Numbers, 2: Fwd: "We can now read the Imperial College report" [COVID-19]

[siderea]

Mar 17 2:03 PM: Jeremy C. Young, @jeremycyoung on Twitter writes:

We can now read the Imperial College report on COVID-19 that led to the extreme measures we've seen in the US this week. Read it; it's terrifying. I'll offer a summary in this thread; please correct me if I've gotten it wrong.
https://imperial.ac.uk/media/imperial-college/medicine/sph/ide/gida-fellowships/Imperial-College-COVID19-NPI-modelling-16-03-2020.pdf

The Imperial College team plugged infection and death rates from China/Korea/Italy into epidemic modeling software and ran a simulation: what happens if the US does absolutely nothing -- if we treat COVID-19 like the flu, go about our business, and let the virus take its course?

Here's what would happen: 80% of Americans would get the disease. 0.9% of them would die. Between 4 and 8 percent of all Americans over the age of 70 would die. 2.2 million Americans would die from the virus itself.

It gets worse. People with severe COVID-19 need to be put on ventilators. 50% of those on ventilators still die, but the other 50% live. But in an unmitigated epidemic, the need for ventilators would be 30 times the number available in the US. Nearly 100% of these patients die.

So the actual death toll from the virus would be closer to 4 million Americans -- in a span of 3 months. 8-15% of all Americans over 70 would die.

How many is 4 million people? It's more Americans than have died all at once from anything, ever. It's the population of Los Angeles. It's 4 times the number of Americans who died in the Civil War...on both sides combined. It's two-thirds as many people as died in the Holocaust.

Americans make up 4.4% of the world's population. If we extrapolate these numbers to the rest of the world (warning: MOE is high here), this gives us 90 million deaths globally from COVID-19, in 3-6 months. 15 Holocausts. 1.5 times as many people as died in all of World War II.

Now, of course countries won't stand by and do nothing. So the Imperial College team ran the numbers again, this time assuming a "mitigation" strategy: all symptomatic cases in the US in isolation. Families of those cases quarantined. All Americans over 70 social distancing.

This mitigation strategy is what you've seen a lot of people talking about when they say we should "flatten the curve": try to slow the spread of the disease to the people most likely to die from it, to avoid overwhelming hospitals.

And it does flatten the curve -- but not nearly enough. The death rate from the disease is cut in half, but it still kills 1.1 million Americans all by itself. The peak need for ventilators falls by two-thirds, but it still exceeds the number of ventilators in the US by 8 times.

That leaves the actual death toll in the US at right around 2 million deaths. The population of Houston. Two Civil Wars. One-third of the Holocaust. Globally, 45 million people die: 7.5 Holocausts, 3/4 of World War II. That's what happens if we rely on mitigation & common sense.

Finally, the Imperial College team ran the numbers again, assuming a "suppression" strategy: isolate symptomatic cases, quarantine their family members, social distancing for the whole population, all public gatherings/most workplaces shut down, schools and universities close.

Suppression works! The death rate in the US peaks 3 weeks from now at a few thousand deaths, then goes down. We hit but don't exceed the number of available ventilators. The nightmarish death tolls from the rest of the study disappear.

But here's the catch: if we EVER relax suppression before a vaccine is administered to the entire population, COVID-19 comes right back and kills millions of Americans in a few months, the same as before.

After the 1st suppression period ends in July, we could probably lift restrictions for a month, followed by 2 more months of suppression, in a repeating pattern without triggering an outbreak or overwhelming the ventilator supply. Staggering breaks by city could do a bit better.

But we simply cannot EVER allow the virus to spread throughout the entire population in the way other viruses do, because it is just too deadly. If lots of people we know end up getting COVID-19, it means millions of Americans are dying. It simply can't be allowed to happen.

How quickly will a vaccine be here? Last week three separate research teams announced they had developed vaccines. Yesterday, one of them (with FDA approval) injected its vaccine into a live person, without waiting for animal testing. That's an extreme measure, but necessary.

Now, though, they have to monitor the test subject for 14 months to make sure the vaccine is safe. This part can't be rushed: if you're going to inoculate all humans, you have to make absolutely sure the vaccine itself won't kill them. It probably won't, but you have to be sure.

