polio

polio
Name	Poliomyelitis
Caption	Transmission electron micrograph of poliovirus
Field	Infectious disease, Neurology
Symptoms	Muscle weakness resulting in an inability to move
Complications	Post-polio syndrome
Onset	Hours to days
Causes	Poliovirus
Risks	Poor hygiene
Diagnosis	Finding the virus in the feces or antibodies in the blood
Prevention	Polio vaccine
Treatment	Physical therapy, Iron lung

polio. Poliomyelitis, often termed infantile paralysis, is an acute infectious disease caused by the poliovirus. The virus invades the nervous system and can cause total paralysis in a matter of hours. While most infections are asymptomatic, the disease can lead to permanent muscle weakness, paralysis, and even death.

Overview

Poliomyelitis is a highly contagious viral illness that has affected humanity for millennia, with evidence found in ancient Egyptian art. The disease primarily spreads through the fecal-oral route in areas with poor sanitation. The development of effective vaccines in the mid-20th century, notably by Jonas Salk and Albert Sabin, transformed the global fight against the virus. The World Health Organization launched the Global Polio Eradication Initiative in 1988, leading to the elimination of the disease from most of the world, though it remains endemic in a few countries.

Causes and transmission

The disease is caused by infection with the poliovirus, a member of the genus Enterovirus. The virus is highly contagious and spreads primarily through contact with the feces of an infected person. Contaminated food or water in areas with inadequate sewage systems are common vectors. The virus can also be transmitted through respiratory droplets, particularly in the early stages of infection. The poliovirus enters the body through the mouth and multiplies in the intestines before potentially invading the lymphatic system and bloodstream.

Symptoms and diagnosis

Approximately 70% of infections are entirely asymptomatic. In symptomatic cases, initial manifestations often resemble influenza, including fever, fatigue, and headache. A smaller percentage develop non-paralytic aseptic meningitis. The most severe form, paralytic poliomyelitis, occurs when the virus attacks motor neurons in the spinal cord and brainstem, leading to acute flaccid paralysis. Diagnosis is confirmed by isolating the poliovirus from stool samples or detecting specific antibodies in serum. Surveillance for acute flaccid paralysis is a cornerstone of global eradication efforts.

Prevention and treatment

Vaccination is the only reliable method of prevention. The inactivated poliovirus vaccine developed by Jonas Salk and the oral poliovirus vaccine developed by Albert Sabin have been instrumental in control programs. The World Health Organization recommends routine immunization as part of national childhood vaccination schedules. There is no cure for the disease; treatment is supportive and focuses on alleviating symptoms. This can include analgesics, portable ventilators, and extensive physical therapy. Historical treatments often involved the use of an iron lung for patients with respiratory paralysis.

History and eradication efforts

Major epidemics began appearing in Europe and North America in the late 19th century, causing widespread fear. The 1916 New York City epidemic resulted in thousands of cases and deaths. The development of vaccines in the 1950s, championed by the March of Dimes, marked a turning point. The Global Polio Eradication Initiative, spearheaded by the World Health Organization, UNICEF, and the Centers for Disease Control and Prevention, has reduced global cases by over 99%. Notable figures like Franklin D. Roosevelt, who was diagnosed in 1921, brought significant public attention to the disease. The Americas were declared free of the virus in 1994.

Society and culture

The disease has left a profound mark on society, influencing public health infrastructure, disability rights, and charitable fundraising. The March of Dimes, originally founded by Franklin D. Roosevelt, revolutionized medical philanthropy by funding Jonas Salk's research. Survivors' experiences, including long-term disability and post-polio syndrome, have shaped narratives in works like The Plague by Albert Camus. Annual events like World Polio Day on October 24, coinciding with the birthday of Jonas Salk, continue to raise awareness and funds for the final push toward global eradication led by organizations like Rotary International.

Category:Viral diseases Category:Eradicated diseases Category:World Health Organization essential medicines