They're not purple soot sprites: This is a transmission electron micrograph (TEM) of norovirus virions. Welcome to gastroenteritis, population: you. (CDC/ Charles D. Humphrey)

Here’s a nifty number, unless you hate crowds: The projected attendance at Dragon*Con 2010 is 40,000 people. And here are some less nifty numbers, unless you’re into studying common pathogens: You can wind up with vomiting, diarrhea and cramps if fewer than 10 norovirus particles make it into your body, and you can get a cold off of one infectious rhinovirus virion.

That kind of puts con crud into perspective. Lots of people means lots of potential pathogens. Add that to close quarters and four days or so of exposure and you have an infectious disease paradise

After a significant H1N1 flu outbreak at PAX 2009, a few well-known geek celebrities have made a rule of not touching people at conventions, and some have gotten flack for it. It’s a somewhat drastic measure, but if I were famous I’d probably do the same thing. Famous people have lots of hands to shake; I want to shake the hand of comparatively few famous people. So here are some less draconian steps for the non-famous of us:

1. Wash your hands. A lot. Especially before you eat, after you use the bathroom, after shaking hands, after you’ve touched anything … questionable … and after you’ve pawed through all those classic comics in the dealers’ room. Spend enough time washing — it takes at least 20 seconds to get enough of the pathogens off of your skin to prevent illness. Sing the alphabet song through twice. Or the first verse to Jonathan Coulton’s “Still Alive,” up to “Except the ones who are dead.” Which, at that point, should be the germs.
2. Also carry and use hand sanitizer. It’s not a substitute for hand washing since you can’t really sanitize dirt with it, but it’s better than nothing in a pinch.  You probably need to use more than you typically do — enough to really wet your hands thoroughly — and you need to rub your hands together for at least 25 seconds. Sing “Still Alive” again, or the first verse of “I Feel Fantastic” (at album speed, not live show speed).
3. Most of the things that can make you sick are going to get into your body through your eyes, nose or mouth, so keep your hands away from your face.  This has the added bonus of protecting things like makeup and latex prosthetics from smudging and shifting so you don’t wind up looking like a “True Blood” vampire after a crying jag.
4. Cover your mouth when you cough or sneeze — either with a tissue you can throw away or with the inside of your elbow so you don’t spread germs from your hands to things other people are going to touch.
5. Try to get some exercise every day, sleep for eight hours a night, eat a balanced diet, avoid junk food, and keep drinking and other vices to a minimum! (Stop laughing.)
6. There’s no question that for a nonzero number of people, a con is for hookups. Exercise caution and appropriate prophylaxis.  Do not be undone by the beer goggle effect.
7. Quarantine yourself if you’re sick. Yes, you can transmit illnesses before you’re symptomatic, and yes, Dragon*Con only happens once a year. But somebody, somewhere was Patient Zero in that massive PAX H1N1 outbreak, which is not a bragging right anybody really wants to have. At least anybody who isn’t a sociopath.

Con crud: Have you had it?

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