the world would be facing an extremely severe problem

Flu viruses can travel around the world so much faster today than they could a hundred years ago. International travel and trade in livestock means that in a couple of days an influenza virus in Europe can find its way to Asia and vice versa. For example in China European influenza viruses are becoming more common among pigs and researchers recently released information showing that out of the three different strains of Chinese swine flu, one of them is a European one.

The researchers who have been examining swine flu viruses for twelve years around Singapore and China said that the importation of different breeds of pig to improve the quality of livestock has had a detrimental effect on containing individual swine flu viruses. Their research was published in the journal Nature.

The danger of different viruses meeting each other is that they can mutate into more dangerous forms. Influenza viruses are always changing and adapting to their conditions but whereas previously they mutated very slowly there's a concern among scientists that should for example the regular H1N1 swine flu virus link up with a more dangerous H5N1 bird flu virus the resulting virus could be lethal and kill millions of people.

At present the H5N1 bird flu virus is very hard for humans to catch, but the H1N1 swine flu is much more contagious among humans. If the H5N1 bird flu virus which has killed about 50% of those humans who have contracted it becomes as contagious as H1N1 the world would be facing an extremely severe problem.

It's obviously pretty complicated stuff and that is why scientists are constantly monitoring any changes in influenza patterns not only among humans but also in animals.

There were some people who felt that the World Health Organization overreacted to the H1N1 swine flu virus which spread around the world recently but they tended to be those who were not fully conscious of exactly how dangerous certain influenza viruses can be.

All you need to do is look at the figures for the Spanish Flu which appeared after the First World War which killed millions to understand exactly how and what these influenza viruses are capable of.

The drugs Tamiflu and Relenza have been shown to massively reduce the likelihood of severe health problems and death in individuals who have contracted the H5N1 bird flu virus.