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nonspecific respiratory illness whose symptoms resemble those of influenza but which are usually caused not by influenza virus infection but by other viruses or by bacteria.
influenza-like illnessAbbreviation: ILI
Any disease of the respiratory tract that causes cough, fever, malaise, headache, sore throat, and fatigue. ILI can be caused by rhinoviruses, respiratory syncytial virus, coronaviruses, adenoviruses, rickettsia, and other infectious microorganisms.
See also: illness