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.


  1. Due to breeding and other genetic manipulation factory farmed pigs tend to have weak immune systems. Farmers and visitors have to decontaminate themselves before coming into contact with the animals. It’s highly unlikely that such an environment would produce Swine Flu.

  2. It’s a good thing that evolution is just a theory.

    Otherwise I might be worried about gene mutation and the development of drug resistance.

  3. Don’t worry, JTEGNELL.

    This is micro-evolution, which is totes OK w/ God, according to my high-school Sunday School teachers.

    Just remember, “micro”. There is absolutely no way this same process could possibly be happening on a larger scale over long periods of time. Nope.

  4. TBH, the world’s overpopulated with people at the moment, and we could do with a good pandemic to ratchet down the numbers somewhat. He says, sneezing.



    Hypochondria is fun.

  6. Why is the apparent death rate due to the virus in Mexico different from the current confirmed cases in the US (40 with no deaths)?

    What are the possible contributions to death rate, and which most likely explain the discrepancy?

  7. Mark Dow, the Mexican authorities are reporting numbers based only on inpatient admissions—people sick enough to go to the hospital, which skews their fatality rate high. The US authorities are reporting based on outpatient facilities, skewing their fatality rate low.

  8. Don’t mean to come across as pious, seriously, but it would be nice in the midst of your geeking out to at least mention, and express sympathy for the friends and family of, the 150+ people who have (thus far) died from this current outbreak.

    Interesting stuff though, as usual. Keep up the largely good work, Maggie!

  9. About Israeli Deputy Health Minister Yakov Litzman’s comment about the name. If you get infected, does that make you unclean? After all the virus contains pig genes.

  10. Wild birds fly/nest/die from infections where they will.

    Pigs eat anything, including thier own fecies. Dead bird matter = more food.

    Factory farm pigs get infections (not so isolated(many hosts toghether)) so they are preventitively treated with antibotics(potential resistance/no competition).

    virus are apparently able to combine

    bird virus (B) + pig(P) virus = differnet virus BP.

    People may decontaminate coming in do they decon thier lungs coming out?

    BP + human virus = different virus BPH

  11. Daniel,

    The virus doesn’t contain pig genes, but the genes of swine-adapted flu virus. I have no idea what the does for clean or unclean, though.



    My sympathy very much is with those families. I definitely do not mean this post to suggest otherwise. I also sympathize with the fear a lot of people in the U.S. feeling about this. I just happen to find that knowledge and humor are the best medicine for fear.

  12. Aren’t the genetically altered animals normally found in factory farms much more susceptible to viruses like the flu. Isn’t that why people have to “sanitize” themselves before getting anywhere near a factory-farmed animal?

    It seems that creating animals with weaker immune systems to farm them in factories would create a scenario much more amenable to a super-virus. Just a small mistake and the you’ve got a major issue when it comes to that type of swine-farming. This American Life did a great piece on factory pig farming on their TV show. Clip here.

  13. #12: From what I’ve heard, “seen” is indeed the operative word for Mexico City air. And, yeah, that might contribute to fatalities of a disease with respiratory effects (especially when the “cytokine storm” scenario which might explain the population distribution of fatalities also has respiratory effects).

    But I’m trying not to jump to conclusions.

    Other than the observation that if this *is* a serious outbreak, it’s coming at a time when the international “immune system” may have more trouble responding.

    (Yeah, I’ve got a cough and sniffles today. Spring allergies. Not quite bad enough that I’m willing to medicate, and if that’s the price for enjoying Spring I’ll gladly pay it.)

  14. Say, if the pigs were sleeping or wallowing in muck that was contaminated with chicken feces or something.

    Aren’t bird droppings used as a part of cow and pig food? At some point they were, not sure if that practice has stopped.

  15. mad cow, new flu strains, resistant bacteria, all linked to feeding animals to animals (outside nature) and over-using drugs because factors are profitable when crowded. Buy free range eggs, insist on ethically treated meat if you eat meat and patronize the local small-holders as much as possible. Don’t buy processed foods and stay the hell out of the fast food chains.

  16. The biosurveillance blog gives a timeline where the disease may have emerged early in Veracruz where, indeed, there is a big factory farm for pigs. But they stress–and I agree–that while that could be related, it’s not proven that it is related.

  17. Viruses evolve. I was going to write ‘virii’, but that would be wrong: but not for a simple reason. See:


    Over generations, any host and its parasite will reach population stability: the host population becomes either immune or inured to the parasite.
    That in several generations people will be immune may be cold comfort for those dieing from this virus today. But that is the way that it has always been when it comes to viruses and people.
    Today the difference is that we have better – much better – medical tech to deal with these outbreaks. We have in fact eradicated a virus or two, IIRC.
    But it is yet just as it has ever been: the new viruses will keep on coming.
    As a dinosaur was once overheard to say: “You can get killed by this evolution stuff!”

