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Deadly flu: `The only question is when'

TheStar.com - Deadly flu: `The only question is when'

Avian's arrival called inevitable
Experts fear global pandemic
Not if, but when for outbreak of disease: Experts

Avian flu virus is possible candidate for global infection

LYNDA HURST
FEATURE WRITER

The deadly avian flu virus is slowly but surely making its way around the world.

It now appears all but inevitable that it will arrive in North America this year or next, via migrating birds or, more likely, unwitting travellers, as with SARS in 2003.

The virus has already ravaged the poultry stocks of Southeast Asia and millions of peoples' livelihoods. It has also begun to kill other animals, including pigs, tigers and civet cats.

More forebodingly, if still only sporadically, it has crossed over into humans.

In the last two years, at least 109 people have caught the respiratory virus after being in close contact with diseased poultry. With little or no immunity — and no vaccine — about 60 of them died. Perhaps more.

China isn't saying, though it was there that this year's outbreak began, in April, with 6,000 dead wild birds.

The threat is now on Europe's doorstep, poised to enter when infected wild geese and other birds start migrating out of Russia.

The virus was detected there this month in regions as far apart as Siberia and the Caspian Sea.

When and how the virus will hit North America is unknown.

But if a global pandemic is in the cards, there is nothing anyone can do to stop it.

The loss of human life even in a mild pandemic would be devastating; anything more virulent, catastrophic. The cost of a world economy in shambles for several years can only be imagined, say analysts.

Margaret Chan, chief of influenza pandemic preparedness at the World Health Organization, no longer talks about if it is going to happen:

"The only question is: When? I don't think anybody has the answer to it. We have to be on the lookout for it any time, any day."

Specifically, scientists have to be on the lookout for human-to-human transmission of the H5N1 virus, the most lethal of the 16 known strains of bird flu. Once it occurs and is, with luck, detected, the frantic race against time will begin.

It is essential to stop the virus dead in its tracks as soon as it is picked up. Surveillance is key, says Alison Stewart, director of emergency planning at the Ontario Ministry of Health.

"If there's a pandemic, we won't be able to hold it off, so it is really important to contain it to buy time for a vaccine to be developed and distributed."

It may shock the public to learn that no vaccine for H5N1 exists, though American researchers think they found a possible one this month. Most health officials suspect the already mutating virus will mutate further before it takes off among humans. Therefore, until the exact strain is known, a demonstrably effective human vaccine can't be created.

"The U.S. has a `candidate' for a vaccine," says Dr. Paul Gully, Canada's deputy chief public health officer. "They're hedging their bets and going ahead with manufacturing it. But Canada isn't making a commitment to it."

Ottawa may obtain the "seed strain," however, to have in place if the American vaccine does prove viable.

Canada's Public Health Agency has had a contract since 2001 with ID Biochemical for it to launch into immediate vaccine production when the alarm is rung. Only problem is, it will take six weeks to three months to produce the first dose.

The only weapon during that time will be an antiviral drug, Tamiflu. Canada, like most Western nations and WHO itself, has been stockpiling it. Ottawa has bought 22.5 million doses; Ontario, 10 million.

But again, in this realm of unknowns, there is a problem. No one knows if Tamiflu, which retards the progress of ordinary human flu, will also work in the avian-human version.

"Our thinking is," says Stewart, "that even if it's not 100 per cent effective, it will provide some protection, slow down the spread in a person's system."

That doesn't mean doctors should start prescribing Tamiflu for people to hoard, as some already are. That threatens to deplete the available stock. The drug has been earmarked for the earliest patients, for health-care professionals, emergency and other vital workers, says Stewart. If it is misused by people with private caches, it could make the situation worse.

Dr. Carolyn Bennett, federal minister responsible for public health, warned this month that Tamiflu "is not for healthy Canadians to be keeping in their fridge until it is post-dated"

The people most at risk of getting the virus and potentially dying, she said, "aren't necessarily the people most able to buy the drug."

The most-at-risk are expected to be the frail elderly and the very young. But no one knows for certain. The 1918 Spanish flu epidemic that killed 40 million to 100 million people worldwide also started as a bird virus, and it targeted healthy young adults.

