View Full Version : Britain Warned Over Bird Flu Pandemic

08-04-2005, 08:44 AM
Britain warned over bird flu pandemic


08:43am 4th August 2005

Britain would be "overwhelmed" if a deadly strain of pandemic bird flu reached its shores, a leading expert warned today.

Once the virus spread as far as the UK it would be impossible to contain, said Professor Neil Ferguson.

The only chance of averting a global disaster costing many millions of lives would be to snuff out the strain rapidly at its point of origin in south-east Asia.

Talk here » The H5N1 avian flu strain, which infects poultry, has already killed more than 50 people in the region.

Scientists and public health experts are bracing themselves for the terrifying consequences of the virus mutating into a form that can pass from one person to another.

The result could be a wildfire of infection spreading rapidly across the globe and leaving a trail of death in its wake.

The virus is so lethal it could kill even more people than the 1918 Spanish flu pandemic, which claimed between 20 and 40 million lives.

Computer simulations have now shown that even if the strain became transmissible between humans it could be halted in time - but only with swift, co-ordinated international action.

The new deadly version of the virus would have to be identified while confined to only about 30 people, Prof Ferguson's team found.

Antiviral drugs would have to be distributed rapidly to the 20,000 individuals nearest those infected, and the outbreak limited to fewer than 200 cases.

Failure to take action swiftly enough would result in catastrophe, say scientists. If the virus got as far as Britain, it would effectively be too late.

Prof Ferguson said: "What can we do if it hits our shores? We couldn't stop it. There would be a constant number of new cases and we would be overwhelmed very rapidly."

Urgent research was under way to see to what extent deaths could be prevented in the UK, he said.

Two separate teams of scientists investigated the worst case scenario for bird flu and came to similar conclusions. Both models focused on Thailand, one of the places at highest risk from 'bird flu.

Prof Ferguson's group found that an international stockpile of three million courses of antiviral treatment would be enough to contain an outbreak. But it would mean being able to deploy the drug anywhere at very short notice.

The other team, led by Dr Ira Longini, from Emory University in Atlanta, Georgia, in the United States, simulated a sub-population of 500,000 in which individuals mixed in a variety of settings, including households, schools, workplaces and a hospital.

Social meeting places such as markets, shops and temples were also included. The researchers found that targeted use of antiviral drugs could contain an outbreak if action was taken within 21 days.

Dr Longini's team calculated a reproductive number for the virus of about 1.6. This represents the average number of people within a population a single person with the disease is able to infect.

With a moderate reproductive number of this size, an outbreak could be contained with 100,000 courses of antiviral treatment, said Dr Longini.

Prof Ferguson's team worked out a slightly higher reproductive number of 1.8. Even such a tiny increase in the reproductive number meant far more treatment courses were needed.

Dr Longini said: "Our findings indicate that we have reason to be somewhat hopeful. If - or, more likely, when - an outbreak occurs in humans, there is a chance of containing it and preventing a pandemic. However, it will require a serious effort, with major planning and co-ordination, and there is no guarantee of success."

Rapid spread
The two research papers appear in the latest issues of the journals Nature and Science. A news briefing in London heard that if a pandemic strain emerged and nothing was done, it would cross international boundaries in just two to three months.

In just one year, half the world's population - more than three billion people - would be infected. There have been 108 cases of H5N1 flu and 54 deaths recorded so far among people exposed to poultry in Vietnam, Thailand and Cambodia.

Recently an outbreak of the same strain was detected in wild migratory geese at Qinghai Lake in western China - the first confirmation that the virus can pass between wild birds.

Experts are worried that migrating birds might spread the virus to densely populated regions of southern Asia, or even Europe.

Dr Peter Aldhous, Nature journal's chief news and features editor, who recently spent 10 days researching avian flu in Vietnam, said: "What these new papers do is indicate for the first time that it is theoretically possible to contain a pandemic strain of influenza at its point of origin.

"That's very significant, because it could save millions of lives and billions of pounds." It was important for the World Health Organisation and other public health bodies to look very carefully at the findings, he said.

But he warned that simply telling Asian countries what to do would be counterproductive. "Vietnamese authorities in particular are deeply suspicious of foreigners interfering in their affairs," said Dr Aldhous.

Currently the antiviral drug Tamiflu, made by Swiss-based pharmaceutical company Roche, stands the best chance of curbing pandemic bird flu. It is effective against multiple strains of influenza and can also be used as a preventative treatment.

Prof Ferguson said he understood Roche was prepared to make free donations of Tamiflu to the World Health Organisation to help meet the threat.

In talks
A spokeswoman for Roche said: "We are in discussions with the WHO but details are still being finalised."

She said Roche had increased production of Tamiflu eight-fold since 2003. However, details of its production capability were confidential.

According to New Scientist magazine, the WHO currently has 120,000 courses of Tamiflu treatment.

A Department of Health spokesman said: "We are aware of this research. The World Health Organisation is the international agency with responsibility for co-ordinating the international response to a potential or actual influenza pandemic.

"The UK works closely with the WHO, and has donated £500,000 to WHO to support surveillance in SE Asia - recognising that key to managing such an event is to identify it at the earliest opportunity.

"The WHO has indicated its intention to build up an international stockpile in line with the quantities of antivirals scientists predict would be needed to control the initial outbreak in the way described."