what causes polio

Polio is caused by infection with the poliovirus, which is a member of the genus Enterovirus. It is a highly infectious virus that primarily spreads from person to person via the fecal-oral route, such as through ingestion of contaminated food or water, or occasionally through oral-oral transmission via respiratory droplets. The virus infects the gastrointestinal tract and can spread to the nervous system, where it may cause paralysis. There are three serotypes of poliovirus, all capable of causing the disease symptoms. The virus attaches to cells in the throat and intestines, multiplies, then enters the bloodstream, and in some cases, invades the central nervous system leading to severe complications like paralysis.