Poliomyelitis
27 February 2012
Key facts
- Polio (poliomyelitis) mainly affects children under five years of age.
- Approximately one in 200 infections leads to irreversible paralysis.
- Among those paralysed, 5% to 10% die when their breathing muscles become immobilized.
- Polio cases have decreased by over 99% since 1988, from an estimated 350 000 cases then, to 1 298 reported cases in 2011 (as of 20 feb 2012).
- The reduction is the result of the global effort to eradicate the disease.
- In 2012, only three countries (Afghanistan, Nigeria and Pakistan) remained polio-endemic, down from more than 125 in 1988.
- Still, as long as wild poliovirus circulates anywhere in the world, the risk of international spread persists and children (and even adults) in all countries are at risk of contracting the disease.
- In 2010-2011, 30 separate importations into previously polio-free countries occurred.
- In most countries, the global effort has expanded capacities to tackle other infectious diseases by building effective surveillance including laboratory systems and immunization systems.
- Success hinges on financing the next steps of the global eradication initiative.
Causes
- Polio is a highly infectious disease caused by a virus.
- It invades the nervous system, and can cause total paralysis in a matter of hours.
- The virus usually enters the body through the mouth and multiplies in the intestine.
- Initial symptoms are fever, fatigue, headache, vomiting, stiffness in the neck and pain in the limbs.
Prevention
- There is no cure for polio, but it can be prevented by immunization.
- Polio vaccine, given multiple times, can protect a person for life.
The Global Polio Eradication Initiative
Launch
- In 1988, the forty-first World Health Assembly, consisting then of delegates from 166 Member States, adopted a resolution for the worldwide eradication of polio.
- It marked the launch of the Global Polio Eradication Initiative, spearheaded by WHO, Rotary International, the US Centers for Disease Control and Prevention (CDC) and the United Nations Children’s Fund (UNICEF).
- This followed the certification of the eradication of smallpox in 1980, progress during the 1980s towards elimination of the poliovirus in the Americas, and Rotary International’s commitment to raise funds to protect all children from the disease.
Progress
- Overall, since the Global Polio Eradication Initiative was launched, the number of cases has fallen by over 99%.
- In early 2012, only three countries in the world remain polio-endemic. They are Afghanistan, Nigeria and Pakistan.
- Persistent pockets of polio transmission in northern Nigeria and in Afghanistan and Pakistan are key epidemiological challenges.
- In 1994, the WHO Region of the Americas (36 countries) was certified polio-free, followed by the Western Pacific Region (37 countries and areas, including China) in 2000 and the European Region (51 countries) in June 2002.
- In 2010, the European Region suffered its first importation of polio after certification, resulting in 475 cases in four countries. Twenty-nine people died.
- In 2011, the WHO Western Pacific Region also suffered an importation of wild poliovirus from Pakistan to China. Twenty-one persons got paralysed, of whom two died.
- The status of global polio eradication is quarterly reviewed by the Independent Monitoring Board (IMB) evaluating the progress towards each of the major milestones of the Global Polio Eradication Initiative Strategic Plan 2010-2012, determine the impact of any 'mid-course corrections' that are deemed necessary, and advise on additional measures when appropriate.
- Reviewing the latest global polio situation, on 21 January 2012, the WHO's Executive Board (EB) adopted a landmark resolution, declaring the completion of polio eradication a 'programmatic emergency for global public health'.
- In response to the EB's declaration of the completion of polio eradication a 'programmatic emergency for global public health', the Global Polio Eradication Initiative will implement a Polio Emergency Action Plan 2012-2013. The new Plan will establish an emergency approach, enhance management, accountability and performance monitoring and drive innovation to address systemic problems.
- The goals of the emergency in polio eradication are to:
- increase speed in identifying and addressing problems;
- better concentrate, coordinate and increase resources; and,
- strengthen accountability and monitoring mechanisms at all levels.
- Recognizing the risk polio continues to pose to polio-free countries area, the EB's 'programmatic emergency for global public health' outlines clear steps (polio-free) countries should take to minimise the risk and consequences of becoming re-infected:
- identify any areas with suboptimal immunization coverage and rapidly fill these gaps;
- strengthen surveillance to more rapidly detect a potential virus importation (allowing for a more rapid outbreak response); and,
- fully apply vaccination recommendations for all travellers to polio-infected areas.
Coalition
- The Global Polio Eradication Initiative (GPEI) is spearheaded by WHO, Rotary International, CDC and UNICEF. The eradication of polio is about equity in health and the moral imperative of reaching every child with an available health intervention.
Objectives
- The objectives of the Global Polio Eradication Initiative are:
- To interrupt transmission of wild poliovirus as soon as possible;
- To achieve certification of global polio eradication;
- To contribute to health systems development and strengthen routine immunization and surveillance for communicable diseases in a systematic way.
Strategies
- There are four core strategies to stop transmission of the wild poliovirus in areas that are affected by the disease or considered at high risk of re-infection:
- High infant immunization coverage with four doses of oral poliovirus vaccine (OPV) in the first year of life;
- Supplementary doses of OPV to all children under five years of age during supplementary immunization activities;
- Surveillance for wild poliovirus through reporting and laboratory testing of all acute flaccid paralysis (AFP) cases among children under 15 years of age;
- Targeted “mop-up” campaigns once wild poliovirus transmission is limited to a specific focal area.
Polio-free status
- Before a WHO region can be certified polio-free, three conditions must be satisfied:
- At least three years of zero polio cases due to wild poliovirus;
- Disease surveillance must meet international standards;
- The country must illustrate the capacity to detect, report and respond to “imported” polio cases.
- Equally important, once wild polioviruses are controlled in human populations, is to identify wild polioviruses in laboratories and ensure that they are stored under proper biosafety conditions (laboratory containment).