Weinstein L. Poliomyelitis. Harrisons's Principles of Internal Medicine, 7th edn. McGraw Hill, New York, 1974. Disease Profile Poliomyelitis is caused by a highly infectious enterovirus whose only known host is man. By the time a first case is recognised in a family, all seronegative family members have probably been infected due to the rapidity of viral dissemination.
Viral spread is enhanced by crowding and poor sanitation.
Disease course Poliovirus enters the body via the mouth and then replicates in the pharynx and gastrointestinal tract of the host. The incubation period of the disease is typically around 1 week and the disease course varies according to severity. The response to poliovirus infection is highly variable and is classified according to the severity of the clinical presentation. In the majority of cases the disease produces only mild illness characterised by fever, sore throat and nausea, which resolves within a few days. Around one-third of cases that reach this stage resolve within 7 days but the remaining cases progress to paralysis.