Swine flu, also known as hog flu, or pig flu is correctly known as Swine Influenza. It is an infection by any one or many different types of swine influenza virus. Swine influenza virus (SIV) involves any strain of the influenza family of viruses endemic in pigs. Currently (as of August 2009), the known SIV strains include influenza C and the influenza A subtypes known as H1N1, H1N2, H3N1, H3N2, and H2N3. The current swine flu outbreak involves strain H1N1.

The Swine Flu virus is prevalent in pig populations worldwide. Despite this, transmission of the virus from pigs to humans is uncommon and rarely leads to human influenza. Usually exposure leads to development of resistant antibodies. When transmission causes human influenza, it is known as zoonotic swine flu. People with regular exposure to pigs (e.g. pig farmers) are at increased risk of swine flu infection. However, the meat of an infected animal poses no risk of infection if properly cooked.

The current swine flu outbreak has spread worldwide. From its origins in Mexico it quickly spread to the USA then to the rest of the Americas, Europe, Asia and the rest of the world. All continents have reported cases and no country is safe from infection. Swine flu treatments are available. Tamiflu can be used to reduce the severity of symptoms and a new vaccine has been developed for use. However, with vaccine stocks being low and difficult to produce, and the chance that the virus may mutate, there is no room for complacency. We all need to keep our guard up against this ever-present threat.