Japan had the outbreak of highly pathogenic H5N1 bird flu in 2004 for the first time in 79 years. In the Jun of 2005, there was an outbreak of H5N2 bird flu this time in a chicken farm in Ibaraki prefecture.

The case of 2004 was probably caused by migratory birds, and the infection source of the case of 2005 was probably caused by an imported bird vaccine.
As the H5N1 virus have started to be transmitted to human beings often since 2003, the number of infected patients and deaths has kept increasing. The infected area is spreading from Southeast Asia through China to Turkey and Iraq in 2006. WHO has announced that as of April 4^th 2006, 191 people had been infected and 108 died in nine countries, Vietnam, Indonesia, Thailand, China, Cambodia, Turkey, Iraq, Azerbaijan and Egypt. Most of the human cases are caused by a contact with infected birds like chickens. Even though its bird flu, you can get infected if you take in so many viruses. On the contrary, there are also infection reports of patients who have never had a contact with infected birds. Although it is believed now that there is little possibility of human-to-human infection, we can’t deny the possibility that new-type virus appears from the bird flu virus that had intragenic recombination as it repeats infection to humans. Besides, the longer epidemic continues among birds, the more mutation can occur, which can generate new-type virus that can transmit to humans.

The most dangerous bird flu virus now is the one discovered in Turkey. It is changing from bird virus to human virus. Spanish flu had changed 10 spots of its gene before it transformed bird virus to human virus. Now the virus in Turkey has already changed 4 spots of those 10. The specialists are very cautious about outbreak of new-type virus now as the possibility is getting very high. It is as if the fuse of a new-type virus bomb is lighted and the explosion moment is getting closer slowly.

The appearance possibility of new-type flu is high in Southern part of China or Southeast Asia, where people live closely with birds and swine. However, now that bird flu has spread so worldwide, new-type flu can appear anywhere in the world.