Polio, or poliomyelitis, is a disabling and life-threatening disease caused by the poliovirus. The virus spreads from person to person and can infect a person's spinal cord, causing paralysis (can't move parts of the body). Polio is caused by 1 of 3 types of the poliovirus. It often spreads due to contact with infected feces. This often happens from poor handwashing. It can also happen from eating or drinking contaminated food or water.