, 59% (95% CI 52–66%) for type 2, and 65% (95% CI 57–72%) for type 3 and in 19–22months, 80% (95% CI 74–85%), 57% (49–63%) and 78% (71–83%) respectively. Seroprevalence was positively associated with history of increasing oral poliovirus vaccine doses. ConclusionsThere was significant improvement in seroprevalence in 2014 over the 2013 levels indicating a positive impact of recent programmatic interventions. However the continued low seroprevalence in 6–9month age is a concern and calls for improved immunization efforts to sustain the polio-free Nigeria.

Contribution of polio eradication initiative to strengthening routine immunization: Lessons learnt in the WHO African region

BackgroundImportant investments were made in countries for the polio eradication initiative. On 25 September 2015, a major milestone was achieved when Nigeria was removed from the list of polio-endemic countries. Routine Immunization, being a key pillar of polio eradication initiative needs to be strengthened to sustain the gains made in countries. For this, there is a huge potential on building on the use of polio infrastructure to contribute to RI strengthening. MethodsWe reviewed estimates of immunization coverage as reported by the countries to WHO and UNICEF for three vaccines: BCG, DTP3 (third dose of diphtheria-tetanus toxoid- pertussis), and the first dose of measles-containing vaccine (MCV1).We conducted a systematic review of best practices documents from eight countries which had significant polio eradication activities. ResultsImmunization programmes have improved significantly in the African Region. Regional coverage for DTP3 vaccine increased from 51% in 1996 to 77% in 2014. DTP3 coverage increased >3 folds in DRC (18–80%) and Nigeria from 21% to 66%; and >2 folds in Angola (41–87%), Chad (24–46%), and Togo (42–87%). Coverage for BCG and MCV1 increased in all countries. Of the 47 countries in the region, 18 (38%) achieved a national coverage for DTP3 ⩾90% for 2years meeting the Global Vaccine Action (GVAP) target. A decrease was noted in the Ebola-affected countries i.e., Guinea, Liberia and Sierra Leone. ConclusionsPEI has been associated with increased spending on immunization and the related improvements, especially in the areas of micro planning, service delivery, program management and capacity building. Continued efforts are needed to mobilize international and domestic support to strengthen and sustain high-quality immunization services in African countries. Strengthening RI will in turn sustain the gains made to eradicate poliovirus in the region.

Intensified Local Resource Mobilization for the Polio Eradication Initiative: The Experience of World Health Organization in Nigeria During 2008-2015.

Background. Since the World Health Assembly (WHA) resolved in 1988 to eradicate poliovirus, several rounds of immunization campaigns have been conducted by member states. By 2000, with the support of the Global Polio Eradication Initiative (GPEI) partners, the number of polio cases decreased by 99%. Eradicating the remaining 1% proved to be more challenging. Although the GPEI, being the largest public health project, required >$9 billion between 1988 and 2012, economic analysis showed the estimated incremental net benefits of $40 billion–$50 billion between 1988 and 2035. In 2012, the WHA declared that the completion of poliovirus eradication is a programmatic emergency for global public health. Nigeria, as one of 3 remaining polio-endemic countries, developed an emergency plan to interrupt the transmission of poliovirus. The plan included the introduction or scale-up of various new innovations and strategies, which had substantial financial implication.Methods. This is a retrospective study to document the intensified resource mobilization efforts made by the World Health Organization (WHO) in Nigeria to meet the increased financial requirements and bridge the remaining gap in funding. In addition to the established coordination platforms, the WHO Nigeria Country Office team directly engaged with national authorities, donors, and partners throughout the process of resource requirement analysis, project appraisals, proposal development, and implementation of activities, joint monitoring, and evaluation exercises. The office strengthened its capacity for direct funds disbursement and systematic implementation of a rigorous accountability framework.Results. Between 2008 and May 2015, $538 million was mobilized locally, of which 82% was mobilized since 2012. The percentage of the total funding requirements that were locally mobilized averaged 31% between 2008 and 2011 and increased to 70% between 2012 and May 2015. During the same period, the WHO Nigeria Country Office team produced and submitted 102 grant reports and facilitated >20 joint project assessment exercises.Discussion. The polio program in Nigeria has achieved unprecedented gains, despite prevailing security and operational challenges, with no case of wild poliovirus infection since July 2014. Through rigorous, transparent, and accountable funds management practice, the WHO country office in Nigeria gained donors' confidence. The locally mobilized funds have made a remarkable contribution to the successful implementation of the strategies set out in the polio emergency plan. We face the challenges of a narrow donor-base, donor fatigue, and competition among other emerging agencies joining the polio eradication initiative efforts over the last few years. We actively engage the national authorities and partners for effective coordination of the polio eradication initiative program and harmonization of resources, using the existing platforms at national, state, and local levels. We recommend strengthening the local resource mobilization machinery and broadening the donor base, to support the polio endgame strategy. Such efforts should also be adopted to support routine immunization, introduction of new vaccines, and strengthening of health systems in the country as part of polio legacy planning.

