What Are Systemic Effects of Influenza?
Systemic effects of influenza such as fever, headache and muscle pain result from the response of the immune system to the infection, rather than the virus itself. As Harvard Medical School professor Dr. Raphael Dolin explains in the 2008 edition of “Harrison’s Principles of Internal Medicine,” the influenza virus has rarely been detected outside of the lungs and airways. Instead, systemic effects are believed to be mediated by chemical messengers such as tumor necrosis factor, interferon, interleukin-6 and interleukin-8 which escape from the respiratory tract and enter the bloodstream. Once in circulation, they issue the physiological equivalent of a distress call, alerting the immune system to the presence of an infection.
