Bird Flu Virus

Bird flu virus is also known as avian influenza virus. This virus is responsible for the life threatening avian flu disease. This virus is not naturally generated in humans.

It is naturally originated in wild birds that carry this virus in their intestine. The carriers do not get affected by this virus very often. The virus is transmitted from these carriers to domesticated fowl and sometimes to humans.

Avian flu virus has severely affected the poultry business in Asia. It has also taken away many lives around the world. This virus is very dangerous but it is not easily transmitted to humans. The symptoms of the infection to this virus are similar to normal influenza. The normal symptoms are fever, cough, sore throat and muscle aches. There are many types and subtypes of this virus. All these strains of the virus are equally dangerous.

Types an subtypes of the virus

There are mainly three types of this flu viruses: A, B, and C. In all these strains only influenza A viruses are further classified by subtypes on the basis of the two main surface Glycoproteins- Hemagglutinin and Neuraminidase.

Bird flu virus A subtypes and B viruses are also classified by strains. There are various types of strains of influenza B viruses and of influenza A subtypes. New strains of the viruses appear and replaces older strains. Humans can be infected by any these viruses. The most common subtypes of this virus that are circulating worldwide are H1N1, H1N2, H1N3 and H5N1 viruses.

How this virus changes

Avian flu is very dynamic and the growth of this virus is also very fast. This virus changes in two different ways. The ways are antigenic shift and antigenic drift. Mostly bird flu virus changes in the antigenic drift and occasionally to antigenic shift.

Antigenic drift may refer to small, gradual changes at the time of mutation in the two genes that produces the proteins, Hemagglutinin, and Neuraminidase. Antigenic shift refers to a major change in the structure of the virus. Due to these changes, it is difficult for the antibodies to fight against the bird flu viruses.