Polio (or poliomyelitis) is a disease caused by poliovirus. It can cause lifelong paralysis (cannot move parts of the body), and it can be deadly.

Most people who get infected with poliovirus (about 72 out of 100) will not have any visible symptoms. Some people will have flu-like symptoms that can include:

Sore throat
Fever
Fatigue (tiredness)
Headache
Nausea
Vomiting
Stomach pain

These symptoms usually last 2 to 5 days, then go away on their own.

Rarely, people with poliovirus infection will develop more serious symptoms that affect the brain and spinal cord, like paresthesia (feeling of pins and needles in the legs), meningitis (infection of the covering of the spinal cord and/or brain), or paralysis (can’t move parts of the body) or weakness in the arms, legs, or both.

People who never received or completed the polio vaccine series are most at risk of contracting and getting sick from poliovirus. The risk of severe disease and death after poliovirus infection in an unvaccinated person increases with increasing age.

Poliovirus is very contagious and spreads through person-to-person contact. It spreads through contact with the stool (poop) of an infected person or droplets from a sneeze or cough. If you get stool or droplets from an infected person on your hands and you touch your mouth, you can get infected. Also, if your child puts objects, like toys, that have stool or droplets on them into their mouth, they can get infected.

An infected person may spread the virus to others immediately before and usually 1 to 2 weeks after developing symptoms. The virus may live in an infected person’s intestines for many weeks. They can contaminate food and water when they touch it with unwashed hands.