There are three types of influenza viruses; A, B, C.
    Influenza A includes the H1N1 and B viruses that cause seasonal epidemics of disease almost every winter in the United States.  Influenza type C infections cause a mild respiratory illness and are not thought to cause epidemics.
    Definition: a contagious respiratory illness caused by influenza viruses.  It can cause mild to severe illness.  Flu signs and symptoms: Fever or feeling feverish, chills, cough, sore throat, runny or stuffy nose, muscle/body aches, and fatigue.  It's important to note that not everyone with the flu will have a fever.
    Incubation: 1-7 days (viral shedding can begin 1 day before illness onset).
    Exclusion: Exclude from school until fever free for 24 hours without the use of fever-reducing medications.