The H1N1 influenza strain that is commonly referred to as 'Swine Flu' was first observed during an epidemic in around 1918. The virus that causes the influenza is usually transmitted via pigs, hence the name. The first-hand cause of swine flu is proximity to pigs kept in unhygienic pig pens. However, this phenomenon is not very common, and most of the time, the humans do not suffer from the influenza. They act as passive carriers.

The virus then spreads between humans in the same way, as any flu or cold does. Any direct contact with a person affected with swine flu puts you in risk of contracting the virus. Since this is a new strain of virus, people have not developed immunity to this strain.

The infected person, whenever he or she coughs or sneezes, spreads the virus with his/her body fluids within the radius of about three feet. Anyone who comes in contact with the droplets within 24 hours has a very high chance of contracting the infection. The virus can be only dangerous if the secretions come in direct contact with the nose, mouth, or even the eyes of people in the range of the infected person. This could be directly from the suspended particles, or indirectly, if you touch contaminated objects. A few of the common items prone to shelter the viruses are: remote controls, doorknobs, door handles, railings, cups, tumblers, computer keyboards, steering wheels, cigarettes, lighters, telephones, payphones, etc.. Any item/area accessed by multiple people is a high-risk area/item.

Understanding the causes of swine-flu is an important step to prevention of the infection. Once you are aware of the high-risk areas or items, you need to make a conscious effort to ensure that you sanitize your hands or wash them if you suspect them of having had contact with infection. It may not be possible for you to always avoid high-risk areas like buses, trains, ticket windows, shopping malls. Thus the next best step to ensure you stay free from infection and also protect your near ones is to take necessary precautions and immediately visit a hospital if you detect any symptoms of the disease.

It is also your responsibility to not spread the virus if you have contracted it. Use a face-mask in public places and wipe any surface that you suspect of having been infected with sanitary wipes. The safest way to stop the infection is by preventing cross-contamination.