A virus is a microscopic organism that causes infection and
disease. Viral illnesses can range from mild to severe. Some examples are the common cold, West Nile virus, polio, and smallpox.
July 9, 2012
E. Gregory Thompson, MD - Internal Medicine & Christine Hahn, MD - Epidemiology
How this information was developed to help you make better health decisions.
To learn more visit Healthwise.org
© 1995-2013 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.