Bird Flu Center

Bird flu is nowadays the highlight of health related conferences, however its cause can be traced back to other influenza epidemics.

The common influenza, usually referred to as the flu, is the name attributed to a respiratory illness triggered by specific flu viruses. It can cause simply a mild discomfort or even severe illness, in extreme cases leading to death. Certain groups are more exposed to the virus: older people, young children and people already affected by other health conditions are more likely to contract the virus.

Flu viruses which can infect birds bear the name of avian influenza. Also, of the three types of flu (A, B and C) that exist, only the influenza A virus affects birds. This, in turn, comprises of subtypes and strains of the virus, which are either low pathogenic (their effects on the poultry is mild and the mortality is quite low) or highly pathogenic. The latter is known to be a form of bird flu which can cause severe illness and have a high rate of mortality among the fowls. Both low and highly pathogenic viruses of the bird flu type have been known to affect humans in recent years and their effect has ranged from mild to severe and irreversible effects on the human body, eventually causing death. Such is the case with the H5N1, H7N3 and H7N7 viruses. Direct contact of the human victims with infected birds or consumption of such untreated meat is proven to be the main cause of bird flu infections.

The name or symbolization of the avian flu viruses derives from combinations of the 3 basic types of influenza A viruses (H5, H7 and H9) with different types of neuraminidase surface proteins (e.g. N1, N3, N7, N9).
General influenza viruses are prevented through the use of vaccines. However these viruses are also very dynamic and in continuous evolution. Small, gradual changes in the structure of a virus are known as antigenic drift. As the virus produces new strains, these are not instantly recognized by antibodies that usually fight off the flu. Thus people can become infected with the virus more than once and proper prevention of this is vaccination every year.

A more important and dangerous mutation is the antigenic shift, by which a completely new influenza A type of virus develops. This usually occurs either by a transmission of the virus from animals (more specifically poultry) to human, or by a combination of human influenza A and animal influenza A genes, giving birth to a completely new subtype. It is believed it takes about 3 months for a vaccine to be developed after the appearance of a new virus strain, so quick action is important when evidence of such mutations is present. If a new subtype of influenza A virus is highly pathogenic and can find a way of being transmitted easily from person to person, then an outbreak of an influenza pandemic is very likely to occur. Such is the case with the current bird flu virus, that such a pandemic is highly possible. That being the case, specialists warn such a world wide epidemic could claim the lives of up to 150 million people.

Although efforts are constantly being made to research and produce effective medical treatment and vaccine for the bird flu, the virus is expected to cause many more infections before it is under control.