Thread by @jeremyfaust

“What the eye doesn't see and the mind doesn't know, doesn't exist."
-DH Lawrence, Lady Chatterley's Lover
Remember that as we go through:
A PRIMER explaining why it makes sense that some people think it’s time to re-open the economy...and why they are fatally incorrect.
Thread!

Yesterday, Florida opened its beaches.
Two very important numbers explain why this is probably a very bad idea: (Unless you’re SARS-CoV-2, in which case you’re one psyched little viral particle.)
cnn.com/2020/04/17/us/…

The numbers that we need to understand (and which are a perfect storm for badness) are:
-How many people the average person likely knows who ae infected the virus.
-How many people in a public place it takes to put *many* at risk.

At the moment, those two numbers are a *perfect* recipe/storm for a potential disaster.
In Florida, there are 25,000 cases of SARS-CoV-2, out of 21 million people.
That means that “just” 1 in 840 people have the virus. Feels rare to most people, in life, and on their feeds.

Nationally, the numbers aren’t too different, by the way. There are more cases per capita in New York, somewhat less in other places...but similar orders of magnitude.

This is why it probably FEELS safe for most people to go out & about. The average American knows about 600 people. Even if you have 2000 facebook friends, maybe 2 or 3 of your friends would have a known case. So it seems like these are needles in haystacks. But that’s an illusion

So, it’s the “perfect” moment for a total disaster. Because, as we are about to see, while it FEELS like no one has this disease to the average person (non-hospital workers), but most public settings have enough people that the virus is QUITE likely to be everywhere you go. Why?

Because it’s likely that there are at least 6x (maybe up to 10x) that many infections circulating. And many of these “patients” have no clue. We know that the number of undocumented infections is very high. Up to 86% in one study (Li et at). Two other studies suggest the same

Data from Boston shelters (all residents screened, regardless of symptoms) found that >90% of positive residents were *symptom free. Similarly, data from a NY maternity ward (universal screening) found overwhelming numbers of SARS-CoV2 patients were symptom-free (88% on arrival).

So there may be not 25k but 150k cases in Florida. That means 1 in 140 in Florida has it. Suddenly hanging at the beach let alone other “tighter” public places seems a little scarier. On any given day, you’re not unlikely to be near 140 people. That public restroom? Eh I’d avoid.

This graph, by @joshuasweitz shows just why these numbers are scary. The graph shows the likelihood of being in the same place at the same time with SARS-CoV-2 positive person, given two facts: 1) The number of cases in the US and 2) The number of people at the event you’re at.

Right now, we have around 700,000 cases in the US. (We know the real number is probably 6-10x higher). But just for sake of argument, let’s say a cool million cases. That means that at any gathering with more than 50 people there is WELL over a 25% chance that the virus is there.

In reality there are probably 3-7 mill cases in the US now. Even if it’s just 3 mill cases though, look at that graph. Attending even small events will put you at unreasonably high risk of infection. But the real reason people DON'T GET IT is that the fatality rate remains low.

With 32,000 deaths in the US, out of 327 million Americans, “only” 1 out of 10,218 of us has died of covid-19 (which, btw, is a staggering number, especially considering it was ZERO at the start of March). But it FEELS SMALL (on average 1 in 16 Americans knows someone who died)

Which is why this is such an INCREDIBLY DANGEROUS MOMENT to open. This insanely perilous combination of 1) few enough cases and deaths that it does not “feel real” to most people; 2) but high enough number of cases hiding in plain sight that the risk of public gatherings is great

Q: What CAN and WILL change people's behavior? A: Sadly, when many people know someone who is dead or nearly died of this thing. Since on average we each know “600” people, that would mean 545,000 deaths would be “needed” for it to hit home for all of us. We can’t wait that long.

Even if we assume that we all know more than 600 people...se we all know 2000 people on facebook/social media, it would take 163,500 deaths for Americans all to really see it filling up our social media feeds. That means 5x the number of current deaths would have to occur before.

Btw, if you don’t believe me that the reality we see in our own communities won’t affect behavior, JUST ASK ANY PERSON IN NEW YORK CITY. They have seen what this is all about. And they’re not pushing to open NYC’s great restaurants, music scene, etc yet. They get that safety=life

In closing, we must do tons of testing (viral PCR testing, antibody testing) AND factor in symptom-free cases into our estimates of community prevalence of this virus so that we know city-by-city what the risks are. Once we do this, we can safely re-open when we have low numbers.

The fact that some experts have lowered the predicted deaths to “only” 60,000 is important. It does NOT mean we've been over-reacting. It means what we are doing is a least in some sense working.

The inconvenience of shelter-in-place is worth the lives of our friends, loved ones, neighbors, communities. We can’t get complacent. By the DATA it is too soon.

Lives are on the line. Spread the word. Thanks for reading.

and...

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Be safe, everyone!

fin.