A Flu Pandemic?

Pedrito writes "Scientific American is running a story in this month's issue about preparing for a flu pandemic. What this article tries to convey is that a pandemic is definitely coming. Whether it's from the H5N1 strain (which would likely cause hundreds of millions of deaths) or another strain a few years down the road. There have been 3 other flu pandemics in the past 100 years. The 1918 strain being the worst, with 40 million killed. The reason H5N1 is being followed so closely is because it's already spread to people and because it's incredibly lethal (a roughly 50% fatality rate at th moment). Even if the fatality rate dropped to 5% when and if it mutates into an easily communicable form, it would be twice as deadly as the 1918 virus."

Comments

8 click-through pages?!

[Ctrl Alt De1337]

Here is a one-page, ad-free version of the article. Seriously, when articles are formatted like this, submitters should use the "printer friendly" version of the article as the submission.

Discovery Channel

[Dreoth]

The Discovery Channel will be having a special on about this at 10:00pm EST, it was on last night and I believe it was nearly a 60% fatality rate. In Holland they had to slaughter nearly 30 million birds (mostly chickens) because the disease spread there. The most cases and deaths have been reported in Vietnam, 41 deaths out of the total of 62. You might want to watch this special, it even talks about how they found out the 1918 flu was originally a complete avian strain, much like how this new one is.

In 1918, the young and healthy were dead by night

[coyote-san]

Short subject line -- in the 1918 pandemic the young and healthy were often fine in the morning and dead by nightfall. Even in the more common situation where it took a few days to kill, it struck the young and healthy disproportionately harder.

The problem? An immune system has to be _reactive_. Your immune system has to develop sensitivity to the new virus and that takes some time. The usual flu strain isn't a problem since it's very similar to the strains we've already seen (in infection or innoculation) and our immune system can quickly respond. There's also a lot of natural selection going on over time -- a virus would rather see us miserable and contagious for a week than dead and non-contagious within a day.

But we have no natural immunity to an entirely new strain, and some can kill before our immune system can develop an effective response.

That's why older people faired better in 1918. They hadn't seen the same strain, but they had seen enough variety that they had a stronger initial response than their younger peers.

Re:In 1918, the young and healthy were dead by nig

[Guy Harris]

An immune system has to be _reactive_.

But not too reactive. The suggestion has been made that the problem isn't that our immune systems don't react to H5N1, it's that it reacts too vigorously, as per, for example, this article, Bird Flu Triggers Immune System 'Storm'.

Michael T. Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota School of Public Health is quoted in that article as saying that this might be why the young and healthy get stricken more severely (presumably he's referring to H5N1, but perhaps that happened with the 1918 flu as well):

"This is basically a cytokine storm induced by this specific virus, which then leads to respiratory distress syndrome," Osterholm said. "This also makes sense of why you tend to see a preponderance of severe illness in those who tend to be the healthiest, because the ability to increase the production of cytokines is actually higher in those who are not immune-compromised. It's more likely in those who are otherwise healthy."

Re:Sensationalist Journalism?

[temcat]

I'll worry when there's a few thousand deaths. Until then, eat healthy food, exercise and keep that immune system running. If you're not one of the typical flu victims (elderly, very young or compromised immune system from other causes), you'll have an excellent chance to shrug it off, even if it does spread.

While I'm not in a position to judge whether it's true or not, but just yesterday I read in a newspaper that H5N1 has especially high lethal rate among healthy young people, and that this is caused not by the virus itself, but by the extremely strong immune response of the organism to this virus. Basically, our immune system kills ourselves! Therefore, the stronger your immune system (above a certain threshold), the more likely that you'll die from this disease.

%50 fatal is a complete lie

[sanermind]

Ah chicken little... so convinient to completely ignore obvious scientific demonstration that it's fatality is FAR less in the actuality.

Some experts like Peter Palese of the Mount Sinai School of Medicine in New York said the H5N1 viruses are a false alarm. He notes that studies of serum collected in 1992 from people in rural China indicated that millions there had antibodies to the H5N1 strain. That means they had been infected with an H5N1 bird virus and recovered, apparently without incident.

...From this article on the international herald tribune.

Re:Sensationalist Journalism?

[surfdaddy]

Go try to find the book: "A Dancing Matrix: How Science Confronts Emerging Viruses". I read this book in the mid 90's, and it described the already overdue flu pandemic. I guarantee that if you read this you won't take influenza so lightly again.

The upshot is that flu undergoes cyclic major mutations about every 40 years. There are six mutations in the cycle. The last two major mutations were relatively benign (remember Hong Kong flu in the 70's?). The 1918 pandemic was quite lethal, and being a virus rather than a bacteria, influenza is not going to be quickly cured with antibiotics.

The bird flu virus we see today is about 50% lethal, and has even killed a high percentage of otherwise healthy individuals. I for one find this a pretty frightening scenario, let's hope that when it mutates to an easily-propagatable-between-humans form that its lethality has declined substantially. Imaging the economic effects of a spreading flu that was lethal - people would quit going to work, you could see much commerce grinding to a halt. The CDC has said we should be preparing ourselves for seeing children die, etc., at a numbers that are pretty frightening.