Poliovirus
Polio paralysis is caused by a human enterovirus called the wild poliovirus. It can interact in its host in two ways:
- Infection not including the central nervous system, which causes a minor illness with mild symptoms
- Infection including the central nervous system, which may cause paralysis
Less than 1% of wild poliovirus infections result in paralysis. The virus is most often spread by the faecal-oral route. It enters through the mouth and multiplies in the intestine. Infected individuals shed poliovirus into the environment for several weeks, where it can spread rapidly through a community, especially in areas of poor sanitation.
There are two forms of poliovirus:
