Thread by @DrEricDing

CRITICAL—a negative coronavirus test is **NOT** a ticket to freely socialize without precautions—many are dangerously misguided that it is. It does not negate quarantining, masking & distancing. Here is why 🧵. #COVID19 news.yahoo.com/no-negative-co…

2) There is a virus buildup time — called incubation time—until one usually shows symptoms & viral load high enough to the reliably detected. Usually incubation is 5-6 days, but can be 1-14 days or longer. But if you test too early before viral load builds up, you’ll test neg.

3) This does not mean testing is bad—if anything we need more frequent testing. But you can test negative 4 days straight and then positive on day 5. That’s what happened to WH staff K-McEnany and S-Miller—4 negatives before 5th positive. Most people don’t have that luxury.

4) But we could have frequent texting if more of the new generation rapid antigen tests were available. See thread—this super good test is only available and approved in the EU, but somehow not by FDA yet.

https://twitter.com/drericding/status/1329024406396555269

5) “The point is to use these tests frequently so people are likely to know their status early, before they transmit to others. It is frequency and speed to get results that should take center stage in public health screening program to stop outbreaks”
time.com/5912705/covid-…

6) But back to original article—one test isn’t perfect because it relies on partly timing of the test in catching a sufficient viral load of #SARSCoV2 before tests turn positive. Thus, for purposes of visiting relatives for holidays, it’s risky to rely on a single test alone.

7) some say a negative test means you’re not infectious yet. That maybe true most of the time, but experts say that’s not a reliable indicator of infectiousness since tests can have false neg too. And you’ll likely visit people days after test & doubt many have daily tests.

8) That’s why we still need masks. And ventilation—especially VENTILATION is key. Both ventilation and masks needed to reduce risk indoors. But most buildings not ventilated well enough.

9) And not to sound like broken record, but masks do work (though thicker double cloth, & premium masks like surgical, KN95 & KF94 better). Mask & airborne science compilation video again.

To share yourself—hold down on video & “Tweet video”—and add tag.

10) And here is a sobering graph—even if you are infected (top panel), you still have a pretty decent chance of testing negative. Especially if prior to day 6. Even on day 6-10, you still have ~1 in 4 chance of negative test result even if you have virus! acpjournals.org/doi/10.7326/M2…

https://twitter.com/alinouriphd/status/1330637231946657798

11) these infographics are good. Whether Casey, Kate, or Karen... it can happen all the time. This is what made the virus so damn hard to control in first place.

12) Also please remember our front line healthcare workers. So many have died of #COVID19 already.

https://twitter.com/DrEricDing/status/1330572339118026758