Flu Incubators

Firstly, from what will undoubtedly go down as one of the most ironic statements New York's Democratic Senator Charles Schumer has ever publicly made, he describes pandemic preparedness spending as pork that the Senate version of the stimulus bill was well shut of:

An MSNBC reporter, whose name I apologize for not catching, reported just after 2pm ET from Mexico that analysis of a viral sample from a little boy in La Gloria, Mexico, where a widespread, unspecified respiratory illness epidemic was reported in late 2008, matches the strain showing up in the US.

The gist of the segment seemed to be that Mexican officials were coming under harsh criticism for their handling of the illness. However, while the reporters mentioned that the little boy "lived near a pig farm," and not even on one, completely glosses over the fact the 'farm' is an enormous factory confinement operation that's contaminated the entire town's water supply with hog sewage.

That's just not what most people think of when they hear 'pig farm.' Because what they should be thinking of is a small city, a slum for pigs, with extremely poor waste management.

They have around a million pigs on some of Mexico's Smithfield farms. Because a pig produces about three times as much waste per day as a human, you could be miles away and still all too near one of these things.

Pigs, themselves, can be all too near these things. As Tom Philpott reports, CAFO animals are highly immune-compromised and some of them can carry illnesses through the herd without symptoms.

Pigs left to roam in pasture may wallow in mud to cool themselves off because they can't sweat, but mud is just, you know, wet dirt. It's messy, not inherently repulsive. What pigs don't do is wallow around of their own accord in pig crap. They have to be forced to do that by farm managers who put them in cages too small to turn around in. Pigs are actually pretty clean animals, way fussier than their more adorable distant cousins, dogs and rabbits.

Infectious disease experts have been deeply concerned about factory hog farm conditions spawning a pandemic like the deadly 1918 Spanish flu for a long time now. They've considered it a question, as noted at the link, of when, not if.

At BoingBoing, Maggie Koerth-Baker talks about how chimeric viruses like human-infectious swine flu happen, which that 1918 pandemic was an example of. However, I disagree with her conclusion that small, open-air farms are more likely places for the genesis of an epidemic. More is needed for an epidemic to spread than a sick animal or person, and in the absence of an especially virulent form of disease as shown in movies, that something is usually a high concentration of new potential hosts. Even better if the hosts are in poor health or crowded conditions.

That applies whether the hosts are swine or humans. A good public health infrastructure is the best pandemic preventive, and compromised immune systems are an epidemic's best friend.

As an example, I recently talked with a friend with a hospitalized elderly relative who seems to have a flesh-eating bacterial infection. The doctor told her that around half the population are carriers, but most people can fight it off easily. It sounds scary but isn't usually a robust infectious agent. Same with systemic yeast (candidiasis) infections, which are the bane of AIDS patients and the very old, the best defense against them is to have a normally functioning immune system.

Further, a disturbing link from a commentor at that BoingBoing piece notes that earlier this year, a batch of flu vaccine was contaminated with live bird flu. As Martha Noble pointed out on the COMFOOD listserv, it's increasingly common for confinement hogs to be vaccinated against flu, and an article (firewalled, not accessible, sry) in a 2003 issue of Science aired concern that this vaccination was the cause of a sudden jump in the emergence of new strains of swine flu. (She also noted that another area of concern was the creation of transgenic pigs with more human-compatible proteins. Yikes!)

Did contaminated vaccine get sold to the veterinary pharmaceutical market this year? That's pure speculation on my part and beyond me to verify. But offhand, it seems a lot more probable than the proposition that a tiny subsistence farm is a bigger health threat than a confinement operation right near the outbreak epicenter - and it seems like a far more serious potential threat to be thinking about in future as the world pursues a model of agriculture that requires preemptive over-medication of animals that have yet to get sick.

And I don't have to go purely on instinct on this one. A 2007 Worldwatch report noted that confinement poultry farming was a far more common cause of avian flu than the backyard farms consistently blamed by international health officials:

... In Laos, 42 of the 45 outbreaks of avian flu in the spring of 2004 occurred on factory farms, and 38 were in the capital, Vientiane (the few small farms in the city where outbreaks occurred were located close to commercial operations). In Nigeria, the first cases of avian flu were found in an industrial broiler operation; it spread from that 46,000-bird farm to 30 other factory farms, then quickly to neighboring backyard flocks, forcing already-poor farmers to kill their chickens. ...

In short, it absolutely should strain credulity to suggest that a filthy confinement hog operation somehow represents a healthier, safer way to raise pigs for market.

There are all kinds of stupid things that can be done without uniformly disastrous consequences. Everyone who gets behind the wheel drunk won't kill themselves or others; but it's distressingly likely and criminally stupid to play those odds. You won't get syphilis or AIDS every time you have sex without a condom outside a long-term relationship; but it's still a dumb ass, hazardous thing to do. Every exposure to a carcinogen won't cause cancer; but it's still negligent and dangerous to intentionally proliferate them in our air, food and water. Every low-income household cut off from public health services won't suffer a serious illness or death as a result; but for those that do, it's often catastrophic.

Continuing to do stupid things because they aren't deadly every time is, well, stupid. That goes double for playing dice with public health.

Update: As fellow Change.org blogger Alanna Shaikh notes at the Global Health blog, containment doesn't work. Stopping transit between countries in this day and age is a DOA strategy and this reality requires prevention matched with robust public health responses.