‘What further spread). The virus enters the bloodstream

‘What is the Biggest Limiting Factor in the Eradication of Poliomyelitis?’ Achele AgadaAbstract:Poliomyelitis is a viral disease which is associated with paralysis and limb disfigurement. ‘In 1952, poliomyelitis (‘polio’) reached a peak in the United States with over 21,000 paralytic cases.’This stemmed the invention of the inactivated polio vaccine (‘IPV) in 1955 by Jonas Salk, which was shortly replaced by the oral polio vaccine (‘OPV’) invented by Albert Sabin in the 1960’s. These vaccinations allowed formation of the ‘Global Polio Eradication Initiative (GPEI), where US$8billion was invested and 2.5 billion children immunised, with the help of 20 million volunteers, driven by the massive worldwide aim to eradicate polio by 2000. This aim ultimately was not met. Despite a 99% decrease in cases from 1988 to 2011, as of 2012, polio remains in three countries: Pakistan, Afghanistan and Nigeria – all considered developing countries (LEDC’s). This essay explores the biggest limiting factors in the eradication of poliomyelitis, with a focus on Nigeria, and how the continued prominence of the poliovirus could become a prominent issue for the Western world – despite being Polio free since 1991.Introduction:Poliomyelitis is an acute disease characterised by ‘flaccid asymmetric paralysis’ (a weakness in one or more limbs) and muscle atrophy. This is a result of small RNA viruses from the enterovirus group of the picornavirus family, which infect the human intestinal/digestive tract usually via fecal-oral route. There are three poliovirus serotypes (variations); P1, P2 and P3 and a major issue with this is that there is ‘minimal heterotypic immunity’, between the three stereotypes (immunity to one doesn’t provide immunity to another). Fortunately, the current IPV provides 99% immunity to all three serotypes after three doses.Pathogenesis (How the disease develops) and Clinical FeaturesOnce implanted the pharynx/gastrointestinal (‘GI’) tract, primary multiplication of the poliovirus occurs. The virus can be found in a carrier’s stool (which leads to further spread). The virus enters the bloodstream and local lymphoid tissue before infecting the nervous system. This leads to the characteristic manifestations of polio (paralysis, damage to spinal cord etc.) as the virus replicates and destroys cells in the anterior horn (spinal cord) and brainstem.The incubation period (time from exposure to symptoms) of non-paralytic poliomyelitis is 3-6 days but paralysis (from paralytic poliomyelitis) usually occurs after 7-21 days. Fewer than 1% of polio infection in children result in flaccid paralysis ( paralysis caused by infection)  and the death to case ratio is 2-5%. Initial Fight Against PolioBefore vaccinations were invented, Polio was killing up to half a million every year. After the invention of the IPV in 1955 by Jonas Salk polio transmission was halved in the US and even completely eliminated in some Scandinavian countries. The invention of the OPV in 1961 by Dr Albert Sabin, given in two doses to all children under 5, meant polio transmission was eradicated in the US by 1979. This was possible due to mass campaigns from 1963 using the OPV.The oral poliovirus vaccine contains live attenuated (reduced in virulence) poliovirus strains of all three serotypes. The polio vaccine strains establish an infection in the children they are administered to before replicating within the pharynx and intestine for 4-6 weeks. This time allows the vaccine recipient to establish humoral (body fluid controlled) and mucosal (takes place at mucosal membranes in the intestines, the urogenital tract and the respiratory system) immunity. One issue with the vaccine is that stable variants of the virus can mutate during replication and cause paralysis indistinguishable from poliomyelitis, if the mutated vaccine strains reach the central nervous system (CNS). This is known as ‘vaccine associated paralytic poliomyelitis’ (VAPP) and was estimated to be at 250-500 cases in 2002 by WHO – a global burden of 1 per 2-4 million births. This is a limitation to poliomyelitis eradication, as poorly researched and inaccurate sources of health information twist this information to suggest the vaccine is dangerous, causes polio and should not be administered. This slows down global efforts.As polio was eliminated in developed countries, mass campaigns to eliminate polio transmission spread through many developing countries such as Mexico and Cuba and developing countries quickly became the focus of the strategy to end polio. Rotary International, first became involved in polio eradication in 1979 by providing OPV to 6 million children in the Philippines. Their work with Dr Sabin, led to the Rotary’s ‘Polio Plus’ programme in 1985 aiming to immunise all children and pledging US$120million. Rotary International played a major role in the initial (and current) fight for polio eradication due to the funding they provided (now over US$600 million) which meant complete polio eradication was considered possible. WHO and UNICEF also began to tackle polio in 1985 with the ‘Universal Childhood Immunization Initiative’ which aimed to reduce child mortality by providing effective immunisation. In 1988, The World Health Assembly, were encouraged by the efforts and commitments of these groups and launched the global goal to eradicate polio by 