Dr. Deborah Birx was on CNN yesterday, and along with her dubious defense of Disinfectant Donnie’s musings about ‘cleaning out’ the body, she talked about the future of Covid-19 testing.
"For every lab, though, they're now -- they now have six or seven platforms that they have to integrate and utilize. And labs are learning now how to bring all of those platforms up to hopefully double and increase our testing ability across the country, and to really align the needs," Birx told CNN's Jake Tapper. "There's capacity, that tests are not being run. And I think ensuring that they have the swabs, ensuring that they have the tubes to transport the swabs in, and then ensuring that all the laboratory platforms are up and running, and that's the information we gave to the governors," she said. Birx added that "there's over 5,000 pieces of equipment in the United States that can run these tests and we're very excited to see all of those utilized."
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‘Hopefully double and increase’…. we’re running about 250,000 tests per day, so doubling and more would mean getting to 500,000 and then some incremental increases… still clearly insufficient.
When the list of ‘over 5,000 locations’ was first waved around by Dear Leader, I wrote 2 diaries, here and here, detailing why this claim that all our problems were solved was just another fever dream.
It’s impossible to be exact without having the full list of those 5,000 machines, but since most of them are small and slow, all the machines in all the labs in the USA put together probably couldn’t crank out more than 600,000 tests per day… and that’s a pretty optimistic estimate.
Since experts are predicting that we need to run somewhere between 2,000,000 and 20,000,000 tests per day to even start getting to something like a ‘new normal’ (whatever that is), we’re just not going to get there with the current PCR testing technology. Back to Dr. Birx…
Unlike most current tests, which are called PCR tests, antigen tests look for characteristic structures from a virus. These structures, often on the virus' surface, help trigger an immune response."I know corporations and diagnostics are working on that now. We have to have a breakthrough," Birx told NBC's Chuck Todd on Sunday. Current technology, she suggested, would only be sufficient for so long. "This RNA testing will carry us, certainly, through the spring and summer, but we need to have a huge technology breakthrough, and we're working on that at the same time," she said. Those advances would allow us to "screen large numbers of individuals quickly," Birx added.
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OK, then, what’s the problem? We have huge technology breakthroughs all the time.
Why not? An antigen test for a bacterial disease like strep works well. But respiratory viruses like coronavirus are a whole other game. The home of a respiratory illness is in the respiratory system, so ideally you want to use a nasal swab to collect samples deep in the nasal cavity. But the presence of the virus in this area varies from person to person. For example, the antigen test for influenza has a decent sensitivity of about 70 to 80% when run properly on a good nasal swab—but only for children, because the quantity of the virus in children is typically much higher than in adults. When you use the same influenza antigen tests on adults, the sensitivity drops to less than 50%. And this is something observed across the board for respiratory viruses. In a PCR test, the viral genetic material is amplified so that it’s easier to identify signs of covid-19. There’s no amplification of viral proteins in an antigen test. Either the test detects them in the sample or it doesn’t.
Companies like E25Bio and OraSure have made successful tests for other diseases, but not for respiratory viruses, and Wells is very skeptical they’ve solved the biological and technological issues that hold these tests back. “I would love to be wrong,” he says. “But if I’m betting, the covid-19 virus is not going to be any different from the other viruses. It’s not a new biology or a new chemistry.” Antigen testing groups that are claiming sensitivities above 90% are basing that on laboratory samples. They are still waiting for validation tests on actual patient samples, which may be much less accurate.
So that’s the huge technology breakthrough that Dr. Birx was referring to — adapting antigen testing for use with respiratory viruses, which looks like a serious challenge… maybe not a moon-shot, but not a quick fix, either.
Here’s more information on E25Bio and its antigen test:
E25Bio’s rapid diagnostic test resembles an over-the-counter pregnancy test and provides visual results within 15 minutes by detecting the presence of the virus in the patient sample. As a point of comparison, hospitals across the country are currently using polymerase chain reaction (PCR)-based tests that typically take 24 hours or more in some cases to provide results. Given the exponential rate of spread of the virus, there is a critical need to deploy fast, reliable, affordable, and easy-to-use point-of-care tests in order to flatten the curve by quickly detecting and isolating patients who need immediate care. Having identified a Massachusetts-based manufacturing partner, the startup is in the process of obtaining clearance under FDA’s Emergency Use Authorization model.
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And there we see another problem: the FDA has essentially given up even trying to do its job, which is testing and approving medications and diagnostic tests before they are put on the market. An Emergency Use Authorization (EUA) from the FDA merely requires that the company developing the test checks a box stating that it has validated that the test works as it should. No standards, no accuracy requirements, no minimum specificity limits, no formal testing protocols — just the company saying ‘it works’. What could possibly go wrong?
So here we are, as confirmed by Dr. Birx: our current testing regime is nowhere near what we need, and now we’re hoping on a ‘huge technological breakthrough’.
Thank goodness that our entire country’s leadership, from the president on down through all the state governors, are united in their consensus that we need to keep everything shut down until new cases and deaths decrease to levels we can deal with and we have enough testing to get a handle on the spread of the disease.
Yeah, that was sarcasm.
Cheers.