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The virus.

Polio or poliomyelitis (also know as infantile paralysis) is a viral infection caused by polio enterovirus type 1, 2 or 3. It affects primarily young children and is mostly spread by person-to-person contact through the faecal-oral route. After infection, the virus multiplies in the gut for about two weeks. The vast majority of patients show no symptoms or have flu-like symptoms. They can however unknowingly infect other people. For every person with paralysis another 200 or more may be infected but show no outward sign.
Isolation of virus in the stool can prove that the patient has a polio infection.


Most infections are mild with symptoms like nausea, fever, sore throat or headache.
Sometimes (1 to 2 %) encephalitis may occur.
Only about 1% gets partial or complete paralysis. The virus then has spread to the central nervous system, primarily the spinal cord.
The virus replicates in the nervous system and may cause significant neuronal loss.
Motor neurons that are destroyed can no longer send impulses to muscles and that means paralysis.
Sometimes the virus affects the brainstem, causing symptoms like breathing-, swallowing- or other vital problems. This is known as bulbar polio.
Some people die as a result from the infection.


After the acute infection survivors can be left with various degrees of weakness, paralysis, orthopaedic problems, fatigue, pain, problems with breathing or swallowing. Others seem to have made a full recovery.


Prevention is the only cure for poliomyelitis. This can be done with inactivated polio vaccine (IPV) or oral polio vaccine (OPV).


In Europe and other parts of the world there were frequent big epidemics in the first half of the former century until vaccination started in the mid 1950s.
It is estimated that in Europe around 700.000 people are now living with the effects of this dreaded disease.
Although Europe is declared polio-free, thanks to the effort of the WHO and partners, there is still the danger of somebody bringing it into Europe as long as the world is not polio-free.
Immunisation still is necessary.



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