Meat safety problem

[Lagmonster]

Rather than populate the rant thread with a discussion on meat safety, I want to pose the following problem. Be forewarned that this is an extremely oversimplified problem; Alyrium will probably get apoplexy just looking at it. I want to see how the average consumer responds to limited information based on what they know or percieve to be true about food safety:

Joe and Bob both have a herd of food animals. They are both responsible for prevention of a disease through their herds which can infect a human who is exposed to it. The disease itself has no cure, however, the wearing of a special hat has been shown to be between 80% and 100% effective at preventing the disease. The test to see whether or not the animal actually has that specific disease can only be performed on dead animals, not live ones, because it involves removing the animal's brain and spine. The facts are as follows:

- Bob shows that he tests 100% of his herd after slaughter, but provides no statistics on how many of his animals wear the hats.
- Joe shows that he tests only 25% of his herd's carcasses, but demonstrates that 100% of his animals wear the hats.
- The tests from both Bob and Joe have shown zero instances of the disease occurring in either of their herds.

You are in the market for a steak; from a safety standpoint, who should you buy meat from, Joe or Bob? Explain why.

[Simon_Jester]

Bob's. It is possible for individual infected animals to slip through Joe's testing network. It is impossible for individual infected animals to slip through Bob's testing network.

To make a complete informed decision, though, I would need to know the false negative rate of the test Joe uses on his herd. If the false negative rate is, say, 40%, then I'd be vastly better off eating from Joe's herd.

Also, since you didn't exclude this option: I choose to wear the special hat. If someone offers me a hat that gives me 80-100% immunity to disease, I'm all for it.

[Lagmonster]

Excellent point about the hats; I sort of meant for them only to be wearable by the animals, but bonus points for being clever. It's merely a stand in for practicable preventative measures. And I did purposely give no information about the effectiveness of the test. All the consumer is meant to have is the published effectiveness rate of the prevention, the results of the testing and the rate of testing.

I admit I'm not very good at creating scenarios like this, but what I wanted to learn was whether people consider the instances of actual reported infection (by which a consumer would be comfortable eating from either herd), the ability to implement preventative measures and care (by which Joe would be better), or the rate of testing itself (for which Bob's is best).

[Simon_Jester]

Basing your consumption of reported rates is foolish, because the easiest way to drop the reported rate of any disease to zero is not to test for it at all.

Basing your consumption on the basis of preventative measures is less foolish, because there's a correlation betwen the level of preventative measures and the actual risk of getting the disease.

But basing your consumption on the combination of reported rate and testing rate is even better, because if I test all my animals, have a 0% infection rate, then my meat is guaranteed safe with no chance of infection... except, of course, for the false negative rate of the test.

Someone who is, statistically speaking, unlikely to have a disease is not as safe as a high-risk person who has been PROVEN NOT to have the disease.

[General Brock]

I buy a fish from Fred instead.

Even if I could be 100% certain that those steaks were from tested and cleared animals, I'm not taking chances with a no-cure disease based on assurances from the cattle industry. I'm sure Joe and Bob are nice guys, but so what.

If I absolutely have to choose a steak anyway, I'd choose one from the 100% tested regardless of hats, because they at least have been tested. However, there is no way I'd eat or otherwise touch the thing or allow anyone else to since there is apparently no way to detect the presence of illness in the meat itself, and slaughter can be a messy process with hundreds of cattle using the same abattoir.

[Kuroji]

Bob is the one who gets my business, in this case. I'd rather have 100% tested-and-safe meat rather than (presumably cheaper) meat that only gets partial checks. Sure, Joe will probably shut it down if any of those tests come up positive, before the meat goes out for sale... but how can we be sure that the up-to-20%-susceptible-with-hats fraction isn't the part that went under the radar?

Of course this is completely leaving aside the issue of how accurate the tests would be, or for that matter whether they're giving out accurate numbers themselves either.

[Buritot]

My choice is Bob.

