What Are the Causes of the Polio Virus?
Polio is a contagious virus that primarily causes paralysis, difficulty breathing and death. The Mayo Clinic reports that the last case of natural polio in the U.S. occurred in 1979. The polio vaccine is 90 percent effective in preventing infection, according to Medline Plus, a service of the National Institutes of Health. Therefore, persons traveling to high-risk areas, including Afghanistan, India and Nigeria, should be vaccinated beforehand. Ninety-five percent of polio cases cause minimal symptoms; however, less than one percent may result in severe nervous system complications, according to the Mayo Clinic. A person should be aware of the causes of the poliovirus and know what measures to take to avoid infection.