2000. This goal was accepted in 1990 at the World Summit for Children, by WHO, UNICEF, partner organizations and heads of state and led to the ‘Global Polio Eradication InItiative’ which is the largest public global health initiative.A conventional ‘four pronged strategy’ was administered: high coverage of vaccination is administered with at least three doses of OPV; supplemental rounds of vaccination are provided, an effective method of acute flaccid paralysis (AFP) surveillance is established and finally house-to-house OPV campaigns must be carried out in the remaining areas where polio is still prevalent. This strategy was largely successful due to high level political advocacy (worldwide governments advocated vaccination) and mass mobilisation and incentives provided. Since, the initiative began polio endemic countries has decreased from 125 to three. In 1990, 80% childhood immunization coverage was achieved worldwide by the Universal Childhood Immunization Initiative, yet the 2000 global eradication goal was not met and even extended goal deadlines made by the GPEI have not been met.Of the three types of wild polioviruses (WPV not including VAPP), only type 1 is a major threat today. Type 2 was declared eradicated in 2015 and the last case of type 3 was seen in 2012. In 2013 the GPEI launched its most comprehensive initiative to completely eradicate the remaining 1% of polio cases. Issues with Polio Eradication in LEDC’s (Literature Review):Despite massive decreases of polio cases in Pakistan, Afghanistan and Nigeria, complete eradication in these countries has not occurred due to a number of issues. Primarily, the task of eradication in these countries is more challenging as they are developing countries with specific socio-economic pitfalls that make polio immunisation programmes more challenging. For example in Pakistan the polio eradication program which launched in 1994, resulted in a drop of polio cases from 1155 in 1997 to 28 in 2005. However, following drone attacks in FATA in 2007 (Federally Administered Tribal Areas) and the American war on terror in Pakistan, polio cases actually rose, reaching 306 in 2014. They have since dropped with reported cases in 2016 being 18, however this period of rising polio cases shows the damaging effects of violence and unrest to disease eradication. The main limiting factors to eradication in Pakistan are religious militancy, from groups such as Tehreek-e-Taliban (TTP) who distributed pamphlets against the polio vaccine due to a false belief that it contained Haram ingredients; increased Islamist insurgency and poor national security (driven by, fake polio campaigns used by the CIA such as the one to assassinate Osama Bin Laden, and drone attacks led by America to war on terror) in the form of attacks on polio workers and the local population. This culminated in the brutal killings of polio team workers in Pakistan to gain international media attention, which seriously derailed the eradication program. Other issues in Pakistan preventing polio eradication include poor routine immunisation, due to a lack of services, awareness and community interest, as well as, major misconceptions about the polio vaccine (such as infertility rumours spread by religious militants leading to over 40,000 parents refusing to vaccinate their children) a lack of communication between government and Pakistanis. The limiting factors in Afghanistan are much the same, with civil unrest in the war torn country being the biggest issue. Limited healthcare infrastructure, illiteracy and poverty are also issues preventing poliomyelitis eradication in Afghanistan, however a unique limitation to polio eradication in Afghanistan is frequent cross-border migration between Afghanistan and Pakistan which allows shared transmission. This Afghanistan to Pakistan migration has historically (since the Cold War era of 1960’s-1980’s) and still is largely, refugees trying to escape the ongoing wars. However, the more worrying (in terms of polio transmission) is the Pakistan to Afghanistan migration which results largely from Afghans returning to their home country – due to Pakistani authority hostility and persecution of Afghan refugees, as a result of ‘host country fatigue’. These difficult to solve issues are ultimately the reason poliomyelitis is still endemic in Pakistan, Afghanistan and Nigeria. Whilst these three countries are not isolated in the world in terms of poor socio-economic conditions, they are unique in that they have a complex combination of limiting factors which until recent have made eradication impossible. This is demonstrated in Nigeria which despite being one of the richest countries in Africa, with a GDP of over US$405 billion, it is the only remaining country in the continent to suffer from poliovirus. Nigeria: a Case Study In 2008, Nigeria had the greatest number of confirmed cases of poliomyelitis worldwide and in 2012, Nigeria was considered the global epicentre of poliovirus outbreaks with poliomyelitis cases doubling from 2011 to 2012. This was particularly strange considering poliomyelitis cases fell by 95% in 2010. One reason for this increase in polio cases is poor communication, which undermines vaccine delivery and increases vaccine hesitancy (a delay or refusal of vaccines). For example, increased polio campaigns within Nigeria were seen as suspicious to the population – an issue also seen in Pakistan