Poliomyelitis

Poliomyelitis (commonly known as polio) is an acute infectious disease caused by the poliovirus, a human enterovirus belonging to the Picornaviridae family. The virus is transmitted primarily through the fecal-oral route and initially replicates in the oropharynx and gastrointestinal tract before potentially invading the central nervous system. While the majority of poliovirus infections are asymptomatic or cause only mild flu-like illness, in a small percentage of cases the virus destroys motor neurons in the spinal cord and brainstem, leading to acute flaccid paralysis. The disease predominantly affects the lower extremities, though any voluntary muscle group can be involved, including respiratory muscles, which can be life-threatening. Key clinical features of paralytic poliomyelitis include asymmetric acute flaccid paralysis, muscle weakness, loss of reflexes, and muscle atrophy. The disease can present in several forms: spinal poliomyelitis (affecting limb muscles), bulbar poliomyelitis (affecting cranial nerves and respiratory centers), or bulbospinal poliomyelitis (a combination of both). Initial symptoms often include fever, fatigue, headache, neck stiffness, and limb pain, followed by rapid onset of weakness. Decades after the acute infection, some survivors develop post-polio syndrome, characterized by new progressive muscle weakness, fatigue, and pain. There is no specific antiviral treatment for poliomyelitis. Management is supportive and includes physical therapy, orthopedic interventions, respiratory support when needed, and rehabilitation to maximize functional recovery. Prevention through vaccination remains the cornerstone of disease control. Two highly effective vaccines exist: the inactivated poliovirus vaccine (IPV, Salk vaccine) and the oral poliovirus vaccine (OPV, Sabin vaccine). Global vaccination campaigns led by the Global Polio Eradication Initiative have reduced wild poliovirus cases by over 99% since 1988, though the disease has not yet been fully eradicated worldwide.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

Common questions about Poliomyelitis