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The avian flu story so far
Four conditions for a pandemic:
1) the viral strain must be a new one; 2) humans
must not have any immunity to this new virus;
3) the strain must be sufficiently virulent; 4)
the virus must be able to spread from person to
person. With H5N1, we've met three out of the
four conditions, which is why public health agencies
are worried.
Human cases: 184 laboratory
confirmed; 103 fatalities
So far all infections have been caused by people
in direct or close contact with sick or dead birds
infected with H5N1; none have been person to person.
Countries affected: Human
fatalities have occurred in Asia and the Middle
East. Vietnam has had the highest number of human
H5N1 deaths: 93 infections, 42 fatalities. Turkey
has had 12 documented cases, four of them fatal.
The UN has predicted that bird flu will land in
the Americas within six to 12 months.
The virus: H5N1 is a
type A influenza virus; the most variable form.
In late March, American researchers announced
that H5N1 has split into two distinct strains,
which they say could make the virus more difficult
to control.
A week later, another team of
researchers from the US and Japan said they'd
found out why H5N1 isn't easily spread to people:
the virus is found deep in the lungs rather than
in the mucous lining of the mouth, throat and
nose, making it more difficult to transmit.
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An influenza pandemic is just
around the corner, warns the World Health Organization.
Although nobody can predict whether the next pandemic
will be from an avian flu, Canada isn't taking any chances.
The feds are updating their pandemic preparedness plan
and have commissioned a mock vaccine that can be adapted
to whatever strain comes along.
The Canadian Public Health Agency
is also urging doctors to be on the lookout for the
deadly H5N1 virus in patients now. "Doctors should be
aware of patients coming back from countries that are
infected with avian flu, particularly countries with
human cases," says Dr Arlene King, Director General
of Pandemic Preparedness.
But some physicians say they're
suffering from pandemic burnout before the virus has
even landed.
"We've had nine years experience
with H5N1 and found that it doesn't spread effectively
from person to person," says an exasperated Dr Richard
Schabas, who was Ontario's Chief Medical Officer of
Health from 1987-97 and current medical officer of health
at the Hastings and Prince Edward County Health Unit.
"The worry is that from some magical process it's going
to suddenly infect humans. I find that baffling."
Dr Schabas has been at the centre
of an avian flu controversy since he wrote an op-ed
piece entitled "Stop Chasing a Phantom Flu" for the
Globe and Mail. He insists H5N1 poses no imminent threat
and that governments are wasting millions of dollars
so far on drug stockpiling and other preventative measures.
IS
THE SKY FALLING?
Although the Public Health Agency is steering away from
WHO-style dire predictions, its attitude is 'better
safe than sorry' — particularly after the SARS
fiasco. "Our view is we don't know when the next pandemic
will occur," says Dr King, "we don't know what will
be the cause, and we don't know how severe."
Though Canada doesn't have any
traces of avian flu at the moment, she insists doctors
should be on high alert.
She shouldn't hold her breath,
according to Dr Schabas. Most Canadian physicians take
the same view as him, he says. They aren't paying much
attention to the bird flu debate and simply don't consider
it a real threat — with reason. "There has been
no meaningful debate, no journals have showed interest,"
he says. "The evidentiary basis is far too weak, far
too sketchy."
Dr Schabas firmly places the blame
for misinformation and confusion with the WHO. He says
they have vested interests in getting the public riled
up about bird flu, namely to get more funding. "It's
the same people who said we're all going to die from
SARS, we didn't. Then we're all going to die from West
Nile, we didn't. Then Ebola, then Lassa fever, and half
a dozen others I can't even remember."
He adds that inaccurate reporting
in the media has resulted in everyone mixing up influenza
preparedness with an avian flu pandemic. He accepts
that the world is probably due for an influenza pandemic
in the next 40 years, but he doesn't believe it will
be H5N1.
Nevertheless, Canada is erring
on the side of caution. The national flu pandemic preparedness
plan is preparing for up to 138,000 people in need of
hospitalization, with anywhere between 11,000-58,000
deaths. The economic impact is estimated to be between
$10 and 24 billion.
"Our job is to try and mitigate
as much as possible," said Dr King, "we know our healthcare
system is running at capacity right now, we will have
to try and do our best."
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