when free provision of polio vaccine led to distrust in a country where healthcare is generally poor and expensive. Another possible factor preventing polio eradication in Nigeria could be the  massive size of the country and its 155 million population which means the usual issues of poverty, political and social volatility etc. are amplified. Carrying out a national polio vaccination scheme in Nigeria and Pakistan is much more challenging than in the UK which has a population of over 2x smaller than that of Nigeria. However, arguably population should not be a major factor, as Afghanistan has a considerably smaller population of around 35 million but has not eradicated polio and the USA’s mammoth population of over 323 million achieved polio eradication decades ago. Other factors must be making eradication in Nigeria particularly challenging. An alternate reason for the difficulty in polio eradication, is the diversity and divide of the country. Whilst roughly half the country is Muslim (predominantly in the North, where polio is a more pressing issue) and half is Christian, there are more than 250 ethnic groups within Nigeria. The harsh religious divide creates fierce political rivalry which has a major impact on the ability of the government to administer any national programmes in the long term. Similarly, the variability of local governments in terms of funding, organisation and priorities means that polio eradication is a large priority in some states but pushed aside in other states. In the two decades since the polio eradication programme was launched in Nigeria in 1996, Nigeria has faced a great many national issues which have slowed the eradication process. The brutal, and corrupt government led by General Sani Abacha for the two first years of the GPEI’s polio eradication scheme led to a general decreases in standard of living and a decline in all state run services. Over investment in the declining oil/petrol industry led to stagnation and massive economic decline. The poorer North saw a growing gap in terms of poverty and an amplification of the health crisis across Nigeria. On top of this corruption spread to the polio eradication programme, through General Abacha’s National Programme of Immunisation (NPI). All these issues only began the slow process of repair in 1998 following the General’s death, which allowed for the massive reduction in polio transmission in the 2000’s but progress oon turned to regression. Fear of polio vaccines is an issue in all three polio endemic countries however this issue was compounded in the Northern States of Nigeria due to multiple disastrous events regarding vaccines. The death of 11 children in the controversial Pfizer pharmaceuticals, meningitis drug trial in the majority Muslim deep Northern state of Kano,1996 (the same year the polio eradication scheme was launched) led to a massively vaccine suspicious Northern population. Direct polio vaccine hesitancy hit a high in the North in 2003 Nigeria’s Supreme Council for Shari’a (Islamic law) claimed: “there were strong reasons to believe that the polio immunisation vaccine was contaminated with antifertility drugs, contaminated with certain virus’ that cause HIV/AIDS and contaminated with Simian virus that are likely to cause cancers”. The drug was boycotted due to the backing of local and prominent Muslim groups and local governments, until eventually the governor of Kano suspended its administration leading to Kaduna, Bauchi and Zamarfa states to do the same. Parents lied about vaccination records, and polio vaccination in the north halted. This single event led a massive resurgence in polio cases, accounting for 80% of paralytic cases and costing US$500 million internationally. The boycott eventually ended in 2004 due to huge efforts by the GPEI to communicate with Muslim communities and authorities as well as the Northern governments. Eventually polio eradication campaigns won support of Nigeria which was demonstrated by the efforts of the Nigerian Olympic Committee to create ‘Polio-Free’ sporting ambassadors with hopes of national polio eradication by the 2012 olympics. This ultimately was not achieved. The biggest concerns in polio eradication in Nigeria today are worsening security and the threat of attacks by terrorist group the Boko Haram. Furthermore, the number of GPEI targets not met is causing a loss in hope which could further deter eradication efforts. Despite this Nigeria seems most likely out of the three remaining endemic countries to eradicate polio next. The last seen case of wild poliovirus in Nigeria was type 1 in August 2016 and so technically Nigeria has been free of wild poliomyelitis cases for over a year. However, this is not the first instance of temporary polio eradication (Nigeria appeared polio-free in 2015)and whilst poliomyelitis is still transmitted somewhere in the world it is a danger everywhere in the world – particularly in countries like Nigeria that have high susceptibility and a long history of the disease.Next Steps Towards Polio Eradication In all three endemic countries a ‘National Emergency Action Plan for Polio Eradication’ is in place which details how seriously the eradication programme is being taken. This is a crucial step for global eradication and helps improve the communication issues within the polio vaccination schemes. In Afghanistan, the latest plan involved ensuring all children in the country where vaccinated with OPV regardless of location, with a focus on those in high-risk areas (high risk of violence, poverty etc.as well as of polio transmission). Strategies are centered around slowing down transmission, through surveillance and larger intervention.  