Poliomyelitis, commonly known as polio, is a highly contagious viral infection caused by the poliovirus. It primarily affects the nervous system and can lead to paralysis, muscle weakness, and in severe cases, death. Polio is transmitted through contaminated food and water or direct contact with an infected person, but widespread vaccination has dramatically reduced its incidence worldwide. Efforts continue to eradicate the disease, particularly in regions where it remains endemic.