Polio

Swine Flu (H1N1) Vaccine Slideshow Swine Flu (H1N1) FAQ Slideshow Strep or Sore Throat Slideshow

Medical Author: David Perlstein, MD, FAAP
Medical Editor: Charles Davis, MD, PhD

• What is the history of polio?
• What causes polio?
• How is polio spread?
• What are signs and symptoms of polio?
• How is polio diagnosed?
• How is polio treated?
• Is there a vaccine that prevents polio?
• Where can one find more information about polio?
• Polio At A Glance

What is the history of polio?

Polio is caused by a virus and has been around for thousands of years. There are even Egyptian artifacts portraying individuals with typical features of post-polio paralysis. Polio has been called many different names, including infantile paralysis, debility of the lower extremities, and spinal paralytic paralysis. We now refer to the virus and disease as polio, which is short for poliomyelitis and has Greek derivation: polios (gray), myelos (marrow), and itis (inflammation).

Polio is caused by a very infectious enterovirus, poliovirus (PV), which primarily affects young children and is spread through direct person-to-person contact, with infected mucus, phlegm, feces, or by contact with food and water contaminated by feces of another infected individual. The virus multiplies in the gastrointestinal tract where it can also invade the nervous system, causing permanent neurological damage in some individuals.

Most individuals infected with polio remain asymptomatic or develop only mild flu-like symptoms, including fatigue, malaise, fever, headache, sore throat, and vomiting. In fact, the symptoms, if present, may only last 48-72 hours; however, those individuals will continue to shed virus in their stools for a prolonged period, serving as a reservoir for subsequent infections. About 2%-5% of infected individuals go on to develop more serious symptoms that may include respiratory problems and paralysis. Currently, there is no cure for polio; only vaccination can prevent the spread of the disease, and although in the developed world it is almost unheard of, globally, polio remains a fairly common disease. Originally, international organizations believed it possible to eradicate polio by 2000, though this has been more difficult than initially hoped for.