Causes and Risk Factors

Influenza is caused by three types (strains) of viruses: influenza A, B, and C. Influenza A and C infect multiple species whereas influenza B usually affects only human beings. Type A is associated with worldwide epidemics of influenza and B typically leads to smaller, more localized outbreaks. Type C influenza viruses have never been associated with a large epidemic and are responsible for causing mild respiratory infections similar to the common cold.

As mentioned earlier, influenza is a highly contagious infection. The flu virus can spread in the form of airborne droplets that are dispersed in the air by coughing or sneezing. Inhaling these contaminated droplets can immediately infect a healthy individual. Here are some of the risk factors of influenza:

	Age: Anyone can be affected by influenza but children and elderly people (65 years or older) may develop serious complications. Pregnant women are also equally at risk.
	Close contact with infected individual: Touching or sharing clothes, utensils, or other objects used by the infected individual may increase the risk of contracting influenza.