Thread by @AbraarKaran

1//
Let's break down the new US federal policy requiring a negative #covid19 test before boarding announced today because it covers a few important concepts

It requires that people flying into the US have a negative test within 3 days of flying

nytimes.com/live/2021/01/1…

2/ First, this reminds me of the recent outbreak from September on the Dubai-NZ flight.

The index case tested negative 4 days before the flight.

In theory, had they tested within 3 days, infection may have been picked up, but possibly not

https://twitter.com/AbraarKaran/status/1346673607930486785

3/ This highlights the "one test is one test" point: all that test is saying is that you are negative when you got it

That is not a reason to not test-- but it is a reason to want a neg result as close to whatever event it is (flight or otherwise) that you can #covid19

3.5/ Because in those 3 days before the flight, you can definitely incubate virus and infect folks on the flight. The Dubai-NZ situation was 4 days & there were other factors (incomplete masking, vents off for 30 minutes etc); but you get the point

Test to fly interval is key

4/ In the hospital (not all, but where I work), we can get rtPCR tests back by the same day if we can get that swab done in the AM

In Wuhan, back in *FEBRUARY 2020*, their PCR turn around time was 4 hours.

What they managed to do there still to this day astounds me #covid19

5/ Another key point- quarantining

So a negative test before you fly is great- it can potentially reduce transmission in packed flights

But I'm actually more concerned about people landing in new places & going about their business thinking everything is cool

It's not.

6/ Bc that neg test is just that- a snapshot in time- quarantining is key (CDC now says 7 day quarantine w/ a neg test at the end of it is acceptable; I think this is reasonable)

But I fear that many people aren't quarantining the right way (& many frankly can't)

7/ Bc when we say quarantine, we mean quarantine in the house too-- you are basically pretending you are infectious; sleeping separately, staying away from others, masks on in the house, the whole deal

Some people (I suspect) are "quarantining" by staying home, but not more

8/ The irony of all of this-- the US has an even worse epidemic than most other places

Frankly, they should be more worried of us flying there

And we should implement better **domestic flight** policies #covid19

9/ Ultimately, I would not recommend flying at this time either way if you can avoid it bc we should be focusing on reducing mobility/viral spread

Summary
-- reduce that test to flight interval as much as you can

-- quarantine means in the house too!

#Covid19