  18. You are so kind, and it is so sweet
    of you to write so clearly about this current flu.

    I tend strongly to anxiety over world events, and I enjoy the internet, so you can imagine–as I believe you have–the disturbing effect of the current media coverage, not to mention the profoundly paranoid theories landing in my favorite blogs.

    Anxiety is fear and fear blocks logical processes, so I was ready to shut down my computer and skulk off to bed, in a dark mood. Luckily I checked in with boing-boing one last time.

    Logic trumps fear. Information informs logic. I will sleep lighter this night, and I thank you for that.

    Bless you for addressing these theories straight-on. Your writing, by virtue of being direct, is inspired.

    Brilliant work, in my book.

  19. Even if this isn’t directly from mass farms, they sure as hell would have contributed to it.

    21 Tak says the obvious: mad cow, resistant bacteria, over medication.

    How anyone can eat caged eggs without feeling revolting is beyond me, same goes for battery cattle in burgers (although the latter is smoothed over with a shit load of advertising and coercion.)

    It would also help if lazy GPs stopped handing out antibiotics for viral infections, and people employed common sense and alternative symptomatic relief instead of taking said anti-biotics.

  20. P.S.

    Cannabis Science Inc. Reports on Prospective Life Saving Treatments for H1N1 Swine Flu and H5N1 Bird Flu in View of the Current Global Threat

    Cannabis Science Inc., an emerging pharmaceutical cannabis company, reported today on the current state of development of its whole-cannabis lozenge in response to Homeland Security Administration Secretary Janet Napolitano’s declaration of a public health emergency to deal with the emerging Swine Flu pandemic. The Company’s non-toxic lozenge has properties that could alleviate many of the symptoms and harmful effects of the H5N1 bird flu and H1N1 swine flu viruses, and has offered its assistance to HSA today in a letter to Secretary Napolitano. The Company has offered to produce up to 1 million doses of its whole-cannabis lozenge, and provide them to HSA for distribution at cost.

    FROM: http://www.marketwatch.com/news/story/cannabis-science-inc-reports-prospective/story.aspx?guid={03D1AE62-679E-460D-988F-EE0966A80445}&dist=msr_2

  21. Cannabis Science Inc., President & CEO, Steven W. Kubby said, “We have the science and preliminary anecdotal results confirming the anti-inflammatory properties of our new lozenges and indicating they may present an effective and non-toxic treatment for minimizing the symptoms and harm from influenza infections. Our lozenges appear to down-regulate the body’s excessive inflammatory response to the influenza virus, which could reduce the deadly consequences of an infection into something that is more like a common cold. Because of my cancer and diminished auto-immune functions, even common influenza is a deadly threat, and I’ve had incredible symptomatic relief with the lozenge.”
    Dr. Robert J. Melamede, Director and Chief Science Officer, stated, “The influenza virus has a unique genetic make up that, in combination with its replicative machinery, has an extraordinary capacity to mutate. As a result, the high lethality of some strains can be attributed to the resulting adult respiratory distress syndrome (ARDS). ARDS is caused by an excessive immune inflammatory response driven by Tumor Necrosis Factor (TNF) that leads to the death of respiratory epithelial cells and resulting organ failure. Endocannabinoids are nature’s way of controlling TNF activity. Existing peer reviewed publications have shown that phytocannabinoids can prevent this cell death by mimicking the endocannabinoids that nature has selected to prevent excessive inflammatory immune responses.”

  22. Maggie,

    You are aware that according to reports from Mexico the fatalities have all been people ages 25 to 45. That should raise a big friendly HOLY CRAP situation in your Infectious Disease Dork mind…why..?

    Well as an IDD you must know the 25-to 45 characteristic is unique to one and ONLY one form of influenza, the 1918 Spanish Flu that at that time killed about 20 million people.

    Until JUST A FEW YEARS AGO when another IDD excavated victims frozen since 1918, the why of 1918 Spanish Flu’s selection of victims was a mystery. Turns out, the 1918 Spanish Flu turns a healthy immune system against itself by causing what is referred to as a Cytokine Storm which overwhelms and crashes the immune system, and has the nasty side effect of killing the host.

    Given the above well known (among IDD’s anyway) information the next logical question should be, how did the relevant genes of the 1918 influenza get into THIS one, given that the above behavior has NOT been seen since 1918…?

