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St. Jude's children's hospital on the front line in bird flu fight
By Maggie Fox, Reuters
September 18, 2005
MEMPHIS -- It seems an unlikely place to launch a war against a bird virus health officials believe could soon mutate into a human pandemic that will kill millions -- a hospital filled with children fighting devastating genetic diseases and rare cancers.
But Robert Webster likes the daily reminders, in the form of children pulled around in colorful wagons or sitting propped against a mother's lap, that the work begun in a laboratory has real life-and-death outcomes.
And the private funds raised by St. Jude's Children's Research Hospital in Memphis are helping Webster and his team of international virus specialists fight what some say may be the biggest threat to humanity right now -- avian influenza.
''We could be heading for a global catastrophe," Webster said in an interview in his corner office overlooking the expansive hospital campus.
If bird flu were to start spreading among people, more than 25 million hospital admissions and up to 7 million deaths globally would follow within a short period, according to British researchers who model epidemics using computer programs.
Webster's team works out of high-tech labs set up by the St. Jude organization, launched by Lebanese-American entertainer Danny Thomas in the 1950s to care for children with cancer and other hard-to-treat diseases.
Ever since Webster and his colleagues discovered that aquatic birds such as ducks were the natural reservoirs of influenza and that the virus has several ways of changing quickly into a mass killer, he has said it is only a matter of time before a flu virus takes on a form that will kill millions of people.
''You just don't know when it is going to happen," Webster said. ''But I think some of the policy makers and politicians are starting to listen."
When Webster saw the avian flu strain called H5N1 for the first time in Hong Kong in 1997, he thought this might be it.
The virus hopped from ducks to chickens, killing chickens in a day, and infected 18 people who handled the birds, killing six, before authorities stopped it with the slaughtered of poultry and closings of bird markets.
No one thought it was gone for good, and when flu specialists first heard about a mysterious virus that was killing people in China's Guangdong Province at the end of 2002, they feared that H5N1 had come back. In fact, it was Severe Acute Respiratory Syndrome.
The panic over SARS upstaged the reappearance of H5N1 in China in 2003, and this time the authorities did not act so quickly or decisively.
Now it has killed or forced the slaughter of tens of millions of domestic birds in China, Vietnam, Thailand, Indonesia, Cambodia, Japan, and elsewhere. It has killed more than 60 people, although it does not yet easily infect humans or pass from human to human.
It has been found in wild birds in Mongolia and now in flocks in Kazakhstan and Russia.
''This virus keeps extending its range," Webster said. ''It is out there spreading like crazy among the wild birds of Asia."
Not everyone is convinced that migrating birds are spreading H5N1, but Webster is.
Between studying dead birds in Australia and the viruses that infected them in London, Webster and colleagues worked up the idea that influenza viruses originate in birds -- mostly ducks.
These natural hosts, or reservoirs, do not usually become ill when infected, but incubate and spread the viruses.
But how do the viruses acquire the ability to infect new species, and how does their disease-causing nature change? Webster also helped discover how viruses do this.
One way is by steady mutation. Influenza is an RNA virus, meaning it is error-prone because it only uses one copy of the genetic code to replicate itself. That results in frequent variation, or mutation, of the virus, and ultimately one form will spread from person to person.
''The clock keeps ticking. Every time this virus replicates, it makes mistakes," Webster said. ''Sooner or later it will make the mistakes that will allow it to go human to human."
There is a quicker way. If two different viruses are in a cell together, they can swap pieces of their genes, a process called reassortment. ''It's virus sex," said Webster.
This reassortment caused the global flu pandemics of 1957 and 1968 that killed many people -- 4 million in 1968 -- because humans had no immunity to the new viruses that arose.
All it takes is for one person to become infected with H5N1 while also infected with ordinary human flu. This may have happened in 1918, when a new strain of flu killed as many as 40 million people globally, most of them healthy, young adults.
''We don't even know the mistakes it made in 1918 that allowed it to go human to human," Webster said.
Specialists in the Biosafety Level 3 lab at St. Jude's are studying the genetics of H5N1 to try to find precisely what ''mistake" H5N1 needs to make it something people can easily transmit to one another.
In this lab, with its specially sealed doors, air circulation controls, and showers to scrub down everyone who exits, it is possible to play around with deadly viruses.
Webster has been working here since 1968, when he was recruited to study influenza coincidentally just as the last global pandemic of disease was getting underway.
http://www.boston.com/news/nation/a... ird_flu_fight/
