The bird flu viruses are mostly subtypes of Influenza Virus A. There are several H5 and H7 subtypes of the ‘influenza A’ virus that cause bird flu among the birds. The wild fowls are considered to be the reservoir of the bird flu virus since ages. The migratory birds carry the pathogens from place to place and in turn infect the local population of the birds causing wide spread deaths.
Till 1997, the virus was restricted to the arboreal species and pigs. They never infected humans. But, the deaths in Hong Kong and other parts of the south east Asian countries have raised alarm throughout the medical world. Though it was a known fact that bird flu viruses mutate to different kinds but this was the first time that the viruses adapted themselves to be strong enough to attack mammals including humans and dogs. This bird flu virus has been identified as the H5N1 virus, a subtype of the H5 viruses.
The complete name of this virus is HPAI A (H5N1) (highly pathogenic avian influenza virus). The present form of bird flu virus is a fast mutating virus and extremely pathogenic in form than the previous strains till date. The viruses are present in the respiratory system of many species of birds. So, the spread of the virus to any part of the world is inevitable. They are mostly carried by the migratory birds.
The H5N1 virus has mutated to a form that is capable of infesting the humans and some other mammals; and the impact could be fatal enough to kill the hosts. They generally attack the respiratory system and the symptoms are almost similar to normal flu. It has become a ‘panzootic’ virus which means it can attack any species.
The studies conducted on them show that they continually evolve through antigenic drift. They infect humans through direct contact with the infected birds or patients suffering from the bird flu. The infected birds pass the virus in the environment through their nasal secretion, saliva, feces and blood droplets. The virus moves into the human body through the nasal cavity or the mucous membrane of the eyes.
The virus H5N1 has really become a nightmare because of its kind to mutate very fast and the evolving status may take it to a very lethal form. The scientists working on bird flu are of the view that the consequence of the combination of this H5N1 virus with human flu virus may be so complicated that before anything would be thought, it would wipe out millions of lives.
Precaution is very important. So, if there is an outbreak in your area, be prepared to defy the bird flu virus with proper care and implement the methods instructed by the health department in your area.