When are people with polio contagious?

Polio can spread from person to person through contact with the infected person's feces or saliva. People are most contagious during the first week of illness, but they can sometimes spread the virus for up to 3 weeks. The virus enters the body through the mouth and multiplies in the throat and intestines. It can then spread to the nervous system and cause paralysis.

People who are vaccinated against polio are protected from the disease, but they can still carry and spread the virus to others. This is why it is important for everyone to get vaccinated against polio, even if they live in an area where the disease is not common.