Assuming the vaccine is safe and effective, it will still take several months to produce enough to inoculate the global population. For this reason, the Imperial College team estimated it will be about 18 months until the vaccine is available.

During those 18 months, things are going to be very difficult and very scary. Our economy and society will be disrupted in profound ways. And if suppression actually works, it will feel like we're doing all this for nothing, because infection and death rates will remain low.

It's easy to get people to come together in common sacrifice in the middle of a war. It's very hard to get them to do so in a pandemic that looks invisible precisely because suppression methods are working. But that's exactly what we're going to have to do. /end

For the record, there is a "critique" of this here which faults this model because:

They ignore standard Contact Tracing [2] allowing isolation of infected prior to symptoms. They also ignore door-to-door monitoring to identify cases with symptoms [3]. Their conclusions that there will be resurgent outbreaks are wrong. After a few weeks of lockdown almost all infectious people are identified and their contacts are isolated prior to symptoms and cannot infect others [4]. The outbreak can be stopped completely with no resurgence as in China, where new cases were down to one yesterday, after excluding imported international travelers that are quarantined.

I haven't been Contact Traced, now have I? We aren't doing door-to-door monitoring. We aren't identifying much of any infectious people and no-one to speak of is being isolated.

They're right about one thing: the outbreak can be stopped complete with no resurgence as in China.

But you have to do what China did.

And we are not doing a 100th of what China did. And continues to do.

And, frankly, the whole point of the thread (and presumably report) they are "critiquing" was precisely that: to get China's results, you must do what China did, which we aren't doing here in the US.

I didn't bother to read the rest of the "critique".

Comments

[athaia]

Nobody in the Western world can do what China did, because we lack the totalitarian system that is handy in those situations, and our populations don't have that collectivist mindset needed to cooperate with those draconic measures. People still think that this is just like the flu. If governments tried a China-style lockdown now, they'd have people rioting - and in the US, the rioters would be armed.

I'm afraid the numbers of deaths need to skyrocket first before the population is willing to try China's response.

[siderea]

Ayup.

[squirrelitude]

I think that if 1) this weren't being so heavily politicized, and 2) the government *asked nicely* for everyone to self-isolate, we could maybe get pretty good compliance. Maybe enough to buy time for us to finally get ramped up on testing, and do contact tracing and whatnot. But that all seems impossible given the current political landscape.

As it is, I think we'll get a big, awful spike in deaths all across the country among those who can't self-isolate (as well as those who won't, because "it's all a conspiracy") and then it will become more manageable. I don't yet have any sense whether we'll *still* need to self-isolate at that point, or whether we'll have largely reached saturation and/or have enough testing abilities. :-/

[sethg]

South Korea isn’t a totalitarian state and it just turned the corner: more recoveries than new cases.

I really wonder how cultural/political differences within the US are going to affect how this plays out. In Boston there’s been a hella lot of self-quarantining since last week, even before it was mandatory; I am reminded of how almost everyone stayed home voluntarily for a couple weeks while hunting down the Marathon bomber. It wouldn’t surprise me if Massachusetts actually manages to bring the infection rate down. But at that point will we just get overrun by plague refugees from Pennsyltucky?

[elf]

Florida has finally closed its Spring Break beaches. On March 15, a cruise ship of 3800 passengers who'd potentially been exposed, disembarked with no questions or restrictions; most of them promptly got on planes to head to their homes. Oklahoma has suggested people avoid restaurants but not mandated closing them. Louisiana has over 700 new cases and 100 tests available per day.

South Korea managed with extensive testing and tracing. We're not doing either. We're not even doing consistent isolation measures. It'll help that big cities are mostly shutting down social venues, especially things like amusement parks, but people "taking advantage of cheap flights" to visit faraway relatives are going to keep the virus spreading fast.

[wobblegong]

Even with all the asterisks and caveats, "I desperately wish the USA would copy China's totalitarian regime" was NOT a thought I expected to ever have. 2020 sure is full of surprises.

[ziggy]

There are reports of welding apartment building doors shut in order to enforce quarantine, and I'm sure there are plenty more asterixes...