  23. You need to consider, very carefully, the source of the “crisis”.

    First, Napolitano has a history of “taking control” when confronted with a very public situation. As AZ governor in 2004, she prevented SWAT team members from storming a prison hostage situation for 15 days ( http://www.foxnews.com/story/0,2933,110108,00.html ). In 2003, she ordered fuel trucks to carry gas from Tucson to Phoenix to work around a pipeline break — too bad there were no trucks left to deliver gas to the stations! ( http://www.azcentral.com/business/articles/2008/06/18/20080618biz-pipeline0619side-ON.html ).

    Lately, Baxter accidently dropped some bird flu into swedish vaccines ( http://www.torontosun.com/news/canada/2009/02/27/8560781.html ).

    The WH to Big Pharma connection has happened before: http://www.defenselink.mil/specials/secdef_histories/bios/rumsfeld.htm.

    Finally, compare these few tragic deaths with historical numbers: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5715a4.htm. Figure 4 at the bottom, indicates 6-8% (or more) of ALL deaths 2003-2008 are due to influenza and pneumonia.

  24. Maggie,

    Thank you for all of the detailed information
    explained in a scientific manner. I admit I
    will refer to it often, and read it more than

    All recent references to stop the person-to-person
    spread of the virus have been from the potential
    carrier/holder of the flu virus.

    Please tell me about the conduct of the potential reciepient/victim of the flu virus while in public. Can the flu virus survive outside the
    human body for any length of time? Can it survive on money (coins/bills)? On a door handle? On hot or cold food handled (sneezed on)
    by a carrier/holder? Can the virus survive indoors suspended in the air from a cough or a sneeze?

    Thank you again for your work.

  25. There is NO VACCINE currently for the human swine flu virus. The best way to protect yourself from contracting the flu is through proper protection and sanitization. That is why we are offering an affordable way to help you and your family fight the flu. Our flu kits come with disposable surgical masks, disposable gloves, alcohol-based sanitizing wipes, and tips on flu prevention. Studies have show that wearing face masks significantly reduces the risk of contracting the flu and other illnesses. Don’t wait until it’s too late, start protecting yourself from the flu today!

    1. I’ve taken the unusual step of leaving the spam (fpkit) and redacting the URL so that we can enjoy the spectacle of a company trying to make a quick buck off of fear and death by selling $5 worth of supplies for only $29.95, that’s right folks only $29.95. Supplies limited.

  26. Before we dismiss the roll of factory farming in this outbreak, Michael Gregor, director of public health at the Humane Society in his book Bird Flu makes an interesting point about the devastating 1918 flu pandemic. At that time factory farming did not exist–there were no immunosuppressed livestock packed in tiny cages. However, there were millions of soldiers crammed into tight quarters in trenches, barracks, transport trains etc. In effect, the soldiers were the factory farm that jump started the 1918 pandemic.

    True, a deadly virus could emerge from a small farm, but I’m going to hazard a guess that our fifty year experiment with things like concentrated animal feed operations could have some unintended and unforeseen consequences such as giving novel viruses a giant petri dish in which to mutate. Of course, this is wild speculation on my part, I’m happy to admit.

    Incidentally the “H” and the “N” in H1N1 are enzymes not genes–hemagglutinin and neuraminidase.

  27. Lies all lies, everybody knows an embittered Kaiser Wilhelm, a genetist of some renown, engineered the 1919 flu pandemic because Old Man America wouldn’t give him his empire back.

  28. People who find infectious diseases interesting should read this paper.


    I think it’s kind of funny in a sad way that I haven’t read a single article to date about perspectives from actual biologist who studies evolutionary ecology. Carl Bergstrom at UW Seattle studies how epidemics occur using mathematical models.

    The “Experimental Evolutionary Ecology” class at UW Seattle is a really good class.


  29. There may still be some uncertainty if factory farming per se is the main causal factor here. But it is completely certain that MEAT EATING AND THE RELATED ANIMAL REARING is a big factor. Meat eaters don’t just harm and kill others. They also create pandemic risks for all of us. Stop harming others and create lethal risks for others — go vegan!

  30. Not as nice as using ones dietary urge as an excuse to harm animals, wreck the environment AND increase risks of a lethal flu pandemic, surely.

  31. Yeah Yakta-
    All that salmonella with peanuts, tomatoes and spinach, vegan sounds like a perfectly safe way to eat.

    It’s logically irresponsible to take the known problems of small farm practice (keeping birds and pigs together) and transpose them onto the practices of factory farms (impaired immune systems of genetically modified pigs) where it would create a problem. There’s a lot of ‘what if?’ happening there.

  32. It’s not as if commercial vegetable farms are free from environmental problems! People really need to think this stuff through.

