Polio is a disease caused by a virus that affects the nervous system and is mainly spread by person-to-person contact. Polio can also be spread by drinking water or other drinks or eating raw or undercooked food that are contaminated with the feces of an infected person.Most people with polio do not feel sick.Some people have only minor symptoms, such as fever, tiredness, nausea, headache, nasal congestion, sore throat, cough, stiffness in the neck and back, and pain in the arms and legs. Most people recover completely.ost people with polio do not feel sick. Some people have only minor symptoms, such as fever, tiredness, nausea, headache, nasal congestion, sore throat, cough, stiffness in the neck and back, and pain in the arms and legs. Most people recover completely.