Thread by @skarlamangla

Just when you thought it couldn't get any worse in LA: The FDA is warning that the COVID tests used at our testing sites have a high false negative rate. In other words, they often say you don't have COVID when you do. fda.gov/medical-device…

Curative, the company that makes the tests, processes 35,000 samples a day from LA, according to its CEO.

Overall, LA County is testing around 85,000 people a day, so Curative testing makes up a huge portion of that. They run testing at the massive site at Dodger Stadium.

The FDA warns that Curative tests should be "limited to symptomatic individuals."

This is so different from what LA officials have been promoting: testing for everyone, symptoms or not.

In fact, testing of asymptomatic people has been a major point of pride for LA.

The FDA notice doesn't differentiate between the oral and nasal swabs. I'm not sure if LA Curative sites use nasal swabs -- I've only ever seen oral. But there have been concerns in the past about oral swabs not being sensitive enough.

Our reporters did a story in April about the risk LA was taking by adopting a testing method that was not 100% certain and could yield false negatives, featuring this reassuring quote: " “This kind of test is better than nothing."

latimes.com/california/sto…

In June, LA health services director Dr. Christina Ghaly said that too many false negatives had convinced them to switch from oral to nasal swab. But that hasn't happened uniformly across LA County.

Ghaly: "While oral approach was effective, studies -- multiple studies -- have shown that a switch to the nasal swab is better and leads to a better specimen collection, better sensitivity and will lead to fewer false negative test results."

I don't actually know what Curative's false negative rate is. In this story it says 10%, but the FDA didn't specify. dot.la/curative-kiosk…

So far, this is what Curative CEO has said about the debacle.

"The firm 'disagrees with the assessment' made by FDA that the test has performance issues, he said. The firm intends to publish the results of a large clinical trial soon." modernhealthcare.com/supply-chain/f…

tldr; don't roam free, ignore pandemic precautions, go to your high-risk job and then get a test and decide you're not infected with the coronavirus. even better tests than this one have false negatives. a test is not a passport to do whatever you want.

here's a cautionary tale about false negatives with any kind of testing: latimes.com/california/sto…

how Curative became LA's provider of COVID tests: labusinessjournal.com/news/2021/jan/…

“Mayor Garcetti is incredibly grateful for their partnership," said the mayor's spokesman.