What is Polio

• Polio [PO-lee-oh] is a viral disease that can damage the nervous system and cause paralysis.
• The polio virus enters the body through the mouth, usually from hands contaminated with the faeces (pooh) of an infected person.
• Polio is preventable by immunisation.
• Since polio immunisation has become widespread in the developed world, cases of polio are rare. However, polio remains a problem in many parts of the world.

What is polio?

Polio, short for poliomyelitis, is a disease that can damage the nervous system and cause paralysis. Since polio immunisation has become widespread in the developed world, cases of polio are rare. However, polio remains a problem in many parts of the world.

What is the infectious agent that causes polio?

Polio is caused by any of three polio viruses.

Where is polio found?

Before the availability of polio immunisation, polio was common worldwide. However, with strong immunisation programs and efforts by organisations such as the World Health Organisation (WHO) and Rotary International to rid the world of polio, circulation of polio viruses is limited to a decreasing number of countries. The greatest risk is now in the Indian subcontinent and, to a lesser extent, in West and Central Africa.

How do people get polio?

The polio virus lives in the throat and intestinal tract of infected persons. The virus enters the body through the mouth, usually from hands contaminated with the faeces (pooh) of an infected person. Objects, such as eating utensils, can also spread the virus. Food and water are not thought to play a major role in the spread of polio.

What are the signs and symptoms of polio?

The polio virus attacks the nerve cells that control muscle movements. Many people infected with the virus have few or no symptoms. Others have short-term symptoms, such as headache, tiredness, fever, stiff neck and back, and muscle pain.

More serious problems happen when the virus invades nerves in the brain and causes paralysis of the muscles used in swallowing and breathing. Invasion of the nerves in the spinal cord can cause paralysis of the arms, legs, or trunk.

How soon after exposure do symptoms appear?

Symptoms usually start 7 to 14 days after exposure to the virus. Infected persons are most contagious from a few days before to a few days after the start of symptoms. However, persons with polio can spread the infection for as long as the virus is in their throat or faeces. The virus can be found in the throat for about 1 week after infection and in the faeces for 6 weeks or longer.

How is polio diagnosed?

Polio is diagnosed by a blood test or culture.

Who is at risk for polio?

Polio is most common in infants and young children, but complications occur most often in older persons.

What complications can result from polio?

Complications include paralysis, most commonly of the legs. Paralysis of the muscles that control breathing and swallowing can be fatal.

In very rare cases, the oral vaccine used to prevent polio can cause polio paralysis in persons who are vaccinated (1 in every 8.1 million doses) and in people who are close contacts of a vaccinated person (1 in every 5 million doses). About 8 to 9 cases of paralytic polio caused by the oral vaccine have been reported in the United States yearly.

What is the treatment for polio?

There is no treatment for polio. A polio patient must receive expert medical care, especially at the beginning of the illness.

How common is polio?

The last case of natural polio infection in the UK was in 1982.

Since then all cases of natural infection have been imported from parts of the world where the disease still exists.

The last case of polio to be imported from overseas occurred in 1993.

However, thousands of polo infections still occur in other parts of the world. Most cases are reported from Asia and Africa.

How can polio be prevented?

Two types of polio vaccine are available: oral polio vaccine (OPV) and inactivated polio vaccine (IPV).