Poliovirus infection case definition summary

Poliovirus is a single stranded RNA virus, a member of the family Picornaviridae, genus poliovirus. There are three strains poliovirus types 1-3. Poliovirus is an important cause of acute flaccid paralysis (AFP), which when attributable to poliovirus is known as paralytic poliomyelitis. Paralytic poliomyelitis follows approximately 0.1-2% of poliovirus infections and typically presents as an acute onset over 48hrs of progressive weakness and flaccidity of the extremities progressing to maximum severity within 1-10 days (1,2). Muscles of respiration and swallowing may be involved. There may be a febrile prodrome. Poliovirus infection is clinically inapparent in 90-95% of cases. Some 4-8% of infections present as abortive illness characterised by upper respiratory infection, gastroenteritis or influenza like illness, and a further 1-2% present as aseptic meningitis (1).