Disease v. culture: Botulism in the Arctic

What if there were a food whose consumption carried a predictable risk of contracting a  fatal illness?

What if consumption of that food were so deeply embedded in a culture that there was no chance of stopping people from eating it?

That’s not a hypothetical. It’s the dilemma facing Arctic indigenous communities and health authorities over the risk of botulism from traditional foods — raw fish, whale, seal, walrus or beaver — that are “cured” by being wrapped, buried and left to rot. Alaskan Natives and Canadian First Nations members have eaten them since some lost time in their history: They’re full of minerals, vitamins and beneficial fatty acids, fresh-food nutrients that are in short supply when the world is frozen over and dark.

(I hear you gagging. So: Who eats country ham? Fish sauce? Roquefort? Products of rot, all of them. We’ll move on, shall we?)

The traditional foods aren’t fermented, strictly speaking; they’re decayed in an airless environment. That makes them friendly breeding grounds for Clostridium botulinum, the organism that produces botulism toxin. Since 1947, according to two new papers in Clinical Infectious Diseases, there have been 317 cases (159 small outbreaks) of foodborne botulism just in Alaska, as tracked by the Indian Health Service and the Alaska Division of Public Health. Out of the 317 individual cases in those records, 8.2 percent died of the paralysis of botulism poisoning.

Measured against the population, the rate of botulism in Alaska is 836 times what it is in the Lower 48. It’s such a persistent problem that the Alaska division spends scarce funds to maintain a 24-hour botulism emergency line.

There’s something interesting hidden in those numbers: Since the 1970s, the incidence of foodborne botulism has been increasing. That’s roughly coincident with the point at which Native communities began a transition that must have looked like a good idea, from

placing meat and fat tissues into skin bags … which are sewn shut and aged for weeks or months under rocks or buried under gravel

to

us(ing) either plastic bags or buckets, metal barrels, or glass containers in place of the skin pouch. (Austin and Leclair)

It turns out that something in the modern materials may have increased the possibility of C. botulinum growth: maybe the temperature differential, since they are more likely to be kept above ground; maybe the lack of contact with soil microorganisms. (A hypothesis-generating experiment showed that salmon heads kept for 17 days in a plastic container produced botulinum toxin, but salmon heads buried in a moss-lined pit did not.) One of the papers notes:

Among outbreaks for which a preservation process was described, 67% (56 of 84) were associated with storage of food in sealed plastic or glass containers, 23% (19 of 84) with storage in wood or cardboard containers, 6% (5/84) with storage in sealed metal containers, 4% (3/84) with storage in moss- or tundra-covered holes, and 1% (1/84) with storage in a sealskin bag. (Fagan et al.)

The cured foods are so intricately tied to family, tribe and place that repeated rounds of public health education haven’t dislodged them from Inuit culture. One paper notes, rather wistfully:

…an educational botulism video was distributed to all rural schools and medical facilities in Alaska, but 1 year after distribution, only 38% of Alaska Native adults had seen the video, and no behavior changes were noted that might reduce risk for botulism. (Fagan et al.)

But modernity might yet prove the cure, in two dimensions. First, the mortality rate from botulism is going down, to less than 4 percent in recent years, probably because cases are recognized and antitoxin distributed faster than in decades past. Second, and probably more important in the long run, the taste for traditional foods may be passing from Native culture. Of those 317 cases,

Overall median age was 45.0 years (range, 5–93 years). Incidence was associated with age group; age group–specific incidence was greatest among Alaska Natives aged ≥60 years. … Patient age increased from 1970–1979 (median age, 39.0 years) to 2000–2007 (median age, 49.5 years). (Fagan et al.)

If younger generations of Inuit no longer care for traditional foods, the risk of botulism will naturally diminish: no anaerobically rotted salmon heads, no Clostridium, no deaths. It ought to be something to rejoice in. I wonder though. There’s something especially compelling about foods tinged with risk; think of foraged mushrooms, or puffer fish. Inuit foods — which, I confess, I can’t quite imagine eating — must have offered deliciousness and danger, and comfort, and memory. It would have been a potent, and poignant, combination; for all its harms, a sad thing to lose.

Cites:

Austin JW and Leclair D. Botulism in the North: A Disease Without Borders. Clin Infect Dis. (2011) 52 (5): 593-594. doi: 10.1093/cid/ciq256

Fagan RP et al. Endemic Foodborne Botulism among Alaska Native Persons—Alaska, 1947–2007. Clin Infect Dis. (2011) 52 (5): 585-592. doi: 10.1093/cid/ciq240

Flickr/BenKetaro/CC

Maryn

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