The same can be said of the Pakistani action plan, which has similar objectives of stopping poliovirus transmission in the reservoirs where it is the largest issue and increasing immunisation.The main aim in Nigeria, is to recover and strengthen the polio eradication programme following the reclassification as an endemic country in September 2016 following the previous year of no cases. This will involve, stronger involvement from authorities but general intensified social mobilisation on a national scale. Strategies for this involve: Creating an integrated message and overarching framework for eradication that will reach all levels;Reducing ‘ chronically missed children’ through investigations, surveys and tracking to ensure all children are vaccinated; Intense communication and more support for the northeast states where communication, specialist training and youth engagement is most needed;Ensuring high risk areas receive routine immunisation and that those working in these areas are kept accountable;Using international to state media, and government advocacy etc. to ensure strong political support for immunisation;Motivating front line workers with recognition and non-monetary rewards;Producing public documentation in the form of an annual polio communication report, monthly polio bulletin and analysis of progress made by the polio campaign.To ensure these strategies are implemented and objectives met, targets and goals have been set such as less than 2% of children in high risk areas being missed for vaccination. Whilst an integrated message, greater communication public documentation and government advocacy will help to raise vaccine hesitancy and improve the polio campaign in the country, the focus in Nigeria, unlike in Afghanistan and Pakistan, is very much on maintenance and ensuring consistency and dedication from the government, front line workers and general population – Nigeria are working on prevention whereas, Afghanistan and Pakistan are still working on the cure, this is likely due to the varying political climates. Nigeria has experience much more political unity than Afghanistan and Pakistan in recent years and so “there is hope for when the political situation improves” Living with the Effects of PoliomyelitisWhilst long term effects of smallpox disease are virtually non-existent, post-polio syndrome effects around 25-40% of polio survivors and hence the livelihood (quality of life) of hundreds of thousands worldwide. Post Polio Syndrome ConclusionRisks if Polio Eradication Does Not Occur According to Prof. David Salisbury, Director of immunisation at the Department of Health: “Polio remains a risk until the virus is gone from everywhere in the world”. This has been proven many times over with outbreaks of poliovirus in previously declared ‘poliomyelitis free’ countries. For example, from 2002-2005, 21 previously polio-free countries experienced a resurgence of wild-type polio. Whilst outbreaks of polio in countries with high routine immunity coverage and economic stability – such as that of China who suffered an outbreak of P1 poliomyelitis –  can be dealt with quickly in a matter of weeks and efficiently (43.7 million doses of OPV administered and US$26 million spent), similar outbreaks in poorer countries can be devastating. This was the case following the outbreak of P1 poliovirus in Syria in 2013, which led WHO to declare its first ‘global health emergency’. If Syria a country in which polio had previously been eradicated for 15 years could see a resurgence, it proved that more needed to be done. Interview FindingsWhat is the Biggest Limiting Factor?Disease eradication is not easy. Only smallpox has been eradicated before so the failed eradication of poliomyelitis does not reflect lack of effort but rather the difficulty for such a prevalent viral disease to be eradicated. The GPEI have tirelessly been working towards polio eradication worldwide and there is no doubt that this will be met. However certain factors have to be changed and these are not directly linked to polio administration. Peace must be achieved in war torn areas, better communication must be established and most importantly people must be educated. The biggest limiting factor in the eradication of poliomyelitis is not resources but rather vaccine hesitancy. No matter how much money is provided, if people refuse to take vaccines eradication can never be achieved. This issue is mirrored in the Western world when pseudoscience and fear mongering leads to vaccine refusal despite adequate resources and regular monitoring. When eradication is achieved, the GPEI still have a long way to go. Ensuring the disease stays gone means vaccination must continue. However, OPV cessation must be the focus moving forwards or vaccine-associated paralytic poliomyelitis will become the next terror. Certification of eradication must be awarded before celebrations can begin but even this cannot happen till it is ensured that the threat of future wild polio outbreaks is contained.Will polio be eradicated by 2018 in accordance to WHO’s target? The efforts to do so cannot be denigrated.Bibliography