Acute infectious viral disease that can cause flaccid paralysis of muscles. Severe epidemics killed or paralyzed many people, mostly children and young adults, until the 1960s, when Jonas Salk's injectable killed vaccine and Albert B. Sabin's oral attenuated live vaccine controlled polio in the developed world. Flulike symptoms with diarrhea may progress to back and limb pain, muscle tenderness, and stiff neck. Destruction of spinal cord motor cells causes paralysis, ranging from transient weakness to complete, permanent paralysis, in fewer than 20percnt of patients. Patients may lose the ability to use their limbs, to breathe, or to swallow and speak. They may need physical medicine and rehabilitation, mechanical breathing assistance, or tracheal suction to remove secretions. A “postpolio syndrome” occurs decades later in some cases, with weakness of muscles that had recovered.
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