Influenza, commonly known as “flu”, is an infectious disease caused by an influenza virus. Symptoms can be mild to severe. Influenza spreads around the world in a yearly outbreak. In the Northern and Southern parts of the world, outbreaks occur mainly in winter while in areas around the equator outbreaks may occur at any time of the year. The flu is highly contagious and spreads through contact with an infected person.
The virus primarily spreads through the air from coughs or sneezes. It can also be spread by touching surfaces contaminated by the virus and then touching the mouth or eyes. A person may be infectious to others both before and during the time they are showing symptoms. Frequent hand washing, as well as yearly vaccination, reduces the risk of viral spread.
These symptoms typically begin two days after exposure to the virus and most last less than a week. The cough, however, may last for more than two weeks. The most common symptoms include: