[FoRK] avian flu/home grown/PastFutureTense

Tracie K Meyer con10gent_sentience
Thu Oct 13 10:54:52 PDT 2005


Experts fear escape of 1918 flu from lab

New Scientist | October 21 2004

The 1918 flu virus spread across the world in three months and killed at
least 40 million people. If it escaped from a lab today, the death toll
could be far higher. “The potential implications of an infected lab
worker – and spread beyond the lab – are terrifying,” says D. A.
Henderson of the University of Pittsburgh, a leading biosecurity expert.

Yet despite the danger, researchers in the US are working with
reconstructed versions of the virus at less than the maximum level of
containment. Many other experts are worried about the risks. “All the
virologists I have spoken to have concerns,” says Ingegerd Kallings of
the Swedish Institute for Infectious Disease Control in Stockholm, who
helped set laboratory safety standards for the World Health
Organization.

Work on the 1918 flu virus is not the only worry. Some experiments with
bird flu have also been criticised as dangerous (New Scientist print
edition, 28 February 2004).

Kallings and others are calling for international discussions to resolve
the issues related to such work. “It is time for influenza scientists to
find a consensus on containment,” she says. John MacKenzie of the
University of Queensland in Australia, who investigated how the SARS
virus escaped from high-level containment labs in east Asia on three
occasions after lab workers became infected, agrees. “A meeting would be
beneficial.”


Gene sequencing 


The researchers working on the 1918 virus say their work is vital to
understand what changes make flu viruses dangerous. So far five of the
1918 flu virus’s eight genes have been sequenced, using fragments
retrieved from victims of the pandemic. Several teams have added one or
more of these genes to modern flu viruses, or plan to – in effect
partially recreating the long-vanished pandemic virus.

The latest work was done by Yoshihiro Kawaoka at the University of
Wisconsin at Madison. His team showed that adding the 1918 gene for the
surface protein haemagglutinin to modern viruses made them far deadlier
to mice. The researchers also found that people born after 1918 have
little or no immunity.

The team started the work at the highest level of containment, BSL-4, at
Canada’s National Microbiology Laboratory in Winnipeg. Then they decided
the viruses were safe enough to handle at the next level down, and did
the rest of the work across the border in a BSL-3Ag lab in Madison. The
main difference between BSL-4 and BSL-3Ag is that precautions to ensure
staff do not get infected are less stringent: while BSL-4 involves
wearing fully enclosed body suits, those working at BSL-3Ag labs
typically have half-suits.

Kawaoka told New Scientist that the decision to move down to BSL-3Ag was
taken only after experiments at BSL-4 showed that giving mice the
antiviral drug oseltamivir (Tamiflu) in advance prevented them getting
sick. This means, he says, that if all lab workers take oseltamivir
“they cannot become infected”. 


Contradictory results 


Yet this assumes that the mouse results apply to humans. And the
findings have not been published. In similar experiments, Terrence
Tumpey’s team at the US Department of Agriculture’s poultry research lab
in Athens, Georgia, got quite different results: they found that mice
given oseltamivir still got sick and 1 in 10 died. It is not clear why
Kawaoka’s mice fared better.

What is more, all the safety precautions are aimed at preventing escape,
not dealing with it should it occur. If any of Kawaoka’s lab workers are
exposed to the virus despite all the precautions, and become infected
despite taking oseltamivir, the consequences could be disastrous. 

“I experienced disbelief…regarding the decision to relocate the
reconstructed 1918 influenza strain from a BSL-4 facility to a BSL-3
facility, based on its susceptibility to antiviral medication,” Ronald
Voorhees, chief medical officer at the New Mexico Department of Health,
wrote on ProMED-mail, an infectious diseases mailing list.

Yet Kawaoka’s decision does comply with the US National Institutes of
Health guidelines for BSL-3 agents: those causing “serious or lethal
human disease for which preventive or therapeutic interventions may be
[its italics] available”. In fact, he is considered unusually cautious.
“Kawaoka should be applauded for using BSL-4 at all,” says Richard
Webby, a flu researcher at St Jude’s Children’s Hospital in Memphis,
Tennessee.


Exposing monkeys 

By contrast, the team in Georgia, the first to experiment with
genetically engineered 1918 viruses, did all its work at BSL-3Ag.
Meanwhile, Michael Katze at the University of Washington at Seattle is
planning to expose monkeys to aerosols of 1918-type viruses at BSL-3, a
step down from BSL-3Ag. The recent SARS escapes were from BSL-3 labs.

“We would have to do any such work at BSL-4,” says John Wood of the UK’s
National Institute for Biological Standards and Control. In the US, the
differing standards applied by different groups are due to the fact that
experiments on engineered viruses such as the 1918 flu are approved on a
case-by-case basis by Institutional Biosafety Committees (IBCs),
composed of local scientists and officials. Critics say these are free
to interpret the official guidelines in a way that suits them.

“There is no effective national system to ensure consistency,
responsibility and good judgement in such research,” says Edward Hammond
of the Sunshine Project, a biosecurity pressure group in Austin, Texas.
In a review of IBCs published this month, he found that many would not
provide minutes of recent meetings as required by law. 

He says the IBC that approved the planned 1918 flu study at the
University of Washington considered only one scenario that could result
in workers being exposed to airborne virus – the dropping of samples.
Its solution: lab workers “will be trained to stop breathing”.
=======
/tkm
-tkm
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When everything is as it was in my childhood
Violent,vivid,and of infinite possibility:
That the sun and moon broke over my head.-preface,
'Feast of Snakes'
 

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