Swine Flu Fun Facts

Maggie Koerth-Baker is a guest blogger on Boing Boing. A freelance science and health journalist, Maggie lives in Minneapolis, brain dumps on Twitter, and writes quite often for mental_floss magazine.

You should probably know that I'm a giant infectious disease dork. Viruses are right up there with subways, as far as I am concerned. In fact, the main reason I'm writing this right now and not, say, working on a Ph.D. somewhere, is because nature saw fit to gift me with the math skills of a brain-damaged baboon. Do not pass calculus. Go directly to journalism school.

Naturally, then, I have spent the weekend geeking the hell out over this whole looming-threat-to-civilization thing. In between obsessive reading and some interviews conducted for National Geographic News, I've come up with a few tidbits of information I thought y'all might find as fascinating as I did.

Why It's Called "Swine Flu"
By now, you've probably heard about the fact that this particular strain is basically a genetic tossed salad of pig, bird and human flu virus. So why is the pig part getting all the "glory"? According to Andrew Pekosz, over at the Johns Hopkins School of Public Health, it's because the two genes most important to determining whether humans are immune and what level of protection they have (that'd be the "H" and the "N" in H1N1, by the way) happen to be ones that came from porcine flu strains. We call this chimera "Swine Flu" because that's where it got the genes that really matter most to our health.

On a related note, the AP is reporting that an Israeli Deputy Health Minister is vehemently opposed to the name, because he finds the pig reference religiously offensive. Yeah,I dunno, either.

Swine Flu Was Genetically Manipulated to Target Conspiracy Theorists
It's true: If you own a tin hat, you're ten times more likely to contract the virus. Seriously, though, could the Internets please stop forwarding those increasingly out-of-context videos of Dallas County medical director John Carlo? In some recent interviews, Carlo referred somewhat clunkily to culturing samples of H1N1 in the laboratory. This quote is now being used as "evidence" in a delightful meme claiming that H1N1 is a man-made virus, wholly created in the laboratory. As Carlo himself has pointed out, that is not remotely the case. In reality, those video quotes are actually Carlo referring to the common practice of taking samples of a virus and growing it in the lab until you get enough of the virus that you can analyze the thing. That's how researchers learn what makes a specific virus unique and how they figure out ways to combat it. Scientists studying cultured samples of a naturally-occurring virus =/= evil plot to create a man-made super-virus. Please, tell your friends.

How Nature Makes a Chimeric Virus
As frustrating as that whole Carlo debacle is to me, I can understand where some of the confusion is coming from. Everywhere, you're reading that H1N1 swine flu contains genes from human, avian and swine flu viruses and, for most people, the imagination immediately jumps to genetic engineering. But, let me assure you, nature can do this perfectly well on its own. No human tampering required.

It works like this. Flu viruses have eight genes, each of which is on a separate piece of RNA and, each of which replicates independently of the others. Multiple types of flu virus can infect the same cell. If a cell is infected with two or three different viruses, genes from the "parent" generation can easily get shuffled around and randomly repackaged into chimeric "offspring". For a visual, think about taking two shakers of dice, tossing the dice out on the table, swirling them around and splitting them back up again into the shakers. Chances are, some of the dice that were originally in shaker 1 are now in shaker 2, and vice versa. And that's basically a simplified version of what's going on with flu virus genes when they create something like H1N1.

Some Thoughts on Factory Farming
So I know that Grist, and a couple of other places, are promoting the theory that the genesis of H1N1 swine flu can be tied directly to factory farming practices. I'm no fan of factory farming, and it definitely has some associated public health dangers, but I'm not yet convinced that this one of them.

First, according to the experts I've spoken to, nobody currently knows specifically where H1N1 swine flu comes from. In fact, the information we're getting out of Mexico seems to have a lot of holes in it, to the point that (as of my writing this) nobody even knows how many supposed swine flu cases/deaths are actually caused by swine flu or what percentage of people infected with swine flu are dying in that country. As Pekosz told me, there's no evidence one way or the other.

Second, while past pandemic viruses have had connections to farming, they haven't necessarily been connections to factory farming; but rather small-scale (and, particularly, subsistence level) farming, where animals of several species share close quarters. This is important for the H1N1 swine flu. Pigs seem to provide a particularly good environment for flu viruses to get their gene-reassorting watusi on. But to get that pig/avian/human mix, the most likely candidate would be a pig who'd had close contact with both people and poultry. As I understand it, it's less likely that a human who works with pigs and chickens separately could pass the avian virus to a pig. And, factory farms, which tend to be single-species outfits, aren't really great places for pigs and chickens to interact.

Now, I can see some ways around that. Say, if the pigs were sleeping or wallowing in muck that was contaminated with chicken feces or something. I could also be interpreting the facts incorrectly here. But from what I've read, and from the researchers I've spoken with, it seems more likely that H1N1 would have been created in the communal barn of a small farm, than in a giant hog-only factory farm shed.

I'm going to be enthralled with the swine flu story for weeks, I'd imagine. So if you've got questions about it, or rumors you'd like to hear the facts behind, I'm more than happy to put my nose to the research wheel on them. Best thing is to email, though.