“Why would they want to limit testing of anyone?” you’re asking yourself, reading that headline. “From day one, we’ve been told that more testing is the way to control the spread of the virus. And asymptomatic carriers are the most important people to test since they have no inkling that they’re sick and need to stay home.”

Remember, by some estimates 40 percent of all people infected with the virus have no symptoms. The only way to sniff (some of) them out is to trace the contacts of someone who’s tested positive and alert those contacts that they might be carrying the virus and need to be tested themselves. Instead the CDC has suddenly, and without explanation, declared that not everyone who’s been around an infected person necessarily needs to be tested.

Experts are stunned.

Two unexplained, inexplicable, probably indefensible changes, likely imposed on CDC's website.
* Dammit, if you come from a place with lots of Covid, quarantine for 14 days
* If you're a contact, get tested. If +, we can trace your contacts and stop chains of spread.

A sad day.

— Dr. Tom Frieden (@DrTomFrieden) August 26, 2020

Without explanation, the @CDCGov made remarkable and troubling changes to their guidelines on coronavirus testing this week.

They've gone from indicating testing for all close contacts to suggesting that testing is not necessary for close contacts of known cases. pic.twitter.com/naszBdVXTn

— Carl T. Bergstrom (@CT_Bergstrom) August 26, 2020

.⁦@CDCgov⁩ suddenly changed their criteria for #covid19 testing so that someone exposed to an infected person no longer needs testing. This makes no sense. People without symptoms account for up to 50% of transmission. We need MORE testing, not less https://t.co/KKEmGPmSDc

— Leana Wen, M.D. (@DrLeanaWen) August 25, 2020

One microbiologist told the Times she’s “concerned that the guidelines would be misinterpreted as implying that people without symptoms were unable to pass the coronavirus on to others — a falsehood that experts had been trying for months to dispel.” The last thing we want in the teeth of a winter “second wave” is for people to be less diligent about exposing others to what they might have. When the Times asked the CDC why they changed the guidance, the agency referred them to HHS. When they asked HHS, a spokesman said simply that state and local agencies could always issue their own guidance that all close contacts of infected people be tested.

Which is nice, but doesn’t explain why the feds’ policy changed. Apparently Trump’s testing czar, Brett Giroir, is going to talk about it today at some point.

There are two obvious possible reasons for the shift, one that’s bad and one that’s really, really, really bad. The bad one would be if testing in the U.S. has now slowed down to the point that the CDC feels obliged to start “rationing” tests. If local labs are effectively capped on how many tests they can perform each day, they might logically want to prioritize people who are probably infected because they’re showing symptoms over people who might or might not be infected because they seem fine. Especially with flu season looming, it’ll be important for treatment purposes to know who has the flu and who has COVID. If that’s why the guidance changed, it’s reminiscent of the feds telling Americans early on not to wear masks because they feared it would create a shortage for medical professionals. That was a type of “rationing” decision too.

The Times asked HHS about that, though, and were told that all’s well with the U.S. supply chain. No fears at the agency of any shortage. “Testing capacity has massively expanded, and we are not utilizing the full capacity that we have developed,” a spokesman said.

Which brings us to the really, really, really bad possibility. New from CNN:

A sudden change in federal guidelines on coronavirus testing came this week as a result of pressure from the upper ranks of the Trump administration, a federal health official close to the process tells CNN.

“It’s coming from the top down,” the official said of the new directive from the Centers for Disease Control and Prevention…

In a statement to CNN, HHS Assistant Secretary Brett Giroir said: “This Guidance has been updated to reflect current evidence and best public health practices, and to further emphasize using CDC-approved prevention strategies to protect yourself, your family, and the most vulnerable of all ages.”

If Giroir has scientific evidence that people without symptoms aren’t transmitting the disease it’s a verrrrrrry closely guarded secret. Literally no one else seems to have heard such a thing. To all appearances, what’s going on here is — well, let’s let this idiot tell it. A broken clock is right twice a day:

The CDC reversed its guidance to say that people in close contact with a COVID-positive person don't need to get tested.