Role of Serial Polio Seroprevalence Studies in Guiding Implementation of the Polio Eradication Initiative in Kano, Nigeria: 2011-2014.

Background. Nigeria was one of 3 polio-endemic countries before it was de-listed in September 2015 by the World Health Organization, following interruption of transmission of the poliovirus. During 2011–2014, Nigeria conducted serial polio seroprevalence surveys (SPS) in Kano Metropolitan Area, comprising 8 local government areas (LGAs) in Kano that is considered very high risk (VHR) for polio, to monitor performance of the polio eradication program and guide the program in the adoption of innovative strategies.Methods. Study subjects who resided in any of the 8 local government areas of Kano Metropolitan Area and satisfied age criteria were recruited from patients at Murtala Mohammed Specialist Hospital (Kano) for 3 seroprevalence surveys. The same methods were used to conduct each survey.Results. The 2011 study showed seroprevalence values of 81%, 75%, and 73% for poliovirus types 1, 2, and 3, respectively, among infants aged 6–9 months age. Among children aged 36–47 months, seroprevalence values were greater (91%, 87%, and 85% for poliovirus types 1, 2, and 3, respectively).In 2013, the results showed that the seroprevalence was unexpectedly low among infants aged 6–9 months, remained high among children aged 36–47 months, and increased minimally among children aged 5–9 years and those aged 10–14 years. The baseline seroprevalence among infants aged 6–9 months in 2014 was better than that in 2013.Conclusions. The results from the polio seroprevalence surveys conducted in Kano Metropolitan Area in 2011, 2013, and 2014 served to assess the trends in immunity and program performance, as well as to guide the program, leading to various interventions being implemented with good effect, as evidenced by the reduction of poliovirus circulation in Kano.

Sensitivity of Acute Flaccid Paralysis Surveillance in Nigeria (2006-2015)

Background: Nigeria has made tremendous progress towards polio eradication. The country was removed from the list of polio endemic countries by the World Health Organization (WHO) in September 2015. The last cases of wild poliovirus (WPV) and circulating vaccine derived poliovirus (cVDPV) from acute flaccid paralysis (AFP) cases had onset of paralysis in July 2014 and May 2015 respectively. The country has completed the phase I of laboratory containment of poliovirus activities, has achieved and maintained certification standard surveillance and is now in the process of ensuring adequate documentation preparatory to certification in 2017. Methods: We conducted a retrospective review of AFP surveillance performance in Nigeria between 2006 and 2015 from the AFP database at the WHO Country Office. We also reviewed rapid surveillance assessment reports conducted in various states of the country within the reporting period to identify surveillance strengths and gaps as well as recommendations put forward to improve polio surveillance performance. Results: The sensitivity of AFP surveillance in Nigeria increased consistently over the past 10 years. The number of confirmed and polio compatible cases has reduced significantly during the reporting period. AFP reporting sites have been prioritized for active surveillance and community informants have been engaged and cut across several key stakeholders in community health care delivery system. Conclusion: The AFP surveillance performance in Nigeria during the reporting period demonstrated high level of sensitivity that can be relied upon to timely detect polio outbreak. Residual surveillance gaps at sub national levels however exist and must be closed to be able to identify remaining areas of poliovirus transmission should such exist as well as promptly detect possible cases of importation. Quality surveillance is also required for certification.

