Date: Monday, September 28th, 2009
Source: Texas AgriLife Extension Service
Influenza, more commonly known as “the flu,” is a contagious illness caused by a virus. The flu affects the upper respiratory system, which consists of the nose, mouth, sinuses, and throat. The 2009 H1N1 flu is a new flu virus that has spread worldwide. Most people do not yet have immunity against this virus.