Doctors fear 'chicken flu' may have spread among humans

The Chief Medical Officer in Britain has sent a letter to all doctors warning them about a new and deadly strain of flu. Steven Vines and Kate Watson-Smyth consider the spread of the 'chicken flu' virus in Hong Kong which threatens to turn into a pandemic.

The Hong Kong government yesterday launched an action plan to combat the so-called "chicken flu" amid fears that the virus can be spread from humans to humans, not just from poultry to animals.

The implication of this finding is that it would make the virus, known as H5N1, more likely to spread quickly in communities where infection from poultry has taken hold. Since it comes from birds, humans have no natural immunity to the disease and at the moment there is no vaccine.

In London, scientists at the National Institute of Medical Research are working round the clock to find a way of protecting people, and anyone who has recently returned from Asia with respiratory problems will be tested to see if the virus has arrived here.

Dr Robert Webster, of the World Health Organisation, who has studied the flu virus for 40 years, said it was extremely serious. "It is as contagious as ordinary flu and I do not think we are trying to scare people," he said in an interview with Newsnight. "As more and more cases happen, the likelihood of this fizzling out decreases."

Dr Daniel Lavanchy, from the division of emergency diseases of World Health Organisation, said so far there was no conclusive proof that the virus could be spread from human to human. But he added: "It is a new virus and if it passes easily to humans, as there is no immunity it will spread through the population, perhaps world-wide. There is a possibility of a pandemic."

The two latest victims of the virus are a two-year-old boy and a three- and-a-half-year-old girl who were living in the same house as a five-year- old girl who is still in hospital being treated for bird flu.

The Hong Kong authorities say that further tests are needed to confirm whether human-to-human transmission is a typical characteristic of the virus. Nevertheless, additional monitoring and preventive measures were announced yesterday, both to protect Hong Kong people and to prevent the spread of bird flu overseas. Both the WHO and the United States-based Centers for Disease Control are working closely with the Hong Kong authorities.

Margaret Chan, director of health in Hong Kong, said yesterday that although human to human transmission of chicken flu was "possible", it seemed likely that it was not being transmitted very efficiently because, if it was, "there would be hundreds and thousands of such cases in the territory by now".

Two people have so far died of chicken flu-related illnesses, another seven victims have been identified, two of whom have recovered while another two are in critical condition.

Dr Chan said that if the flu were caught at an early stage it could be treated by using the drug amantadine. If the flu is allowed to develop it can turn into Reye Syndrome which affects the nervous system and the liver, with fatal consequences.