Causes of the Global Spread
Transmission
Swine flu is transmitted from human to human not from pig to human. All it takes for swine flu to spread from one person to another is a cough or a sneeze. If an infected person coughs or sneezes in the presence of one or more uninfected people, then it is very likely that many of the uninfected people could get swine flu as it is highly contagious. When an infected person coughs, tiny droplets of saliva or mucus are released into the air then settle on a surface. If someone’s hands comes into contact with this surface and then they touch their eyes, nose or mouth they could become infected.
Trade
In our world today viruses can spread much faster because of the amount of import and export (trade) that goes on internationally. Many years ago trade was not as big so viruses would tend to stay in a country rather than spread to other countries. When goods travel from place to place tiny droplets containing the virus could be sent with them and end up starting a spread of swine flu overseas. Mexico’s main exporting countries are USA, Canada and Germany and in all of these countries there were over 100,000 cases of swine flu. Mexico is the largest exporter of refrigerators and plasma TVs in the world. Today these electronic items are widely used all over the world.
Transportation
Transportation also has a major effect on the spread of swine flu. Air travel is probably the largest cause of the international spread of the virus because airports are like a breeding space for viruses. Airports are where many people from different countries of the world could come into contact. This results in the virus spreading rapidly to all parts of the globe. Within countries public transport is very common. In the USA, public transport is used 35 million times a day and in 2011 public transport was used 10.2 billion times so millions of people could potentially come into contact with the virus each day. In busy cities the rate of the spread of H1N1 is rapid because of the amount of contact made between people.