Polio, public health, and the new pathologies of militancy in Pakistan

Since 2005, Pakistan has witnessed a net increase in polio, reaching a 15-year crest in 2014 when 306 cases were reported. Pakistan, along with Afghanistan, is one the remaining two polio-endemic countries. The numbers of cases reported in Pakistan in 2014 were far in excess of Afghanistan (28) and Nigeria (6). This paper focuses on the endemic militancy plaguing the country that has recently created grave obstacles for countrywide polio eradication. We argue that the relationship between polio and militancy in Pakistan has had two facets. First, polio vaccination efforts have become a casualty of militancy: over the last decade, polio vaccination was periodically banned in militant strongholds, large cohorts of children remained unvaccinated in remote frontier regions as vaccinators were unable to reach them, and anti-vaccination discourses in many parts of the country deterred others from vaccinating their children. The second relationship between the presence of polio in Pakistan and militancy is one where state-led polio vaccination efforts became a target of militancy. This was through the deliberate killing of polio workers; since July 2012, 71 contractual government employees tasked with administering polio vaccines have been killed, posing impediments to vaccine coverage. This paper concludes that in addition to implementing policies to improve vaccination coverage, endemic militancy must be addressed before polio can be eradicated.

Progress Toward Poliomyelitis Eradication--Nigeria, January 2014-July 2015.

Since the 1988 launch of global poliomyelitis eradication efforts, four of the six World Health Organization (WHO) regions have been certified polio-free. Nigeria is one of only three countries, along with Afghanistan and Pakistan, where transmission of wild poliovirus (WPV) has never been interrupted. During 2003-2013, northern Nigeria served as a reservoir for WPV reintroduction into 26 previously polio-free countries. In 2012, the Nigerian government launched a national polio eradication emergency plan to intensify efforts to interrupt WPV transmission. This report describes polio eradication activities and progress in Nigeria during January 2014-July 2015 and updates previous reports. No WPV cases have been reported to date in 2015, compared with a total of six cases reported during 2014. Onset of paralysis in the latest reported WPV type 1 (WPV1) case was July 24, 2014. Only one case of circulating vaccine-derived poliovirus type 2 (cVDPV2) has been reported to date in 2015, compared with 20 cVDPV2 cases during the same period in 2014. Pending final laboratory testing of 218 remaining specimens of 16,617 specimens collected since January 2015, Nigeria could be removed from the WHO list of polio-endemic countries in September 2015. Major remaining challenges to the national polio eradication program include sustaining political support and program funding in the absence of active WPV transmission, maintaining high levels of population immunity in hard-to-reach areas, and accessing children in security-compromised areas of the northeastern states.

Threats to polio eradication in high-conflict areas in Pakistan and Nigeria: a polling study of caregivers of children younger than 5 years

Elimination of poliovirus from endemic countries is a crucial step in eradication; however, vaccination programmes in these areas face challenges, especially in regions with conflict. We analysed interviews with caregivers of children living in two polio-endemic countries to assess whether these challenges are largely operational or also driven by resistance or misinformation in the community. We designed and analysed polls based on face-to-face interviews of a random sample of parents and other caregivers of children younger than 5 years in regions of Pakistan and Nigeria at high risk for polio transmission. In both countries, the sample was drawn via a stratified multistage cluster design with random route household selection. The questionnaire covered awareness, knowledge, and attitudes about polio and oral polio vaccine (OPV), trust in vaccination efforts, and caregiver priorities for government action. We assessed experiences of caregivers in accessible higher-conflict areas and compared their knowledge and attitudes with those in lower-conflict areas. Differences were tested with two-sample t tests. The poll consisted of 3396 caregivers from Pakistan and 2629 from Nigeria. About a third of caregivers who responded in higher-conflict areas of Pakistan (Federally Administered Tribal Areas [FATA], 30%) and Nigeria (Borno, 33%) were unable to confirm that their child was vaccinated in the previous campaign. In FATA, 12% of caregivers reported that they were unaware of polio, and in Borno 12% of caregivers reported that vaccinators visited but their child did not receive the vaccine or they did not know whether the child was vaccinated. Additionally, caregivers in higher-conflict areas are less likely to hold beliefs about OPV that could motivate acceptance and are more likely to hold concerns than are caregivers in lower-conflict areas. Beyond the difficulties in reaching homes with OPV, challenges for vaccination programmes in higher-conflict areas extend to limited awareness, negative attitudes, and gaps in trust. Vaccination efforts might need to address underlying attitudes of caregivers through direct communications and the selection and training of local vaccinators. Harvard T H Chan School of Public Health and UNICEF.

