Influenza, commonly known as the flu, is a viral respiratory infection. If you experience flu-like symptoms, your healthcare provider may conduct a flu test to confirm the diagnosis. In case of a positive diagnosis, your healthcare provider may prescribe an antiviral medication to combat the virus, if necessary. For optimal results, antiviral medication should be administered within two days of the onset of symptoms. This medication can help alleviate flu symptoms and potentially reduce the duration of illness by about one day.

Types of Influenza Viruses

Type A influenza viruses are found in a variety of animal species, including birds, pigs, horses, and humans. They are responsible for most flu pandemics and can cause severe illness. Type A influenza viruses are further classified into subtypes based on the combination of two proteins on the surface of the virus: hemagglutinin (H) and neuraminidase (N).

Type B influenza viruses are found only in humans and cause less severe illness than type A viruses. They are not classified into subtypes but are further divided into two lineages: Victoria and Yamagata.

Type C influenza viruses also infect humans, but they usually cause mild respiratory illness and are not associated with outbreaks or epidemics.

Type D influenza viruses primarily infect cattle but can also infect pigs and other animals. They do not infect humans.

It is important to note that the flu vaccine protects against influenza viruses of types A and B, but not type C or type D.