Thread by @Craig_A_Spencer

🖍️ & 🥃 Episode 1 : TRANSMISSION

We've all heard about #coronavirus, right?!

So many of you have questions around how it's transmitted.

Does it survive on surfaces? Is it in my poop?

Or the air? And what about on my packages?

So let's talk about transmission!

THREAD 👇

So what are the most common routes of transmission?

MOST COMMON is via respiratory droplets.

These are usually transmitted by coughing or sneezing.

Most of these droplets can travel up to ~3 feet (1 meter).

And they can infect when they land on your mucosa (👃/👄) or 👀.

THIS is why wearing a mask - which decreases YOU spreading the virus if you’re sick & may help prevent the virus from infecting you - is so crucial!

It’s also why distancing - at least 6 feet - is important.


Remember, the virus cannot infect you if the virus cannot find you!

But not all transmission is via droplets - there’s also ‘contact’. This means encountering virus on surfaces (not droplets themselves).

So if you touch a surface with virus on it (from someone's cough, contaminated hands) & then touch your mouth/nose/eyes, infection IS possible.

A study in @TheLancet found the virus survives for at least 30 mins on paper, 1 day on wood and cloth, 2 days on glass, and 4 days on plastic & steel.

And the virus can last on surgical masks for 7 days!

But these were lab experiments & might not reflect real-life conditions!

(p.s. do you have questions about masks and how to use them? If so, check out this thread by yours truly from a few weeks ago):

https://twitter.com/Craig_A_Spencer/status/1246857275488309250?s=20

Another study in @NEJM found that NO viable virus was detected after 72 hrs for ➡️ surfaces (plastic, stainless steel, copper and cardboard). AND the amount of virus was greatly reduced quickly and as time passed.

On copper, no viable SARS-CoV-2 was measured after 4 hours. On cardboard, no viable SARS-CoV-2 was measured after 24 hours.

The takeaway is that virus CAN survive on surfaces for relatively short periods.

Just a reminder of the importance of washing your hands 🙏🙌!

So...what about AIRBORNE?!?

Let's start with the facts. The science is inconclusive, but NO documented cases have been documented from airborne transmission.

Airborne transmission is NOT a major mode of transmission.

But there are a few principles and studies worth mentioning.

In hospitals, we're concerned that some procedures - like placing a breathing tube - could aerosolize (make airborne) the virus. That's why we wear specific protective equipment.

A new article in @nature found aerosol particles in a hospital, esp. in areas with poor ventilation.

There are other studies in restaurants & call centers that have suggested possible aerosol transmission - but those were small, poorly-ventilated spaces, and so any infections may actually be from respiratory droplets.

Plus they measured RNA - not the infectious virus itself! 👇

What about poop (fecal-oral transmission):

The @cdc says it's 'unclear whether the virus found in feces may be capable of causing COVID-19. There has not been any confirmed report of the virus spreading from feces to a person.'

So...💩 is not a significant source of infection.

And what about your mail and packages? Can they spread SARS-CoV-2?

To date, there are NO documented cases of transmission via mail or packages.

But it's always a good idea to wash your hands after opening mail/packages, or just let them sit for 24 hours.

What about getting the virus from take-out food?

It's unlikely. Cooking kills the virus. If you don't literally inhale your food and you'll be ok!

If you're weary or immunocompromised, you could stick with cooked food and stay away from salads to be safe.

And wash your hands!

What about shoes? A study found virus on shoes in 2 Wuhan hospitals - but again, unlikely to infect you. Wash your hands or sanitize after handling.

And do you need to wash your clothes after a run to the grocery store?

Only if someone coughed on you! Otherwise, you're good.

So, the takeaways:

The OVERWHELMINGLY main mode of transmission is respiratory droplets. That's why wearing a mask and social distancing are SO important!

Next is transmission via contact with infected surfaces. Less common, but still important. So wash your hands!!!

Other routes - fecal-oral, clothing, airborne - are possibilities but haven't been tied to any known infections.

There's more we don't know about COVID than we do, so this may change!

But right now, the best thing you can do is:

1. #StayHome!
2. Wear a mask
3. Wash your hands

I wanted to thank everyone who asked a question about transmission, and hope your questions were answered here!

@kadiebug12 @djdth31 @50shekels @pjd93920 @kimmyhippielove @constantguide @pdmj007 @debrajepson @travelwithtrent @xanthematy @marlipie

For our next episode, we’ll tackle your questions about testing - so check this space tomorrow at 9pm!

This thread (and future ones) + all supporting articles & research can be found at: bit.ly/3bRycHQ

Thanks to @TylerWen & @saurabhsudesh for helping put this together!

And as a reminder, the goal is to share something like every night to address big questions around testing, treatments, vaccines, pathophysiology and more!

Every night at 9pm unless I run out of crayons...or whiskey.

Be safe! ❤️