  33. anon: The magic words in my last post where: “increase risks”. As in make a situation more risky than before. That doesn’t presuppose that before was without any risks.

    If there is a dietary alternative that, if adopted generally, would lessens the risk of a global pandemic then that is a reason to adopt and promote that alternative. In short, we here have another reason to become vegan today.

  34. Note: recent article on Wired quoting CDC or WHO profiling of the H1N1 Swine Influenza shows it has no components from Human or Avian Influenza strains. Rather it is a hybrid (reassortment) of 2 Pig Influenza strains (American and Eurasian).

    Pandemic risk in humans is greatly elevated due to the presence of an N1 gene which has never before been encountered in a Human Influenza strain and hence there’s likely to be no innate human resistance to the virus (also renders existing vaccines completely useless).

    Looks like the Human/Avian rumours are FUD or media hype (same?).

  35. is it true that the virus gets weaker in later generations with each human to human transmission? Why?

  36. Even though Nature can recreate something similary, it is good to note that we just created this something exactly like this.

    Our military scientists recreated the virulent sequences of the Spanish flu, and blended it with other flus, and it looks and acts just like this one.

    Of course, our version is safely tucked away somewhere, right?

    Supposedly they were supposed to learn a lot and make vaccines though, which was the justification for recreating such a deadly strain and experimenting. Since this is a lookalike of the military’s creation, maybe they should step forward with what they learned about it…



  37. Connection- factory farms pollute massive amounts of water. Birds live and migrate via wetlands. Birds picked up virus from massive animal waste that has polluted the wetlands.

  38. for anyone who’s interested in more info on swine flu, here’s a pretty good compilation of other FAQs from various sources on swine flu – CDC, WHO, red cross, and other info: http://www.flufaq.org

  39. To be honest, I’m scared to death of this whole Swine Flu. I have 3 kids coming back from a vacation that go to my school, and guess where they went? Bingo! Mexico, AND New York. If this flu hits my town, My huge town of maybe 600 people, we’re screwed.

  40. The USA has approximately 35,000 deaths EACH year related to NORMAL SEASONAL flu. Until swine flu reaches or surpasses those death rates can everybody please calm the F down.

    some yearly death statistics from some of the biggest killers in the US:

    Heart disease: 652,091
    Cancer: 559,312

    Just these two diseases add up to 1.2 million deaths in the us alone.

    Even if this becomes a huge pandemic (which is stil uncertain) going on past pandemic statistics this will only ever kill 2-7.4 million people (according to WHO) and that is globally.

    Add up all the people who die from cancer, heart disease and AIDS globally and this puts swine flu in perspective, yes swine flu is more scary because it seems to be able to affect anyone but people really dont need to be freaking out to this extent.

    Throughout history flu has always killed and always will. The media does not help with all this scaremongering – although I realise they are just trying to sell newspapers

  41. I would have to agree with #54’s post. The media at time is informational and sometimes just stirs the public up over things that aren’t as bad as it seems.

  42. Well, fact is that i have an homophobic neighbor whom is a physician in a public hospital nearby. He passed this 10 years disturbing me because my sexual orientation, he has been hostile in a childish annoying way, till last week that he started to walk by my windows and coughing hard against my apartment facade. So if a caught something you know whom to blame. Hes name is Filiberto Barrios. And now I am really afraid of him.

  43. It is well known that birds cary ALL influenza and believed to be the source off all influenza viruses. Also, pigs are a great transport for these viruses since they have ‘bird like’ and ‘human like’ receptors for viruses. With that, how can anyone claim a conspiracy?

  44. on the subject that some people think they are unclean if they contract the swine flu is total bogus. anyone can get any type of flu. if the virus can find a host(any human) it will attack, no matter how healthy or unhealthy and no matter how clean or unclean the person may be. however, washing your hands does help in preventing the flu. but if you are an unfortunate individual who walks behind someone with swine flu after they have sneezed or coughed and you inhale their secretion, then you will most likely get the flu.

  45. post 53
    i was terrified at first too because i have a lot of siblings and if one person at my school or even my softball team would get it so many people would be infected. we shake hands with girls from all over the state so many times after each game. plus i had the fear of the school closing down with only less than a month to go at the time and graduation, not to mention prom, on the way. what didnt help was that in the heat of all this, my chorus went to new york city. luckily no one got it and it has remained locally in most areas. the scare has gone down and summer is coming so hopefully it dies out, accourding to health officials. by the way sunlight kills the flu virus…so get plently of fresh air and wash your hands!

  46. Lies all lies, everybody knows an embittered Kaiser Wilhelm, a genetist of some renown, engineered the 1919 flu pandemic because Old Man America wouldn’t give him his empire back.

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