Fact sheet No 114: Poliomyelitis - Revised April 2001 (WHO, 2001, 4 p.)

Revised April 2001

Poliomyelitis and its symptoms: Poliomyelitis (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 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. One in 200 infections leads to irreversible paralysis (usually in the legs). Amongst the paralysed patients, 5%-10% die when their breathing muscles become immobilized.

Persons at risk of polio: Polio mainly affects children under three years of age.

Prevention of polio: As there is no cure for polio, the best treatment is preventive. A few drops of a powerful vaccine, given multiple times, will protect a child for life.

Polio caseload: In 2000, there were fewer than 3500 reported polio cases worldwide. Tens of thousands more children are infected with the virus; while they do not suffer paralysis, they can infect other children.

The Global Polio Eradication Initiative

Launch: In 1988, the Forty-first World Health Assembly, consisting then of delegates from 166 Member States, launched a global initiative to eradicate polio by the end of the year 2000. This followed the successful eradication of smallpox in 1979 and progress during the 1980s towards elimination of the poliovirus in the Americas, as well as Rotary International's commitment to raise funds for polio eradication. The eradication of polio should be certified in 2005.

Progress: In the 13 years since the Global Polio Eradication Initiative was launched, the number of cases has fallen by 99% from an estimated 350 000 cases. At the end of 2000, the number of polio-infected countries was no more than 20, having fallen from 125.

In 1994, the World Health Organization (WHO) Region of the Americas was certified polio-free. In 2000, the WHO Western Pacific Region (which includes China) was certified polio-free, and the WHO European Region has been free of polio for over two years. Widely endemic on five continents in 1988, polio is now concentrated only in parts of sub-Saharan Africa and the Indian sub-continent.

Strategies: The eradication of polio requires a programme of work ranging from massive immunization activities to aggressive laboratory containment of poliovirus stocks. In order to realize the full humanitarian and economic benefits of polio eradication, the programme also extends to international consensus-building around future immunization policy.

There are five main activities necessary to realize polio's eradication, the global certification target of 2005, and eventual cessation of polio immunization:

· Conduct effective and high-quality national immunization days (NIDs) and mop-up campaigns to interrupt wild poliovirus transmission

· Develop and sustain certification-standard surveillance and laboratory systems that can rapidly identify polio-infected areas

· Ensure laboratory containment of wild poliovirus stocks

· Develop a consensus strategy to stop polio immunization after certification of eradication

· Use polio eradication to strengthen and expand routine immunization services

The target date for certification of the world as polio-free is 2005.

Coalition The Global Polio Eradication Initiative is spearheaded by WHO, Rotary International, the U.S. Centers for Disease Control and Prevention (CDC) and the United Nations Children's Fund (UNICEF).

This coalition also includes national governments; private foundations (e.g. United Nations Foundation, Bill & Melinda Gates Foundation); development banks (e.g. World Bank); donor governments (e.g. Australia, Austria, Belgium, Canada, Denmark, Finland, Germany, Ireland, Italy, Japan, the Netherlands, Norway, Portugal, United Kingdom and United States of America); humanitarian organizations (e.g. the International Red Cross and Red Crescent movement) and corporate partners (e.g. Aventis Pasteur, De Beers). Volunteers in developing countries also play a key role: ten million have participated in mass immunization campaigns.

Countries at Risk of Polio

As long as a single child remains infected with poliovirus, children in all countries are at risk of contracting the disease. The poliovirus can be easily reimported into a country and can spread rapidly. At the beginning of 2001, up to 20 countries still had ongoing poliovirus transmission (reduced from 30 countries at the beginning of 2000).

There are ten highest priority countries and they fall into two categories:

· 'Poliovirus reservoirs' where transmission is particularly intense. These countries are characterized by large populations with low routine immunization coverage and poor sanitation. They are Bangladesh, Ethiopia, India, Nigeria and Pakistan.

· Countries affected by conflict, where implementation of vaccination and surveillance activities is particularly challenging. They are Afghanistan, Angola, the Democratic Republic of the Congo, Somalia and Sudan.

Challenges Faced in Polio Eradication

Polio eradication faces three main challenges:

Access: Securing access to all children, especially those in conflict-affected countries, is crucial. The success in establishing access, cease-fires and "Days of Tranquillity" for countries such as Afghanistan and the Democratic Republic of the Congo demonstrates the feasibility of working successfully in conflict-affected areas. These efforts must be expanded, drawing upon the strengths of the United Nations Secretary-General's office, many UN agencies, the International Red Cross and Red Crescent movement, and other new and existing partners.

Funding: Necessary financial resources must be secured to purchase oral polio vaccine (OPV), plan and implement national immunization days and mop-up campaigns, and cover surveillance and laboratory costs. The total external financial support needed to the end of 2005 – the target date for certification – is US$ 1 billion. The funding gap is US$ 400 million. A failure to interrupt transmission in time for polio-free certification in 2005 will increase the cost of the programme by an estimated US$ 100 million for every year the programme runs beyond the deadline.

Political commitment: Sustaining political commitment from the highest levels of government is particularly challenging in the face of a disappearing disease. In polio- endemic countries, personal monitoring by the head of state of the progress towards eradication is key to improving the quality of activities. In polio-free countries, political commitment is needed for sustaining certification-standard surveillance and achieving laboratory containment of poliovirus.

In addition, priority reservoir countries require a special effort, including extra national immunization days and house-to-house mop-up campaigns. Certification-standard surveillance is needed to find the last cases in every country and evaluate the status for certification.

Once polio is eradicated, the laboratories of the world will be the only remaining location of the virus. As an increasing number of countries become polio-free, the virus needs to be safely and securely stored in laboratories to ensure no inadvertent release occurs after eradication.

Impact of the Global Polio Eradication Initiative

Since the global initiative began in 1988, Rotary International estimates that three million people in the developing world, who would have been paralysed, are walking because they have been immunized against polio. Nearly two billion children worldwide have been immunized during national immunization days in the last five years. In 2000, 550 million children were reached as part of these efforts.

Tens of thousands of public health workers have been trained to investigate cases of paralysis and manage immunization programmes.

On average, one out of 250 people in a country are involved in polio immunization campaigns. Tens of millions of volunteers have been trained to deliver OPV and vitamin A.

In 2000, over 50 countries gave vitamin A during polio national immunization days, preventing over 240 000 childhood deaths.

Cold chain, transport and communications systems for immunization have been strengthened.

A polio laboratory network of 148 polio laboratories has been established.

Future Benefits of Polio Eradication

The savings of polio eradication, once immunization stops, are estimated to be US$ 1.5 billion per year – funds that can be used to address other public health priorities.

In many countries polio eradication is expanding the capacity to tackle other diseases by building effective disease reporting and surveillance systems, training epidemiologists and establishing a global laboratory network.

No child, regardless of race, sex, ethnicity, economic status or religious belief, need ever fear or suffer from this crippling disease.

For further information, journalists can contact the Spokesperson's Office, WHO. Geneva. Telephone: (+41 22) 791 2599. Fax: (+41 22) 791 4858. E-mail: inf@who.int. All WHO Press Releases, Fact Sheets and Features as well as other information on this subject can be obtained on Internet on the WHO home page https://www.who.int or visit https://www.polioeradication.org.

© WHO/OMS, 1998