The CDC Screwup, Explained Very Briefly

Test results from a PCR assay of a herpes virus.Mohammad Hadi Sadeghian et al., Open access

Let our journalists help you make sense of the noise: Subscribe to the Mother Jones Daily newsletter and get a recap of news that matters.

I finally got curious about how and why the CDC managed to botch COVID-19 testing so badly. The answer isn’t complicated, but I still have questions.

The whole story is pretty short. The CDC test is a PCR¹ assay, a well-known and fairly easy diagnostic to perform. However, to make sure it isn’t simply flagging everything as the target virus, PCR tests always include an unrelated sample of DNA as one of the reagents. If everything is working properly, the unrelated sample should never produce a positive response. Unfortunately, the CDC bit off more than it could chew and created a test for multiple viruses—and then botched the reagents for one of them. The result was lots of false positives, which in turn meant that the CDC restricted use of its test to a very small number of laboratories that followed a very specific protocol. They also declined to allow state labs to simply create their own PCR tests.

Beyond this the details are unimportant except to say that the COVID-19 tests used in other countries are also PCR assays, so it’s not as if the CDC was breaking new ground here. And eventually the CDC agreed to limit its test just to COVID-19, which means it no longer has the false positive problem. This took several weeks, and I’m curious why it took so long. But what I’m really curious about is why the CDC didn’t just approve the use of PCR tests that were already being used in China, Europe, and elsewhere. Is there some reason that the United States of America just has to have its very own test instead of using someone else’s test that’s already in the field?

¹Polymerase Chain Reaction. More precisely, it’s an RT-PCR, or Reverse Transcription PCR, which can be used to detect RNA strands. This is what’s needed in the case of COVID-19.

IT'S NOT THAT WE'RE SCREWED WITHOUT TRUMP:

"It's that we're screwed with or without him if we can't show the public that what we do matters for the long term," writes Mother Jones CEO Monika Bauerlein as she kicks off our drive to raise $350,000 in donations from readers by July 17.

This is a big one for us. It's our first time asking for an outpouring of support since screams of FAKE NEWS and so much of what Trump stood for made everything we do so visceral. Like most newsrooms, we face incredibly hard budget realities, and it's unnerving needing to raise big money when traffic is down.

So, as we ask you to consider supporting our team's journalism, we thought we'd slow down and check in about where Mother Jones is and where we're going after the chaotic last several years. This comparatively slow moment is also an urgent one for Mother Jones: You can read more in "Slow News Is Good News," and if you're able to, please support our team's hard-hitting journalism and help us reach our big $350,000 goal with a donation today.

payment methods

IT'S NOT THAT WE'RE SCREWED WITHOUT TRUMP:

"It's that we're screwed with or without him if we can't show the public that what we do matters for the long term," writes Mother Jones CEO Monika Bauerlein as she kicks off our drive to raise $350,000 in donations from readers by July 17.

This is a big one for us. So, as we ask you to consider supporting our team's journalism, we thought we'd slow down and check in about where Mother Jones is and where we're going after the chaotic last several years. This comparatively slow moment is also an urgent one for Mother Jones: You can read more in "Slow News Is Good News," and if you're able to, please support our team's hard-hitting journalism and help us reach our big $350,000 goal with a donation today.

payment methods

We Recommend

Latest

Sign up for our free newsletter

Subscribe to the Mother Jones Daily to have our top stories delivered directly to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate