

Why CDC says this year's flu season is "very sobering" - cwan
http://scienceblogs.com/effectmeasure/2009/10/why_cdc_says_this_years_flu_se.php?utm_source=nytwidget

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idlewords
The real reason epidemiologists are concerned about swine flu is its novelty.
It's possible that it's very far away in phase space from a truly killer flu,
but it's also possible that it's only a couple of mutations away from becoming
deadly.

Since flu mutates fast, any truly novel strain that reaches pandemic status
represents a serious threat. Fortunately this kind of leap only happens every
few decades; unfortunately, we have no defense against it.

An interesting article covering this point:
[http://scienceblogs.com/effectmeasure/2009/04/swine_flu_i_be...](http://scienceblogs.com/effectmeasure/2009/04/swine_flu_i_beat_a_dead_horse.php)

~~~
sketerpot
I would love to see the day when we can calculate the Hamming distance to
deadliness for all the common flu strains, so we'll know exactly how alarmed
we should be each year.

~~~
jcl
Of course, that means we'd be living in a future where the DNA sequence for
the deadliest possible flu strain is computable. We'd have a pretty good
reason to be alarmed every single day.

~~~
Semiapies
Why? That'd be the first thing we'd vaccinate for, given that capability.

~~~
jcl
Once you vaccinate for it, it becomes less deadly. Which means there is a new
(computable) "most deadly" flu. And, presumably, there is an upper limit to
the number of strains our immune systems can remember and defend against.

~~~
Semiapies
Perhaps; on the other hand, once we have the capability to do something as
hard as compute most-deadly-flu, we'll almost necessarily have the
immunological understanding to vaccinate against very broad categories of
diseases, not merely individual strains.

------
andreyf
Seems to agree with Google's estimates, although they don't break things up by
age: <http://www.google.org/flutrends/>

Before everyone panics, however, I'm pretty sure this kind of statistic is
self-reinforcing: if reports of flu are higher, and those reports are
broadcast, people are more likely to go to the hospital when they exhibit flu
symptoms, making the flu counts higher yet.

The media coverage of the swine flu might very well have set off this cycle.

Addendum: it isn't necessarily a bad thing - according to this hypothesis, if
people who would have died of the flu this year are more likely to go to the
hospital, and so _less_ people should die. Or it might be that those who die
of flu have reasons for not going to the hospital unaffected by media.

~~~
dpcan
Well, that's just it isn't it. More people with flu symptoms are going to the
hospital and being diagnosed with flu, whereas in the past, they stayed home
and got better.

All because of bullshit reporting like this:

[http://www.krem.com/topstories/stories/krem2-102009-flu-
deat...](http://www.krem.com/topstories/stories/krem2-102009-flu-
death.237ef85fb.html)

A women felt ill. Then felt a little better. Then got ill again within a few
days and died in the Hospital overnight.

Without even CONFIRMING that it was Swine Flu, they are reporting it like it
is, and they are scaring up everyone in town to think that if they have a
tickle in their throat they are going to die in 3 days.

~~~
axod
In the UK, you're told specifically not to bother going to doctor/hospital etc
if you have swine flu (Unless you have complications/other conditions etc).

We had it in July or so. It was kinda like a normal flu :/

The media loves to scare the hell out of everyone - gets them to buy stuff.
Sad, but I can't see that ever changing.

~~~
Anon84
_We had it in July or so. It was kinda like a normal flu :/_

You might want to take a look at the bottom right panel of Fig 2:
<http://www.biomedcentral.com/1741-7015/7/45> ;)

~~~
axod
Yup that's what they thought would happen. They were raving in the papers that
everyone would have it in sept/oct, schools wouldn't open, etc.

What actually happened was that most people got it over the summer holidays
afaik.

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tlb
Most viruses just make you sick. It's at least possible that a virus could
evolve where the RNA coded for THC or alcohol. Or some other chemical that
affects mood. That would make for an entertaining, non-sobering flu season.
Can someone estimate the probability of something like that happening
spontaneously?

~~~
bd
_"Can someone estimate the probability of something like that happening
spontaneously?"_

With a lot of handwaving ...

\----

If everything goes perfectly (each random mutation flips the right
nucleotide), you would need at least 77.5 years to get alcohol-production-
capable RNA in influenza virus solely by spontaneous mutations.

\----

Details:

Checking one possible ethanol fermentation pathway [1]: at minimum you would
need to synthesize two enzymes - pyruvate decarboxylase (1,691 base pairs [2])
and alcohol dehydrogenase (1,046 base pairs [3]).

Influenza A has 13,558 base pairs [4] and mutates at about 0.0026 mutations
per site per year [5] (so you get about 35 changed nucleotides per year).

Putting it all together gives about 77.5 years.

    
    
      (1691+1046)/(13588*0.0026) = 77.47
    

\----

[1] [http://biocyc.org/META/NEW-
IMAGE?type=PATHWAY&object=PWY...](http://biocyc.org/META/NEW-
IMAGE?type=PATHWAY&object=PWY-5486)

[2] <http://www.ncbi.nlm.nih.gov/gene/850733>

[3] <http://www.ncbi.nlm.nih.gov/gene/854068>

[4] <http://en.wikipedia.org/wiki/Influenza_A_virus>

[5] <http://jvi.asm.org/cgi/content/full/80/7/3675>

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arfrank
A quick link to the PDF in the document:
[http://www.scribd.com/full/21397763?access_key=key-2hixg48wt...](http://www.scribd.com/full/21397763?access_key=key-2hixg48wtpqgacm0ep6l)

It has a bunch of graphs that the CDC put together.

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RevRal
"Mutating virus" just sounds bad.

