This fact sheet from the WHO outlines the basics about swine influenza, or "swine flu", including what it is, what its implications are for human health and how people become infected.

Swine flu is a highly contagious acute respiratory disease of pigs. It can sometimes cause disease in humans — either from infected pigs or, occasionally, through human-to-human transmission. It cannot be caught by eating properly handled and prepared pork.

No vaccine can stop swine flu causing illness in humans, but two classes of drugs are available. Most previously reported cases recovered fully without medical attention or antivirals.

There is a risk that swine flu could lead to a pandemic because most people are not immune to the virus. But the impact of such a pandemic is difficult to predict.

Typical symptoms resemble seasonal flu — a high fever, cough and/or sore throat. If you feel unwell, the WHO advises staying at home, resting, contacting your doctor before going to see them, and covering your nose and mouth when out of the house.

To protect yourself from swine flu, the WHO recommends avoiding contact with sick pigs or people, washing your hands regularly, practicing good health habits and following advice from local health authorities.