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Tue Mar 10, 2020, 12:54 AM

The Math: Dire Warnings Reposted w/New Info [View all]

It is time to stay home if you can! Read new links & this report

MATH - The following analytics highlights the exponential coronavirus disaster about to explode BEFORE MAY and overwhelm USAís woefully unprepared medical capacity to treat coronavirus patient load UNLESS we each commit to social distancing for a few weeks to SLOW DOWN the spread.

The Task Teams in your area need this information ASAP so pass it along.

In a nutshell, we can do our part via social distancing to slow down the spread of this virus to avoid overwhelming US medical capacity. This graph proves this point

Or see graph proving how we can each help avoid overwhelming medical capacity here for non-twitter users


Without social distancing The Math proves the risks of overwhelming medical capacity

BUT WAIT! New Report out of China

Coronavirus can travel twice as far as official Ďsafe distanceí and stay in air for 30 minutes, Chinese study finds


AND this report of the medical disasters unfolding as reported by an Italian Doctor


The following is a Twitter report by Liz Specht, a PhD scientist

The Math

I think most people arenít aware of the risk of systemic healthcare failure due to #COVID19 because they simply havenít run the numbers yet. Letís talk math. 1/n

Letís conservatively assume that there are 2,000 current cases in the US today, March 6th. This is about 8x the number of confirmed (lab-diagnosed) cases. We know there is substantial under-Dx due to lack of test kits; Iíll address implications later of under-/over-estimate. 2/n

We can expect that weíll continue to see a doubling of cases every 6 days (this is a typical doubling time across several epidemiological studies). Here I mean *actual* cases. Confirmed cases may appear to rise faster in the short term due to new test kit rollouts. 3/n

Weíre looking at about 1M US cases by the end of April, 2M by ~May 5, 4M by ~May 11, and so on. Exponentials are hard to grasp, but this is how they go. 4/n

As the healthcare system begins to saturate under this case load, it will become increasingly hard to detect, track, and contain new transmission chains. In absence of extreme interventions, this likely wonít slow significantly until hitting >>1% of susceptible population. 5/n

What does a case load of this size mean for healthcare system? Weíll examine just two factors ó hospital beds and masks ó among many, many other things that will be impacted. 6/n

The US has about 2.8 hospital beds per 1000 people. With a population of 330M, this is ~1M beds. At any given time, 65% of those beds are already occupied. That leaves about 330k beds available nationwide (perhaps a bit fewer this time of year with regular flu season, etc). 7/n

Letís trust Italyís numbers and assume that about 10% of cases are serious enough to require hospitalization. (Keep in mind that for many patients, hospitalization lasts for *weeks* ó in other words, turnover will be *very* slow as beds fill with COVID19 patients). 8/n

By this estimate, by about May 8th, all open hospital beds in the US will be filled. (This says nothing, of course, about whether these beds are suitable for isolation of patients with a highly infectious virus.) 9/n

If weíre wrong by a factor of two regarding the fraction of severe cases, that only changes the timeline of bed saturation by 6 days in either direction. If 20% of cases require hospitalization, we run out of beds by ~May 2nd. 10/n

If only 5% of cases require it, we can make it until ~May 14th. 2.5% gets us to May 20th. This, of course, assumes that there is no uptick in demand for beds from *other* (non-COVID19) causes, which seems like a dubious assumption. 11/n

As healthcare system becomes increasingly burdened, Rx shortages, etc, people w/ chronic conditions that are normally well-managed may find themselves slipping into severe states of medical distress requiring intensive care & hospitalization. But letís ignore that for now. 12/n

Alright, so thatís beds. Now masks. Feds say we have a national stockpile of 12M N95 masks and 30M surgical masks (which are not ideal, but better than nothing). 13/n

There are about 18M healthcare workers in the US. Letís assume only 6M HCW are working on any given day. (This is likely an underestimate as most people work most days of the week, but again, Iím playing conservative at every turn.) 14/n

As COVID19 cases saturate virtually every state and county, which seems likely to happen any day now, it will soon be irresponsible for all HCWs to not wear a mask. These HCWs would burn through N95 stockpile in 2 days if each HCW only got ONE mask per day. 15/n

One per day would be neither sanitary nor pragmatic, though this is indeed what we saw in Wuhan, with HCWs collapsing on their shift from dehydration because they were trying to avoid changing their PPE suits as they cannot be reused. 16/n

