Tuesday, April 28, 2009

Australia Has Been Invaded

By Darryl Mason

Today, there is a new, triple influenza virus, of which little is known, circulating in Australia. Just as we move into winter and closer to the peak of Australia's flu season, another flu virus has come to join the annual influenza party inside us.

So how do you know if the influenza you have is the new one, or just one of the old ones? You don't, until you're tested. Apparently, the symptoms of infection from the strange new influenza virus, and the human flu viruses of recent years, are all but exactly the same. You get aches, you feel like puking, you can't hold down food, your nose runs, you sneeze, you spend more time on, or with your head in, the toilet than you do in bed.

What is known is that the new influenza virus is an unnatural, never-before-seen brew of genes from human influenza, avian influenza and swine influenza. Human to human transmission of the new triple influenza virus appears to be happening faster, and easier, than with bird flu outbreaks in Indonesia in 2007 (our most recent brush with pandemic influenza), though it doesn't yet appear to be as fatal, as bird flu proved to be, for those who become infected.

However, this effect of fast, widespread infection, but lower overall mortality, may make the possibility of a pandemic more, not less, likely.

It is not in the interest of a virus to kill its host quickly, the virus wants to spread, to invade other cells, to find new hosts, to mix with other genes, to grow, to super-strength its rapid evolution, to perfect itself, to move on.

Even though fewer who are infected may die from the virus, the death toll is likely to be higher, as a prolonged human incubation, with few or no signs of possible infection for days, or a week, will allow the virus to spread itself farther through the human population.

If the pandemic mortality rate for human infections by the Human-Bird-Pig Flu virus is only 1-2%, the death toll for a hundred thousand Australians sickened by the virus would be a few thousand. But if the new virus is highly infectious, kills fewer of those it infects initially, but spreads fast across the population, we may see millions catch the virus over the longer exposure time, with tens of thousands killed.

If we are heading into a pandemic, it is likely it will unfold over many months, or more than a year. New influenza viruses rarely appear, and then quickly disappear again. They hang around, they spread and mutate, searching for the best combination of genes from its hosts to evolve further, they come and go from our bodies like once-a-year hotel guests.

The closest influenza virus that some virologists believe this new virus will be eventually matched to is the 'Spanish Flu' pandemic influenza of 1918, which killed its tens of millions of victims around the world in waves, a few months apart, each wave of the pandemic lasting two to five, or more, weeks. This kept the 'Spanish Flu' virus in circulation across the planet for more than 14 months, or longer. The longer it survived, the more it infected, and the more people it eventually killed.

There will be a human influenza pandemic, eventually, most influenza experts certainly agree on that. "Inevitable" is the word they use. And many are nervous today, about what may unfold in the months ahead if the Human-Bird-Pig Flu virus does indeed turn into a pandemic.

The best case scenario is that this will turn out to be only another pandemic close call, a brush with a virus that could kill tens of millions, but does not. This time.

Either way, the Federal Government will get to live-test its pandemic response plan.

That pandemic response plan is now getting underway. Quarantine centres near major Australian airports, including Sydney and Brisbane, are preparing to begin isolating Australians and foreigners who are showing visible signs of influenza infection as they step off planes from the United States.

There may be ugly scenes at our airports if passengers are falsely identified by others during flights to Australia as showing signs of flu infection when they're not sick, or don't believe they're sick. If one member of a family of travelers shows enough signs of infection to convince a Qantas captain to radio ahead that they have "a hot one", the whole family is expected to be placed in quarantine.

The almost incomprehensible option of completely shutting down the airports to all arrivals, including Australians returning home, is also part of the official government pandemic response plan, though no doubt the government will wait until deaths from the new virus occur here before it takes any steps that radical.

Can you imagine the fury and chaos if thousands of Australians living and holidaying internationally were told they can't come back to their own country for the time being? Particularly if there was a deadly pandemic breaking out in the rest of the world, and the growing death tolls terrified them about the fates of their friends and families?

There'd be new waves of boat people, but they'd be Australians desperately trying to get back home through closed borders.

UPDATE : As of May 7, there have been no confirmed cases of H1N1 infection in Australia.