As much as Joe is to be commended on taking pre-emptive measures, his focus is on his capital (animals), not the consumer's safety. As much as I love animals, if I have to decide who should live I go for me (within certain situational limitations).

If you want any more reasons (on the grounds of infected carcasses being burnt/not used):
Bobs providing 100% uninfected meat.
Joe's providing 80-100% uninfected meat, but the labelling of it can be wrong. It might in fact show an infection rate of 80% if all infected cattle had been in the test group.

In fact, Bob may be able to breed his cattle to be 100% immune to the disease.

[Alyrium Denryle]

Alyrium will probably get apoplexy just looking at it.

*Looks at the topic and immediately suffers from a hemorrhagic stroke*

While oversimplified this is actually a pretty good case study...

Realistically, I would stop eating beef.

Going only on what I see in this scenario. Bob. That is because under this scenario there is no false negative for the test. We are also assuming that there is no contamination in the slaughterhouse. That means that zero percent of the cows that make it to market are infected. While (lets assume a prevalence rate of 10% within the cow population when hats not worn) Joe's cows that make it to market have a .1x.1x.75=.75% chance of being infected.

[Knife]

Joe. Bob's steak is going to be like $50 per lbs. with all that testing, while being the most proven safe. Joe has gone through decent precautions, taken a decent sample size but not tested every thing to drive costs up. Joe represents what pretty much all our food is.

I would also be more interested in the slaughter, to make sure the cow I bought all came from the same cow and not burger from 16 different cows ground together.

[Alyrium Denryle]

Joe. Bob's steak is going to be like $50 per lbs. with all that testing, while being the most proven safe. Joe has gone through decent precautions, taken a decent sample size but not tested every thing to drive costs up. Joe represents what pretty much all our food is.

I would also be more interested in the slaughter, to make sure the cow I bought all came from the same cow and not burger from 16 different cows ground together.

Under a realistic scenario, I would also pick Joe. Where he samples 25% of his population and if he finds the disease in his stock kills everything. That is what is done with mad cow, avian flu etc.

In the scenario provided though, with a population incidence of the disease above say, 20% you start running into very significant risks of infection if you pick Joe's steak. Unfortunately the hats do not protect well enough to provide herd immunity IIRC

[Lagmonster]

Joe. Bob's steak is going to be like $50 per lbs. with all that testing, while being the most proven safe. Joe has gone through decent precautions, taken a decent sample size but not tested every thing to drive costs up. Joe represents what pretty much all our food is.

I would also be more interested in the slaughter, to make sure the cow I bought all came from the same cow and not burger from 16 different cows ground together.

Under a realistic scenario, I would also pick Joe. Where he samples 25% of his population and if he finds the disease in his stock kills everything. That is what is done with mad cow, avian flu etc.

In the scenario provided though, with a population incidence of the disease above say, 20% you start running into very significant risks of infection if you pick Joe's steak. Unfortunately the hats do not protect well enough to provide herd immunity IIRC

You're dissecting my oversimplification. Note to self: never expect gut-instinct consumer decisions on food from a biologist.

You are, however, aiming in the right direction; BSE in particular is the model here. In 2006, Japan tested every single carcass, and Europe tested the hell out of their animals as well, with the accompanying fanfare and claims of superior interest in the public good. Canada adopted the Joe method: manageable testing standards (~30,000 per year being the goal since 2006), while relying on heavy prohibitions on imported meats and the aforementioned preventative measures - the removal of skull, brain, trigeminal ganglia, eyes, tonsils, etc. from animals that are slaughtered, improvements in slaughter practices, and various feed restrictions, among other things.

[Alyrium Denryle]

You're dissecting my oversimplification. Note to self: never expect gut-instinct consumer decisions on food from a biologist.

Dude... not just a biologist, but a biologist who's work deals explicitly with predation risk. Emphasis on the risk. Probability to be attacked by a predator, probability of escape, predator mitigation strategies etc.

Lot of parallels to my actual research with this stuff. It deals with the converse... foraging, and there are risks involved there too

In other words, when it comes to food I do not do gut instinct. At least not mine.