What can be done to prevent the infection?

Polio can be almost completely prevented with polio immunization. There are still many parts of the world that are not vaccinated. The majority of cases occur in Indian, Asia, and Africa. Once everyone in the world has been vaccinated, people will not need to be immunized because the virus will die out. Routine vaccination is not recommended after a person is 18 years old.

What are the long-term effects of the infection?

The long-term effects of the disease include death, paralysis, and postpolio syndrome. In the past, when the muscles of the lungs were affected, polio almost always led to death. Nowadays less than 5% of persons with polio will die because the respiratory problems can be managed better. Only 1% to 2% of persons infected with polio get symptoms related to nerve damage. The rest of the people will get no symptoms or a minor flu-like illness.

After some years, the overburdened nerve cells can sometimes weaken and fail. This results in new muscle weakness, called postpolio syndrome. About half the people with polio will get postpolio syndrome.

What are the risks to others?

Polio is very contagious. The virus is spread directly from the stool of an infected person to the mouth of a noninfected person. This is usually from contaminated hands or eating utensils.