Environmental Surveillance for Poliovirus in Polio High Risk States of Nigeria, 2011- 2012

Introduction: Nigeria is one of the three polio endemic countries in the world along Pakistan and Afghanistan. The detection of persons with Acute Flaccid Paralysis (AFP) and testing of stool specimens from these patients is the surveillance standard for detection of poliovirus. World Health Organization recommends complementary surveillance by testing sewage samples and stool of healthy children. Kano is the epi-center of polio in Nigeria. Environmental surveillance was introduced in June 2011 in Kano State and in April 2012 in Sokoto State. Methods: Grab method was used to collect sewage samples by trained environmental health workers. The samples were tested in Ibadan Polio Laboratory which is part of the Global Polio Laboratory Network. The Samples were concentrated using the two-phase separation method. Isolation of Poliovirus was carried out in RD and L20B cell lines. Poliovirus identification was done using the micro neutralization techniques. Results: In Kano State, from week 28 of 2011 to week 52 of 2012, a total of 60 samples were collected. In Sokoto State, from week 13 – 52 of 2012, a total of 80 sewage samples were collected from four sewage sites. In Kano and Sokoto, 62 and 93 single or mixed isolates were detected from the samples. In Kano, 39 (63%) of the isolates were Sabin viruses, 16 (26%) were circulating vaccine derived polio viruses type 2 (cVDPV2), 2 (3%) were wild polio virus type 1 (WPV1), 4 (6%) were non polio enteroviruses (NPENT) and 1 (3%) were wild polio virus type 3 (WPV3). In Sokoto, 33 (35%) of the isolates were cVDPV2, 27 (29%) were Sabin viruses, 16 (17%) were wild virus type 1 and 17 (18%) were non polio enteroviruses. No wild virus type 3 was detected from AFP cases and environmental samples in Sokoto State in 2012. Conclusion: The results confirm the prevailing immunity gap in polio high risk areas of Nigeria and pronounced immunity gap against type 2 polio virus in Sokoto. Long distance travelers such as nomads play important role in disseminating poliovirus. Special focus should be given to reach and vaccinate such underserved and migrant communities. In addition to the national campaigns with bivalent oral polio vaccine (bOPV) and trivalent oral polio vaccine (tOPV), an aggressive strategy should be adopted to mop up any detection of cVDPV in cases, contacts, or the environment.

Quantifying the impact of expanded age group campaigns for polio eradication.

A priority of the Global Polio Eradication Initiative (GPEI) 2013–2018 strategic plan is to evaluate the potential impact on polio eradication resulting from expanding one or more Supplementary Immunization Activities (SIAs) to children beyond age five-years in polio endemic countries. It has been hypothesized that such expanded age group (EAG) campaigns could accelerate polio eradication by eliminating immunity gaps in older children that may have resulted from past periods of low vaccination coverage. Using an individual-based mathematical model, we quantified the impact of EAG campaigns in terms of probability of elimination, reduction in polio transmission and age stratified immunity levels. The model was specifically calibrated to seroprevalence data from a polio-endemic region: Zaria, Nigeria. We compared the impact of EAG campaigns, which depend only on age, to more targeted interventions which focus on reaching missed populations. We found that EAG campaigns would not significantly improve prospects for polio eradication; the probability of elimination increased by 8% (from 24% at baseline to 32%) when expanding three annual SIAs to 5–14 year old children and by 18% when expanding all six annual SIAs. In contrast, expanding only two of the annual SIAs to target hard-to-reach populations at modest vaccination coverage—representing less than one tenth of additional vaccinations required for the six SIA EAG scenario—increased the probability of elimination by 55%. Implementation of EAG campaigns in polio endemic regions would not improve prospects for eradication. In endemic areas, vaccination campaigns which do not target missed populations will not benefit polio eradication efforts.

Lot quality assurance sampling to monitor supplemental immunization activity quality: an essential tool for improving performance in polio endemic countries.

