Scientists renew warnings over a bird flu pandemic

Scientists have again renewed their warnings about the potential global effect of a flu pandemic on health and economy.

Experts are now estimating that a fifth of the world's population could be affected, with 30 million needing hospital treatment and around 7.5 million dying and they also warn of the damage to the world's economy - such a pandemic would have ramifications for international trade as well as the effect of death and illness.

Experts from Holland and the U.S. are calling for a unified global approach to the problem as the only means by which the pandemic can be contained.

Outbreaks of the H5N1 bird flu strain in south east Asia, which has, according to the World Health Organization (WHO), caused a total of 53 confirmed human deaths, have raised the level of alarm.

WHO estimates that up to 60% of humans infected by the virus have died, and all the signs point to the virus spreading between humans, although so far not in the feared mutated form which could fuel a pandemic.

In a case in Thailand it appeared that there was the probable transmission of the virus from a girl who had the disease to her mother, who also died.

Health experts fear that if the H5N1 virus did mutate and spread amongst humans, it would do so rapidly and affect millions, and they have repeatedly warned that such a pandemic would be far worse than the one which occurred in 1918, which killed between 20 and 40 million people.

Work by scientists to develop a vaccine against bird flu has been hampered by not knowing what form it might take, should it spread amongst humans.

Also the situation is made more difficult because some countries, including the UK, have announced plans to stockpile millions of doses of anti-retroviral drugs which could be used to treat people during a pandemic.

A team from the Dutch Erasmus Medical Centre led by Dr Albert Osterhaus, said there was currently a lack of coherence in how countries tested for avian flu in people, and in how the effects of the disease were monitored.

The scientists want better surveillance of bird populations to assess which strain of bird flu they are carrying and say that in order to limit the effects of flu on public health and livestock production, integrated and effective action is urgently needed, rather than ad-hoc responses at a national level. They say a global task force, including human and animal health experts, as well as health policy advisors needs to be set up under the auspices of the WHO.

Professor Michael Osterholm, from the Centre for Infectious Disease Research and Policy at the University of Minnesota in Minneapolis, also says that a pandemic flu outbreak will trigger a reaction that will change the world overnight. The response to the severe acute respiratory syndrome (SARS) epidemic will be repeated, with countries greatly reducing and even ending foreign travel and trade, and even though these efforts are doomed to fail given the infectiousness of the virus and the volume of illegal crossings that occur at most borders, government officials will feel compelled to do something to demonstrate leadership.

It has the potential for global, national and regional economies to come to ground to a halt, and countries are looking at the vaccine issue through myopic lenses, says Osterholm.