Either way, the delay in getting a vaccine and an effective treatment drug could endanger millions, even hundreds of millions, of people. To date, H5N1's human mortality rate is 50 per cent. No country will be safe.

If it happens.

Not everyone thinks it will. Ontario's former medical officer of health, Dr. Richard Schabas, is not convinced that H5N1 is a pandemic in waiting.

"Our science just isn't strong enough for us to know that and it's not strong enough for us to be making these kinds of alarmist predictions that we're hearing from WHO and others," he told the CBC last month.

"This is the third time WHO has told us were on the brink of an avian influenza pandemic. They said it in 1997 and they were wrong. They said it a year ago and they were wrong."

Others wonder if another "Y2K" fear-scenario is at work. In 1999, there was worldwide alarm that computer systems wouldn't be able to cope with the changeover to the new century. Billions were spent warding off an economically devastating global crash.

The crisis was averted. Many credited the pre-emptive action, but others questioned whether the threat had ever truly existed.

Could it be the same with H5N1?

No one is willing to take the chance: "If we sat back and waited for this to happen, it would be too late to tackle it," says Neil Ferguson, a leading British researcher.

His computer-modelling study, published in the journal Nature this month, found a bird flu pandemic could be controlled only if the first cluster of human-to-human infections are detected before they reach 50 cases. Within two days, quarantines, travel restrictions and medicines would have to be put in place.

Given the history of influenza pandemics — which occur about every 30 years, the last in 1968, all originating in birds — the planet is overdue, health officials say.

It is only common sense to prepare, and Canada has been meticulous. The federal plan was issued in February; Ontario's most recent plan was issued in June.

"And if the work is all for nought," says Stewart, "fabulous."

Her time won't have been wasted, she says. "Our mass immunization plan, for instance, can be used for other things, a meningitis outbreak, say."

Gully, at the national public health agency, vigorously agrees. Whatever happens with the current avian flu threat, the constantly updated federal plan will pay off in the future, he says.

"We've built on our vaccine capacity, surveillance capacity, diagnostic and communication capacities, and they're all applicable to other situations."

But if H5N1 does mutate and ignite among humans, he says, "Canada is prepared to respond."

Canada is considered by world health officials to be well prepared, a legacy of the lessons it learned during the SARS outbreak, when 438 Canadians were infected with a previously unknown virus, and 43 died.

But only about 45 countries have pandemic programs ready to launch. And in poorer parts of the world, there is little or no public health infrastructure, let alone emergency planning.

"Even if there is a vaccine," says Gully, "how does it get distributed there?"

Farmers in Southeast Asia often sleep in the same room with their otherwise free-ranging chickens and ducks. They go to markets where live poultry is slaughtered on site. Wild birds that survive an infection in their intestines can excrete the virus for at least 10 days, and the virus can remain viable for two weeks in droppings — making it easy to spread in such sites.

The Food and Agriculture Organization has said for months Southeast Asia, the virus epicentre, needs more than $100 million to build up virus-control programs. Barely 10 per cent has been raised, mainly from the U.S. and the European Union. But it's not enough and not coming through fast enough.

The flypath that migrating birds will be taking down through Europe in the weeks ahead ends in North Africa, potentially striking that trouble-plagued continent as well.

If ever a crisis called for a global response, say officials, an avian flu pandemic is it.

There is no better example of a borderless world than infectious diseases, as former Canadian foreign minister Lloyd Axworthy recently wrote: "Viruses do not observe national borders, nor do they differentiate between the wealthy and the desperately poor."

Virus pandemics least of all.

In the calm before the potential storm, the challenge is to make Canadians aware of the threat without overly alarming them or causing public panic.

And that, says Gully, "is a real thin line."

For details on Ontario's pandemic preparation plan: http://www.health.gov.on.ca/

For the Public Health Agency of Canada `s plan: http://www.phac-aspc.gc.ca/new_e.html

August 27, 2005 at 12:19 PM in Flu pandemic watch | Permalink | Top of page | Blog Home