Monitoring the quality of supplementary immunization activities (SIAs) is a key tool for polio eradication. Regular monitoring data, however, are often unreliable, showing high coverage levels in virtually all areas, including those with ongoing virus circulation. To address this challenge, lot quality assurance sampling (LQAS) was introduced in 2009 as an additional tool to monitor SIA quality. Now used in 8 countries, LQAS provides a number of programmatic benefits: identifying areas of weak coverage quality with statistical reliability, differentiating areas of varying coverage with greater precision, and allowing for trend analysis of campaign quality. LQAS also accommodates changes to survey format, interpretation thresholds, evaluations of sample size, and data collection through mobile phones to improve timeliness of reporting and allow for visualization of campaign quality. LQAS becomes increasingly important to address remaining gaps in SIA quality and help focus resources on high-risk areas to prevent the continued transmission of wild poliovirus.

Update on polio eradication in the World Health Organization South-East Asia Region, 2013.

There has been a tremendous amount of progress toward polio eradication in the World Health Organization South-East Asia Region particularly over the past 4 years. In 1988, there were >25,000 reported cases of wild poliovirus infection in the South-East Asia Region, and because of substantial underreporting the estimated polio burden was probably 10-fold higher. Following the initiation of mass polio immunization campaigns in the mid-1990s and years of intense effort, the 11 countries of the South-East Asia Region reported no cases of wild poliovirus infection in 2012. With India reporting the last wild poliovirus case in the region, on 13 January 2011, and its subsequent removal from the list of polio-endemic countries, in February 2012, the South-East Asia Region is firmly on track for polio-free certification in early 2014.

Strengthening the partnership between routine immunization and the global polio eradication initiative to achieve eradication and assure sustainability.

Since the launch of the Global Polio Eradication Initiative (GPEI) in 1988, the number of polio endemic countries has declined from 125 to 3 in 2013. Despite this remarkable achievement, ongoing circulation of wild poliovirus in polio-endemic countries and the increase in the number of circulating vaccine-derived poliovirus cases, especially those caused by type 2, is a cause for concern. The Polio Eradication and Endgame Strategic Plan 2013-2018 (PEESP) was developed and includes 4 objectives: detection and interruption of poliovirus transmission, containment and certification, legacy planning, and a renewed emphasis on strengthening routine immunization (RI) programs. This is critical for the phased withdrawal of oral poliovirus vaccine, beginning with the type 2 component, and the introduction of a single dose of inactivated polio vaccine into RI programs. This objective has inspired renewed consideration of how the GPEI and RI programs can mutually benefit one another, how the infrastructure from the GPEI can be used to strengthen RI, and how a strengthened RI can facilitate polio eradication. The PEESP is the first GPEI strategic plan that places strong and clear emphasis on the necessity of improving RI to achieve and sustain global polio eradication.

Polio outbreak investigation and response in Somalia, 2013.

For >2 decades, conflicts and recurrent natural disasters have maintained Somalia in a chronic humanitarian crisis. For nearly 5 years, 1 million children <10 years have not had access to lifesaving health services, including vaccination, resulting in the accumulation by 2012 of the largest geographically concentrated cohort of unvaccinated children in the world. This article reviews the epidemiology, risk, and program response to what is now known as the 2013 wild poliovirus (WPV) outbreak in Somalia and highlights the challenges that the program will face in making Somalia free of polio once again. A case of acute flaccid paralysis (AFP) was defined as a child <15 years of age with sudden onset of fever and paralysis. Polio cases were defined as AFP cases with stool specimens positive for WPV. From 9 May to 31 December 2013, 189 cases of WPV type 1 (WPV1) were reported from 46 districts of Somalia; 42% were from Banadir region (Mogadishu), 60% were males, and 93% were <5 years of age. All Somalian polio cases belonged to cluster N5A, which is known to have been circulating in northern Nigeria since 2011. In response to the outbreak, 8 supplementary immunization activities were conducted with oral polio vaccine (OPV; trivalent OPV was used initially, followed subsequently by bivalent OPV) targeting various age groups, including children aged <5 years, children aged <10 years, and individuals of any age. The current polio outbreak erupted after a polio-free period of >6 years (the last case was reported in March 2007). Somalia interrupted indigenous WPV transmission in 2002, was removed from the list of polio-endemic countries a year later, and has since demonstrated its ability to control polio outbreaks resulting from importation. This outbreak reiterates that the threat of large polio outbreaks resulting from WPV importation will remain constant unless polio transmission is interrupted in the remaining polio-endemic countries.

