Bird flu is not a very common disease and hence there are many wrong notions about it. It is not well known to everyone that there are several types of this influenza virus and the way it is contracted is also not generally known. It would be useful for everyone to have some basic knowledge about the bird flu virus. With the onset of the flu season, the spread of bird flu is of considerable worry to people in many countries. Bird flu is type A influenza virus that attacks not only birds but pigs and other animals like chicken, turkey etc. can be infected by it as well. Human beings are usually infected by A, B and C types of influenza virus. When people live close to pigs and poultry, it is possible for genetic changes and sharing to happen.
Genetic changes can transmit the virus more easily and make the virus more infectious to human beings. This spreading of the avian influenza virus can become pandemic i.e. a worldwide outbreak of the virus. Epidemics involve existing viruses and are seasonal in nature and bird flu virus is not likely to assume epidemic proportion. Symptoms like fever, muscle ache, cough, eye infections etc. which are flu like are also common to bird flu. An infected person should consult a doctor, even though there is no vaccine for the virus.
The H5N1 strain of the bird flu virus is most deadly and kills the infected animals rapidly. The virus kills chickens within hours and several infected chickens were slaughtered in many parts of Asia to contain its spread. 6 out of the 18 infected persons died in Hong Kong in 1997. A hybrid strain may be formed by swapping genes when an avian flu virus and a human flu virus infect the same host like a human being. This mutated hybrid strain in combination with human flu virus genes makes human to human transmission more efficient and can cause a pandemic. The human body then will not have any immunity against the virus.
A virus created from mixing human flu genes with bird flu genes caused a pandemic in 1957 and 1968 and killed nearly 2 million people. When the bird flu virus mutates on its own, it can cause deadly human infection. Many genetic changes have occurred in the H5N1 virus since it emerged that has made it more disease causing. It can replicate more quickly and effectively than the virus responsible for flu in human beings. The 1918 bird flu pandemic killed almost 50 million people and H5N1 like virus is said to be responsible for it.
It is believed by many scientists that a bird flu pandemic is impending as just a few significant mutations can make it happen. The culling of the poultry population in Hong Kong in 1997 is an indication of the pandemic fear. The future of H5N1 virus as it adapts and grows and spreads in human beings is not clear. While it is believed by some that it would become more lethal, others believe in the opposite i.e. it would become less effective and weaken. It is hoped that as the flu spreads among humans it would lose its virulence.
