The Gap Between Stats and Understanding In Flu Cases

KentuckyFC writes "Bird flu gets all the headlines but ordinary flu kills several orders of magnitude more people each year and represents a significant threat to our society. The frightening thing about ordinary flu is how little we understand about how it spreads. According to a report at the physics arXiv blog, researchers trying to model this process say they still don't know some basic probabilities associated with infection (pdf, abstract). For instance, given that the disease has manifested itself clinically in an individual, what are the chances of that person dying? And if a virus can be caught from a number of different host species (as it might eventually be with bird flu) what is the probability of transmission?"

Comments

Is ordinary flu that dangerous?

[Eukariote]

but ordinary flu kills several orders of magnitude more people each year and represents a significant threat to our society.

That is a the popular perception. But it does not reflect reality: death risk from ordinary flu is actually statistically negligible. See for example this page http://thinktwice.com/cdc_2001.pdf taken from the CDC National Vital Statistics Report.

Yes, those are official statistics. Time to think twice. Yes, part of it is the good money made on all those flu shots. But that is only a small part of it. To learn more about the real reason, watch this talk by radiologist David Ayoub: http://video.google.com/videoplay?docid=6890106663412840646. Hard to believe? Verify the sources, they check out. Welcome to the real world.

Re:Is ordinary flu that dangerous?

[puck01]

First, the flu shot is not universally recommended for everyone, but is certainly available to anyone in the US. It is recommended universally in young children and very old because of their high risk as well as those with co morbid conditions such as asthma or diabetes. Health care workers should get it to reduce the risk of spreading it to high risk patients.

Second, the data you referenced only used death as an end point. That is only one of several measures. For every death, the flu causes much more morbidity which is entirely ignored by you. It causes a huge numbers of hospitalizations and ICU stays which are incredibly expensive.

Third, very little money is made in vaccines. Primary care doctors are lucky if they don't loose money on vaccines. How do I know? I am a primary care doctor and its a wash between the cost of storing and purchasing them vs how much we get paid to give them. Manufactures almost have to be begged to make vaccines because there is little financial incentive to do so. Its not uncommon to have shortages occasionally because of this.

Forth, your referencing a radiologist to talk about an infectious disease / epidemiology problem. That's usually a red flag right there. For instance I know an orthopedic surgeon that argues quite well to the uneducated how evolution is genetically impossible. He's a doctor so the uneducated take his word and believe him. Problem is, he's a idiot outside orthopedics and anyone with half an education about genetics would butcher him. Another example would be this is like getting a plumbers opinion on what type of roof to put on your house. Would you do that?

Odd

[Asmodai]

Given the fact in the Netherlands and Belgium we have http://www.degrotegriepmeting.nl/ -- an effort by some medical institutions and related institutions to monitor the migratory patterns of the flu. This is the fourth year they're monitoring. The same kind of project happens in Portugal: http://www.gripenet.pt/ Moreover there's http://www.eiss.org/ -- the European Influenza Surveillance Scheme. So if you want to talk about current statistical data, it's right there and active.

Nothing like that even enters into their paper, so pardon me for finding it a bit one-sided approach.

Flu vaccine *does* let humans adapt to nature.

[KWTm]

I have an idea. How about letting the human species's immune system continue to adapt for the flu rather than short-circuiting continued adaptation the way we are in countless other areas by creating drugs that then eventually become ineffective as the diseases evolve while human immune systems devolve?

You seem to be lumping vaccination in with other anti-infectious measures that protect you from exposure, such as sterilizing potentially infectious objects or wearing disposable gloves, but in this case your concerns are not valid.

Vaccination stimulates the human species' [no need for "s" after the apostrophe] immune system by exposing it to a safe version of the pathogen. In this way the immune system continues to "adapt for the flu", exactly as you had hoped, and in no way short-circuits the continued adaptation. As the influenza virus mutates, so does the vaccination, and each year the scientists try to figure out which strain of flu to protect against. (One year they guessed wrong, and the flu vaccine ended up next to useless as it protected against a strain of flu that only appeared in a small minority of people.)

Even for other vaccinations such as TdaP (tetanus, diphtheria, acellular pertussis) which is given only every ten years, vaccinations don't interfere with adaptation. The special case you may be thinking of is with smallpox, which was completely eradicated to the point that there is no further need for vaccination. That is not interference with adaptation, since:

• any reintroduction of smallpox is by artificial means, so in any case adaptation has nothing to do with it
• it's not worthwhile continuing to administer smallpox vaccine to let the immune system "adapt" to a potential smallpox outbreak, since the smallpox vaccine itself has a number of significant side effects. I myself was offered the smallpox vaccine shortly after the Sept11 incidents, and there was a non-negligible chance of serious illness including hospitalization and, by extension, death. (I did accept, but the threat level then decreased and it was no longer considered necessary.)
• if smallpox were to return due to natural circumstances rather than some human reintroducing the locked-up version, it would evolve from an existing virus in the wild, and vaccinations would play no part in whether the human immune system adapted
• Letting the human immune system adapt doesn't work all that well. SARS is an example of a virus for which we don't have a vaccine, and it had a mortality rate approaching 10%. That sucks. No antibiotics or other antimicrobial drugs, either, so you can't blame it on that.

I don't know if you're actually referring to the use of antibiotics, where pathogens do evolve against a fixed, unchanging drug molecule, but there are certainly advantages to having antibiotics, too, just as there are appropriate circumstances for sterilizing medical instruments or wearing disposable gloves. Nowadays we can treat skin cancer by a simple office procedure, for which the risk is negligible. Can you imagine if we didn't use sterile instruments, or if the doctor didn't wear sterile gloves, or we couldn't treat a surgical wound infection with antibiotics?

Be careful not to confuse excessive anti-exposure measures with vaccination, which takes leverages rather than suppresses the immune system.