What is bird flu?

Bird flu - known technically as avian influenza - is a highly contagious viral disease affecting mostly chickens, ducks, turkeys, quails and other birds, and was first identified more than 100 years ago.

It can be caused by any one of about 20 different strains of the influenza virus. The recent outbreaks in Asia, however, have been largely caused by a highly contagious and virulent strain, known as H5N1. (The name H5N1 refers to the specific nature of two proteins, haemagglutinin and neuraminidase, found on the surface of the virus.)

India has detected its first cases of the deadly H5N1 bird flu strain in western Maharashtra state. The health ministry said that though no human cases had been detected so far, some people were being tested for the disease. The H5N1 strain has killed at least 90 people since early 2003, mostly in south-east Asia.

The virus can infect humans in close contact with birds. There is still no evidence that it can be passed from human to human. The European Union recently approved a series of measures to try to halt the spread of the virus, including the automatic creation of protection and surveillance zones around outbreaks in wild birds.

If the virus transfers from wild birds to poultry, "buffer zones" that could cover an entire region should be established and the transport of poultry restricted within them.

The BBC's Zubair Ahmed in the western Indian city of Mumbai (Bombay), capital of Maharashtra, says for the past few weeks there were suspicions in Nandurbar of the outbreak of the disease after deaths of thousands of chickens. A poultry owner in the area said 400,000 chickens in poultry farms had been affected by the virus.

Indian health officials have advised people against eating chicken until further notice.

Reference: http://news.bbc.co.uk/1/hi/world/south_asia/4727312.stm