Mass testing, even testing that's mostly at a stage unlikely to detect anything, and only occasionally on less-typical older animals, will provide new useful info. Waiting to test until an a old symptomatic cow "most likely to have the disease" shows up is closing the barn door after the mad cows have already escaped.

The USDA's logic is dangerous like the bureaucratic rationing of COVID tests, early on. At crucial times in early 2020, no matter how suspicious a case/death, and how well it fit COVID symptoms, if the patient hadn't returned from Wuhan in the last few weeks, a test was prohibited. That's a "we don't want to know" policy.

What useful information does it provide? Is there any evidence that testing can detect BSE before symptoms appear? Japan had tested clinically healthy cows until 2017, when they decided to limit testing to symptomatic cows.[0]

> Waiting to test until an a old symptomatic cow "most likely to have the disease" shows up is closing the barn door after the mad cows have already escaped.

Obviously it would be ideal to detect BSE in cows that are younger and not yet symptomatic. But if there's no evidence that this can be done, testing provides a false assurance of safety. Testing older, symptomatic cows will at least give an estimate as to the prevalence of BSE and an indication as to whether safety measures are working.

It's much ado about nothing, anyway, since the US has only ever had four cases of vJCD from BSE, and in each case the individual had spent large amounts of time in countries known for having tainted beef. Perhaps dementia cases are misdiagnosed, but if there were a large danger of BSE/vCJD, one would expect to see those symptoms in a great deal of younger people.

[0]: https://www.fas.usda.gov/data/japan-japan-lift-age-based-bse...

The potential for surprise & early detection.

As your quote noted, most cows are slaughtered earlier, so generations could be infected without any detection. If you only test 5yo symptomatic cows, you can never find an outbreak until it's too late, or anything that contradicts the breezy reassurances of the industry-captured USDA.

Again, it's like when the CDC & Fauci were assuring people that there was no significant community COVID spread, when they were also blocking any testing that could detect such spread, by limiting tests only to those that fit their preconceived notion ("only recent returnees from Wuhan").

How much, if any, random surveillance of older asymptomatic cows happens that gives you such confidence in the current testing?

How many meat cows live long enough to get a good read on the symptomatic rate?

Are you sure early mild symptoms of ill health might not just get a cow culled before enough symptoms-to-test arrive, by ranchers who, like the USDA, "would rather not know"?

Your last paragraph seems to reduce to, "we'll know if there's a lot of it, if and when there are a lot of young people with suspicious BSE".

We should aspire to use something other than our young people for early detection. Or at least not block those who want to try it.

They couldn't be detected by those tests anyway if they don't have symptoms, or at least not until shortly before symptoms become apparent.

> Again, it's like when the CDC & Fauci were assuring people that there was no significant community COVID spread when they were also blocking any testing that could detect such spread, by limiting tests only to those that fit their preconceived notion ("only recent returnees from Wuhan").

There are a number of differences here. Most importantly COVID tests can detect if you have COVID even when asymptomatic, but BSE tests cannot detect BSE before it is symptomatic.

> How much, if any, random surveillance of older asymptomatic cows happens that gives you such confidence in the current testing? How many meat cows live long enough to get a good read? Are you sure mild symptoms of ill health might not just get them culled before enough symptoms-to-test by ranchers who, like the USDA, "would rather not know"?

> Your last paragraph seems to reduce to, "we'll only know if there's a lot of it if and when there are a lot of young people with BSE".

First, the testing is of symptomatic cows, not asymptomatic cows, and it is deliberately not a random sample, but a sample of the population that is most likely to have it.

Second, my point is that the lack of any cases of young people with vCJD in the US, let alone widespread cases, indicates that it simply isn't the case that we have some phantom population of cows with BSE that are being let through by the USDA.

> Or at least not block those who want to try it.

I agree the USDA shouldn't block it. However, it isn't unreasonable to prohibit marketing based on the use of such tests if they give an unwarranted impression of safety; allowing that would be misleading advertising. When Creekstone applied to do testing, it was precisely for this reason that they applied, and for this reason they were denied.

Your topmost comment mentioned tests can detect BSE "2-3 months before" symptoms. That'd catch more than waiting for symptoms - especially if done broadly! Waiting for symptoms, when the window-of-detection is so small & so late-in-life, & most cows slaughtered young, seems designed for entities that "would rather not know".

> Most importantly COVID tests can detect if you have COVID even when asymptomatic, but BSE tests cannot detect BSE before it is symptomatic.

This contradicts the explicit 2-3 months before symptoms claim you made previously. Also, being less restrictive about testing could create the necessary market for more sensitive tests. If a cow can have it its full life, but it only reaches detectable levels after years, maybe tests can eventually detect the early presence.

> First, the testing is of symptomatic cows, not asymptomatic cows, and it is deliberately not a random sample, but a sample of the population that is most likely to have it.

Exactly! There's zero testing where it wouldn't already be suspected. So no chance to discover a problem early, or challenge the assumptions limiting testing.

> Second, my point is that the lack of any cases of young people with vCJD in the US, let alone widespread cases, indicates that it simply isn't the case that we have some phantom population of cows with BSE that are being let through by the USDA.

Indeed, but the correlate of that is that the regime you're advocating can thus only detect a problem after a bunch of atypical, or weven "widespread", cases are noticed. That's the signal you're waiting for, before testing more.

That approach sucked for COVID, it'll suck for BSE.

I really try to stay away from politics, but sounds as something made by some bribed political appointment.

I'm not an expert on testing for prions, but it doesn't surprise me that the test isn't good enough to pronounce an animal disease-free. And if that's correct, it's very much their purview to make it clear that advertising it as disease-free would be false.

Most of the work at US agencies is done by career employees who are largely insulated from changes at the top. Politics certainly happens, but rarely at the level of individual decisions like this.

Such agencies certainly aren't immune to regulatory capture, and it's conceivable that it's the case here. The scientists and bureaucrats who wrote that have likely worked with the cattle industry their whole careers, and have many personal contacts. Same for their bosses.

But this memo turns on a specific technical point. If the tests aren't good enough, then they're not good enough. It wouldn't take regulatory capture for them to reach that conclusion, and this memo is exactly how they'd say it. It's also what it could sound like if they were being influenced by industry, but I'd say that the burden of proof is on somebody making that claim.

If 3,4 million new cars are sold in USA then probably 99% are generally ok. Because in current world generally most things are ok by default (custom software might be different, but off the shelf software generally works).

But if you would be unlucky 1% where nobody checked the breaks... this would be 34 yhousand cars.

And there is much more cattle raised and consumed so checking everything makes sense.

Not checking anything because 99% will be ok is a pseudoscientific argument.

This isn't what the argument against testing every cow is about. It is really 'You can't test every car's brakes with a test that will say the car's brakes are OK even if those brakes are bad'. If a food product had a toxic ingredient, do you think it's appropriate for a company to run a test that can detect it, say, 50% of the time, and say their product is xyz-toxin-free? What if the test is only effective 10% of the time? 1%?

The USDA didn't decide not to perform no tests for BSE tests at all. They decided to perform tests specifically for those cases where, if the cow had BSE, the test could actually catch it. Again, I don't entirely agree with the USDA's approach, but it isn't unreasonable.