How quickly could we ramp up production of new masks? Not very fast at all. The vast majority are manufactured overseas, almost all in China. Even when manufactured here in US, the raw materials are predominantly from overseas... again, predominantly from China. 17/n

Keep in mind that all countries globally will be going through the exact same crises and shortages simultaneously. We canít force trade in our favor. 18/n

Now consider how these 2 factors Ė bed and mask shortages Ė compound each otherís severity. Full hospitals + few masks + HCWs running around between beds without proper PPE = very bad mix. 19/n

HCWs are already getting infected even w/ access to full PPE. In the face of PPE limitations this severe, itís only a matter of time. HCWs will start dropping from the workforce for weeks at a time, leading to a shortage of HCWs that then further compounds both issues above. 20/n

We could go on and on about thousands of factors Ė # of ventilators, or even simple things like saline drip bags. You see where this is going. 21/n

Importantly, I cannot stress this enough: even if Iím wrong Ė even VERY wrong Ė about core assumptions like % of severe cases or current case #, it only changes the timeline by days or weeks. This is how exponential growth in an immunologically naÔve population works. 22/n

Undeserved panic does no one any good. But neither does ill-informed complacency. Itís wrong to assuage the public by saying ďonly 2% will die.Ē People arenít adequately grasping the national and global systemic burden wrought by this swift-moving of a disease. 23/n

Iím an engineer. This is what my mind does all day: I run back-of-the-envelope calculations to try to estimate order-of-magnitude impacts. Iíve been on high alarm about this disease since ~Jan 19 after reading clinical indicators in the first papers emerging from Wuhan. 24/n

Nothing in the last 6 weeks has dampened my alarm in the slightest. To the contrary, weíre seeing abject refusal of many countries to adequately respond or prepare. Of course some of these estimates will be wrong, even substantially wrong. 25/n

But I have no reason to think theyíll be orders-of-magnitude wrong. Even if your personal risk of death is very, very low, donít mock decisions like canceling events or closing workplaces as undue ďpanicĒ. 26/n

These measures are the bare minimum we should be doing to try to shift the peak Ė to slow the rise in cases so that healthcare systems are less overwhelmed. Each day that we can delay an extra case is a big win for the HC system. 27/n

And yes, you really should prepare to buckle down for a bit. All services and supply chains will be impacted. Why risk the stress of being ill-prepared? 28/n

Worst case, Iím massively wrong and you now have a huge bag of rice and black beans to burn through over the next few months and enough Robitussin to trip out. 29/n

One more thought: youíve probably seen multiple respected epidemiologists have estimated that 20-70% of world will be infected within the next year. If you use 6-day doubling rate I mentioned above, we land at ~2-6 billion infected by sometime in July of this year. 30/n

Obviously I think the doubling time will start to slow once a sizeable fraction of the population has been infected, simply because of herd immunity and a smaller susceptible population. 31/n

But take the scenarios above (full beds, no PPE, etc, at just 1% of the US population infected) and stretch them out over just a couple extra months. 32/n

That timeline roughly fits with consensus end-game numbers from these highly esteemed epidemiologists. Again, weíre talking about discrepancies of mere days or weeks one direction or another, but not disagreements in the overall magnitude of the challenge. 33/n

This is not some hypothetical, fear-mongering, worst-case scenario. This is reality, as far as anyone can tell with the current available data. 34/n

Thatís all for now. Standard disclaimers apply: Iím a PhD biologist but *not* an epidemiologist. Thoughts my own. Yadda yadda. Stay safe out there. /end

Addendum: to anyone who found this useful or interesting, highly recommend you follow @trvrb who actually does modeling and forecasting for a living. This thread is a great place to start: twitter.com/trvrb/status/1Ö

Lastly, SLOWING the spread has to be our collective goal! Please do your part.

Collectively, we can SAVE LIVES!

Hereís directives from Kings County, Washington State

Coronavirus Disease 2019 (COVID-19) Public Health recommendations to protect our community


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Reply The Math: Dire Warnings Reposted w/New Info [View all]
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captain queeg Mar 2020 #2
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mmbrevo Mar 2020 #17
brewens Mar 2020 #5
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OhNo-Really Mar 2020 #14
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captain queeg Mar 2020 #18
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