Asia is one of the most affected areas when it comes to the influenza A H5N1, or bird flu. Countries like China, Korea, India or Vietnam had to face the bird flu pandemics. In the year when all Asia was thinking about the tsunami that swept across the Indian Ocean another disaster occurred. Two children died in Vietnam because of the virus causing bird flu. This problem occurred in 2005 could lead to even more damage than the disastrous tsunami so a special attention was given to it.

We can also mention the flu pandemic in 1918 that killed more than 20 million people all over the world. Remembering about it the specialists began to worry about another pandemic.

The occurrence in humans of this type of virus that is mostly common among birds gave the specialists a sign that viruses are beginning to change or even mutating. This meant a threat for the whole population.

H5N1 is a virus that usually affects birds. It occurs is wild birds that are not affected. These birds spread the virus among the domestic birds which are in danger. The virus affects their internal organs and may lead to death in most of the cases.

More important is that H5N1 is getting more and more common among birds. The favorite area is Asia. The virus spreads quickly and it is being shed in the birds? saliva, nasal secretions or faeces. At least 9 birds out of 10 die after developing this virus.

H5N1 is the virus that realized the crossing of the species barrier. In 1997 it was registered the first case of bird flu virus passed to a human. This took place during the outbreak of avian influenza among poultry in Hong Kong. Because of this virus six people died.

Some specialists believe that new flu pandemics will occur in the same regions as before. The believed cause is that people live close to their animals that can be carrying the virus. As an example we might say that a domestic duck may carry H5N1 without symptoms and only after a period to release it.

In the last years the health organizations got to the conclusion that more than 150 people died because of bird flu. The reported cases of infected people are higher, up to 264 cases.

A greater problem is the conclusion of a study that says that besides birds, mice and cats may become infected too. This proves that the virus mutates and may, anytime lead to a human H5N1 pandemic.