imageThere is an interesting discussion on foodborne illness going on over in my raw milk post, and when looking up some stuff about that, I ran across a tidbit that reminded me of a pet peeve of mine. And that is, the widespread misunderstanding of incubation periods of bacterial infection in humans.

I am one of those people who was a victim of e. coli infection from a restaurant.

It was my workplace, and that’s an interesting story for another day. But what I learned from the experience of being grilled by the Health Department on what I’d eaten is this: they look backwards ten days to try to guess what in your dietary history might have caused the illness. (And who can remember everything they’ve eaten in the last ten days anyway?) By the time they were able to figure out our restaurant was the common denominator, every surface and food sample they tested was clear. So, the “bad batch” of whatever was long gone by the time a lot of people started showing symptoms severe enough to report.

Here’s what triggered my thoughts on this subject, a report from the CDC on foodborne illnesses from a four-year period that cited categories of incubation periods in people:

  • 3% outbreaks, the incubation period was <1 hour;
  • 30% outbreaks, 1–7 hours;
  • 20% 8–14 hours;
  • 46% >15 hours.

So this is my beef (no pun intended): all the time, I hear people say, I just barfed at 1pm and now feel terrible, so it must have been the food I ate at Sammy’s Teriyaki restaurant at noon. And poor Sammy gets unofficially blamed for causing foodborne illness, which hints at sloppy sanitation practices, and possibly steers dozens of customers away from his establishment (depending on how many people had to hear the barfer’s frank complaints…)

But we can see from the statistics (as well as just good, logical thought), that usually bacterial infection takes time to overcome your immune system to the point where you actually vomit or get serious diarrhea and other persistent symptoms. Nearly half the time, you won’t feel sick ‘til the next day. And sometimes, a week, or even ten days can go by before you become strongly symptomatic.

What I also learned from the ol’ e. coli experts is that now that I’ve been sickened by it, if I consume it again, my immune system will immediately recognize it, and send it back out the door in which it entered. A couple of times since then, I’ve eaten a burger at a BBQ, and have vomited about ten minutes later, and then felt perfectly fine. I have often wondered if this is it: my body sees even one e. coli cell, and out it goes, long before it’s had a chance to multiply. image

So, for those of us who do vomit within minutes of eating, and then have no other symptoms, this could be what’s going on: a bacteria we’ve already “seen,” even in miniscule quantities, is going to be sent packing the minute it arrives. But this is different from getting sick, as the vomiting will be instantaneous and accompany no other symptoms.

So, this is my plea: please, if you barf and then start to feel crappy, don’t blame the last guy who served you food, because  you can’t be sure he’s the culprit. It’s most likely something you ate yesterday or last Wednesday that’s causing the problem (or the flu, and not foodborne illness at all!). And because you just ate, again, and your digestive system is going haywire trying to cope with this invasion, it’s going to let you know it doesn’t want to see any more fat and protein until it can sort out what’s going wrong. [Hint from e. coli survival: live off simple sugars like Jell-O, apple juice, honey, and Popsicles until things calm down…]

Besides, you’ll never be able to figure it the root cause of your illness anyway. The only reason the Health Department can is that they get enough random reports that they can sometimes “triangulate” the common denominator when a serious outbreak of virus or bacteria occurs. And, even that doesn’t work very well, in the same report, they only figured out the etiology 32% of the time. So the bottom line is, we get foodborne illness all the time, it’s usually no big deal; but please, don’t jump to conclusions about the source and start bad-mouthing somebody’s restaurant!