This is not science. It’s politics. Politics that are dangerous to public health.

It's indefensible.

— Andrew Cuomo (@NYGovCuomo) August 26, 2020

The Trump administration has one COVID strategy: Denial.

If you don’t take your temperature, you don’t have a fever.

If you don’t test people for COVID, there are fewer cases.

Now they are forcing the CDC to fall in line with this head-in-the-sand strategy.

— Andrew Cuomo (@NYGovCuomo) August 26, 2020

That’s exactly what it looks like. I doubt Trump has done a single interview about COVID over the past three months that hasn’t included the inane talking point that testing is a double-edged sword. It’s a double-edged sword *to him, politically*, because each new positive test makes the government response look like that much more of a failure. But in terms of controlling the pandemic, testing is all upside. If we could test everyone and catch all the asymptomatic carriers before they left the house in the morning — and some experts think we now have the tools to do exactly that — we could crush the virus in a month. We’ll see what Giroir has to say, but scaling back testing for asymptomatic people makes much more sense politically, per Trump’s idiotic logic, than it does scientifically. This is probably the White House’s attempt to artificially deflate case counts before the election so that they can claim the pandemic is “slowing down.”

Maybe this’ll end up in tonight’s convention highlight reel explaining how a guy who’s spent five months mumbling that the virus will disappear magically is some sort of Churchill of the pandemic.

What makes this even more suspicious is that it happened just two days after another dubious political intervention by the White House into the scientific side of the federal response. I wrote about that here. On Saturday Trump accused the “deep state” at the FDA of slow-walking emergency-use authorization for convalescent plasma. Lo and behold, within 24 hours the EUA was granted. FDA chief Stephen Hahn even held a presser with Trump at which he grossly inflated the evidence that plasma would be a game-changer in terms of saving lives. He took such a beating for that from his medical colleagues that he felt compelled to issue a correction on Twitter:

I have been criticized for remarks I made Sunday night about the benefits of convalescent plasma. The criticism is entirely justified. What I should have said better is that the data show a relative risk reduction not an absolute risk reduction.

— Dr. Stephen M. Hahn (@SteveFDA) August 25, 2020

Oh well, you might say. Even if Trump did strong-arm the agency into approving plasma on the eve of the GOP convention, for his own political uses, what’s the big deal? Plasma is safe and it *might* help, right? Not so, says Jeremy Faust, a doctor in Massachusetts. The potential side effects from, say, hydroxycholoquine are less threatening than the side effects from plasma:

Plasma transfusions of all kinds have a well-documented rate of serious adverse events. These events include lung damage and even life-threatening anaphylaxis. Transfusions can cause an array of immune reactions, some welcome and some not, depending on the context. Given that covid-19 is in part driven by an autoimmune reaction to the novel coronavirus, more study is essential before doctors proceed with the plasma treatment.

Some data are already available. In a recent study of plasma in covid-19 patients, 25 serious reactions occurred among 5,000 transfusions. That’s 1 in 200. Four people died. Though it is hard to know if these deaths were directly or indirectly related to plasma, they must be taken seriously.

This is why clinical trials are important, to see if plasma works and the extent to which it has side effects. But because the FDA has now authorized it for emergency use, clinical data will be hard to come by. No one will volunteer for a trial in which they might receive a placebo when they can get actual plasma from their doctor.

To sum up, on Saturday we had Trump putting a thumb on the medical scale at the FDA for political reasons, with possibly bad results. Today we have a source within the administration telling CNN that someone at the top also put a thumb on the scale at the CDC to limit testing, something which no doctor anywhere seems to think is advisable. We all know where this is headed. Prepare for October.

Oh, and probably prepare for House hearings into the CDC’s change of guidance. I can’t imagine why Pelosi wouldn’t want to try to leverage this down the stretch to add to the Democrats’ case that the White House has completely FUBAR’d America’s management of COVID.