Definition

Usually referred to as the flu or grippe, influenza is a
highly infectious respiratory disease. The disease is
caused by certain strains of the influenza virus. When the
virus is inhaled, it attacks cells in the upper respiratory
tract, causing such typical flu symptoms as fatigue,
fever and chills, a hacking cough, and body aches.
Influenza victims are also susceptible to potentially lifethreatening
secondary infections. Although the stomach
or intestinal