Progress toward global interruption of wild poliovirus transmission, 2010-2013, and tackling the challenges to complete eradication.

Despite substantial progress, global polio eradication has remained elusive. Indigenous wild poliovirus (WPV) transmission in 4 endemic countries (Afghanistan, India, Nigeria, and Pakistan) persisted into 2010 and outbreaks from imported WPV continued. By 2013, most outbreaks in the interim were promptly controlled. The number of polio-affected districts globally has declined by 74% (from 481 in 2009 to 126 in 2013), including a 79% decrease in the number of affected districts in endemic countries (from 304 to 63). India is now polio-free. The challenges to success in the remaining polio-endemic countries include (1) threats to the security of vaccinators in each country and a ban on polio vaccination in areas of Afghanistan and Pakistan; (2) a risk of decreased government commitment; and (3) remaining surveillance gaps. Coordinated efforts under the International Health Regulations and efforts to mitigate the challenges provide a clear opportunity to soon secure global eradication.

Global health and U.S. health--inextricably linked.

There have been many triumphs in public health during the last half-century; however, none have been more significant than the advancements in vaccines that have contributed to a dramatic decline in child mortality and infectious disease in the United States and many other parts of the world. As recently as 1967, an estimated 2 million people were dying each year from smallpox. With the development of an effective vaccine and worldwide immunization campaign, the disease was eradicated by 1980. A quarter-century ago, polio was endemic in 125 countries and paralyzing an estimated 350,000 children every year. In 2013, there were just three polio-endemic countries (i.e., countries that have never terminated indigenous poliovirus transmission) remaining—Nigeria, Pakistan, and Afghanistan—and 400 reported cases.1 In the U.S., vaccine-preventable diseases (VPDs) are at or near record lows,2 thanks to new or improved vaccines and immunization systems that protect children against 16 diseases.3,4 In the U.S., our commitment to immunizations is also an investment in our children. A recent study estimated that vaccination of each U.S. birth cohort with the recommended childhood immunizations prevents 42,000 deaths and 20 million cases of disease over the lifetime of the cohort, with a net savings of about $13.5 billion in direct costs and nearly $69 billion in direct and indirect societal costs.5 It is hard to argue with such numbers. Yet, worldwide, VPDs still account for one of every five deaths among children younger than 5 years of age.6 That burden falls most heavily on poor countries, but the potential spread of infectious diseases poses a significant public health threat to people in all 50 states and the District of Columbia. For example, although the number of polio cases worldwide remains near the record low, reported wild poliovirus cases in countries that had previously eliminated polio increased from six cases in 2012 to 256 cases in 2013. The increase is largely attributable to the difficulty of reaching children in areas of conflict and civil war.7 In the U.S. in 2013, there was a significant spike in measles cases, due almost entirely to people who brought the infection home after traveling overseas.8 Both examples are reminders that infectious diseases can strike people anywhere, and that U.S. health is inextricably linked to global health.

Epidemiological Characteristics of Poliomyelitis during the 21st century (2000-2013)

&lt;p&gt;Poliovirus is the pathogenic agent of paralytic poliomyelitis that belongs to the picornaviridae family. Poliomyelitis has an extended history dating over to the Egyptian eighteenth dynasty. It was recognized as distinct disease in the late nineteenth century when the world was ravaged by large number of outbreaks and epidemics in many countries. Paralytic Polio, the rarest but the most severe form of the disease, is characterized by acute flaccid paralysis of any or rarely both of the limbs. Increasing epidemics during the late 19&lt;sup&gt;th&lt;/sup&gt; and 20&lt;sup&gt;th&lt;/sup&gt; centuries lead to the initiation of a worldwide global effort for polio eradication in 1988, super headed by WHO and various other organizations. The launch of Global Polio Eradication Initiative together with the introduction of two polio vaccines resulted in 99% reduction of wild poliovirus cases worldwide while the total number of polio-endemic countries dropped from 24 countries in the year 2000 to only three countries in 2012; Afghanistan, Nigeria and Pakistan. This review will focus on the general biology of poliovirus, some historic and geographic epidemiological aspects of poliomyelitis eradication during the year 2000-2012 and also on the major failing factors associated with the efficiency of the vaccines to eradicate polio in Pakistan.&lt;/p&gt;