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Definition of influenza



               Acute viral infection of the respiratory tract. From Latin influentia, "to flow into"; in medieval times, intangible fluid given off by stars was believed to affect humans. The Italian influenza referred to any disease outbreak thought to be influenced by stars. In 1743, what Italians called an influenza di catarro ("epidemic of catarrh") spread across Europe, and the disease came to be known in English as simply "influenza."



1. Emerg Infect Dis, Jan 2006;12:179.

2. http://www.worldwidewords.org/topicalwords/tw-inf1.htm