Polio & Post Polio
Some common questions about Polio
What is polio?
Polio is an infectious disease caused by one of three polioviruses.
How is the virus spread?
The virus is spread by person-to-person contact with infected secretions from the nose or mouth, or via infected faeces. After initial infection the virus is shed intermittently in faeces (excrement) for several weeks. During that time, polio can spread rapidly through communities.
What happens when the virus enters the body?
When the virus enters the body it multiplies in the throat and intestines. It can then invade the central nervous system, destroying or damaging the nerve cells (motor neurons) that control muscle movement. This can lead to muscle paralysis, affecting any part of the body, or death.
What are the symptoms?
Polio infection may be mild, causing few symptoms. 95% of people have minor flu-like symptoms, such as nausea, vomiting, fever, sore throat and headache. People may not always realise they have polio. In around 5% of people, the virus gets into their central nervous system. For most, this will cause symptoms similar to meningitis (inflammation of the lining around the brain and spinal cord) or encephalitis (inflammation of the brain tissue) with high fever, stiff neck, back and muscle pain, and headache. This is known as non-paralytic polio.Paralysis results in around 1 – 2% of people. This is where the poliovirus invades the motor neurons (nerves controlling movement) causing weakness, paralysis, muscle cramps and muscle pain. This is known as paralytic polio. Sometimes the poliovirus affects the brain stem, causing symptoms like breathing, swallowing or cardiovascular problems and facial weakness. This is known as bulbar polio.
What are the effects of polio?
People may be left with varying degrees of weakness, paralysis, fatigue, muscle pain, breathing or orthopaedic problems. Others have limited paralysis or appear to have made a full recovery. Polio can result in permanent disability, and can kill.
Did you know?
Polio cases have decreased by over 99% since 1988, from an estimated more than 350,000 cases globally to 1,912 reported cases as of 16 January 2007. This reduction is the result of the global effort to eradicate the disease. It is estimated that there are120,000 people living in the UK who have had polio.There are now no new cases of polio in the UK due to continuing polio vaccination.
Can polio be prevented?
Polio can be prevented by vaccination.
Do vaccinations really make a difference?
Yes they do. Since the programme was introduced into the UK in the early 1960s notifications of polio have dropped from over 6,000 in 1955 to nil today.The risk of polio infection has been eliminated in most, but not all countries.However, the poliovirus could be imported into a polio-free country with the risk of it spreading rapidly amongst non-immunised people.Since October 2004, people in the UK have been vaccinated using an inactivated polio vaccine (IPV) given by injection into a muscle. This replaced the routine use of oral polio vaccine in the UK.The IPV vaccine uses inactive (not live) poliovirus and does not cause polio. Polio vaccine, given multiple times as per advice, almost always protects for life.
Everyone should ensure that they are protected against polio before travel to countries considered a risk for polio. You are advised to seek specialist travel health advice on this - your GP or practice nurse may be helpful. If you have had polio, but have not been vaccinated, you may not have immunity against all of the polioviruses and may need polio vaccination, especially if you are travelling to "at risk" countries. Do seek advice from your health care practitioner