[hudebnik]

Somehow, a couple of years ago, I got onto the White House's "1600 Daily" e-mail list, so I get each day's official self-congratulations from the President. The official advice on March 17 (which treats COVID as a more serious threat than any previous White House announcement) reads:

"Avoid crowds of more than 10 people
Wash your hands frequently and thoroughly
Work from home if that’s an option for you
Disinfect frequently touched surfaces
Isolate yourself if you feel sick"

Which is distinctly LESS than the "mitigation strategy" described in the tweet thread (I'm assuming "wash your hands" and "disinfect surfaces" are unspoken prerequisites):

"all symptomatic cases in the US in isolation. Families of those cases quarantined. All Americans over 70 social distancing"

which leads to "only" 2 million Americans dying.

[desireearmfeldt]

Do we have any information about what China has been doing to keep things like food supply, water/electricity/heat, trash removal, etc going? All those things needed to maintain human life and health that require humans to do them?

[kitewithfish]

https://www.businessinsider.com/wuhan-coronavirus-what-life-like-inside-quarantined-city-china-2020-2#but-those-working-to-fight-the-virus-face-the-most-risk-more-than-1700-health-workers-have-been-infected-as-of-friday-china-said-most-are-in-hubei-province-the-home-of-wuhan-32 This article from February seems to show a lot of support and supplies being brought to Wuhan in a very organized way. Obviously this is within a city with a very strict quarantine and large population of ill people, so there's a lot of focus in one place, but it seems like the systems to keep the city running haven't fallen apart, and were receiving extra focused support.

[katuah]

I watched a video series made by a guy in Wuhan who started off working as a driver for medical staff when public transit shut down. Over the weeks, he also rode along with truck drivers and visited a warehouse where they were distributing food. These people were still working.
What I haven't been able to find is 1) what was done in rural areas? were farmers still allowed to send crops to warehouses or processing centers? I'd imagine it looked very different outside the cities - 2) what was the list of "essential" personnel who were allowed/required to keep going to work? In addition to medical staff, I'd think it would have to include sanitation workers, utility workers (water, sewer, power), food & medical supply distribution,.. but did they also keep factories running that make packaged food? Or medical supplies?
f anyone has any good links on that, please share.

[siderea]

Ah, a fellow SpiderMonkeyBread fan!

What I haven't been able to find is 1) what was done in rural areas? were farmers still allowed to send crops to warehouses or processing centers? I'd imagine it looked very different outside the cities

Here's the thing: I think they mostly managed to keep it out of the rural areas. By taking such ruthless steps to contain the outbreaks, they seem to have kept them to a small number of geographical areas, apparently urban.

I'd think it would have to include sanitation workers

I saw a video about the medical sanitation workers - the people picking up and incinerating the hospital waste - and the risks they were at. It was not clear how voluntary their work was.

[sethg]

I recall that after the USSR collapsed, one of the challenges involved in securing its nuclear arsenal was that pre-collapse USSR didn’t do much to secure the actual military bases where nuclear warheads were stored. Nobody much worried about someone breaking into a missile base and driving away with weapons-grade plutonium in their trunk, because, well, with all the internal passports and checkpoints in the country, you couldn’t just go where you wanted no matter what you had in the car.

So I assume that “Red China” has equally effective means to make sure that whoever was in Wuhan, stays in Wuhan.

[sethg]

Both the Imperial College report and the critique are worth reading in full. The authors of the report, themselves, acknowledge that the their model was only looking at the effects of “mitigation policies” such as social distancing, and not taking into account “suppression policies“ such as contact tracing. The people who interpret the Imperial College report as predicting guaranteed apocalypse are not reading it carefully.

If mitigation policies are sufficiently aggressive, it will buy time for public health authorities to marshal their resources, and replace mitigation with suppression after the rate of new infection becomes sufficiently low. That might prevent the fall spike in ICU usage that you see on the Imperial College report graphs.

Or, you know, our government could piss away opportunities to save lives in the summer, just like it pissed away opportunities over the past two and a half months.

[po8crg]

Well, that was weird. I'm an Imperial College alumnus, and the student union there is called "Imperial College Union", or (universally), "ICU".

In the context of Imperial College, it took me about three goes to realise that ICU had to mean "Intensive Care Unit" - there is pretty much always a fall spike in ICU use, as all the new freshers proceed to get thoroughly drunk...