SARS-COV-2

SARS-COV-2, COVID-19, nCOV-2019, Wuhan Virus, SARS2, and a slew of other names mostly refer to the same thing, either the virus, or the disease.

Someone recently asked if we have an accurate representation of the rate of infection in the US vs the population count. We do have an accurate representation of the rate of infection in the US. The US is averaging 1.35x total confirmed cases per day over the last 12 days. Based on Friday’s numbers, we were at 7.83x vs the prior week (fluctuating), and 62x vs the prior 20 days (also fluctuating). I chose 20 days because that’s the median time from exposure to recovery, but that duration can vary.

Mortality rate is 2.2% of confirmed cases. However, there are tons of non-confirmed, unknown cases. Those show up as a reporting lag of 8-12 days. What that means is, if we isolated every single person right now without any further cross-contamination, and had a perfect detection rate, we would have an end-state between 21k and 73k cases in the US.

The ratio to infected population is not as useful of a statistic when the average person struggles to internalize what exponential growth really means. We say “oh, it looks like such a small number”, but the biggest growth is in the last days. For example, based on our rate of infection for the last 12 days, we will hit 100% infection rate on April 20. Realistically, it slows well before that, but just as an example. So, on April 19, we are at 70%, and a week earlier, we are at 11%.

A more useful number might be the days to 100% (38 days), but even that seems a bit far away. Plenty of time left to dilly dally.

How about the days to hospital overload? What exactly is hospital overload?

That is the time when caregivers have to choose someone to die.

This one is more difficult, because there will be clusters where it’s really bad, and areas where it’s not as bad. However, the US has 2.8 hospital beds per 1000 people. 65% of those are in use. Not all of them are convenient, but some areas will convert ORs and hallways to extra room, so we’ll assume we can use 100% of these. For reference, Italy has 3.2, Hubei has 4.3, and South Korea, has 12.

So, we have an estimated 328k hospital beds available. 16% of the confirmed cases need a hospital bed, which means complete hospital overrun occurs at 6.5 million active infected. Realistically, it will be overrun at less, because there will be regions devastated while other areas don’t see a big problem (TX is a week behind the US, for instance.)

But the other thing is that 5% of the total confirmed will need ICU care with ventillation. We have about 100k of those, though not all accept all types of patients, and again, many of them are in use already. We’ll still count them all as universal. At 700k active infections, we run out of the needed ICU beds. (35% available, 5% need them). After that, the overall death rate climbs rapidly.

So, days to 700k active infections is about 18. We lose 8-12 days due to lag in detection. That means we have 6 to 10 days to stop ignoring the experts before we are committed to it being horrible. Plus or minus 2 days based on where clusters are, vs where beds are, etc.

So, we might have just 4 days left to be jackasses abut this, and that is why everyone is overreacting, declaring states of emergency, and freaking out over toilet paper. Maybe we have 12 days, or maybe people are really good about social distancing in the digital age, but that has not shown up in the numbers yet. I hope it does soon.

And then you say, “But, it seems FINE right now!” and in 4 days, you also say “SEE, IDIOT! It’s absolutely FINE!”

And then your parents die because you were selfishly insisting that it’s “just a bad flu”. I don’t want to be right. I don’t want you to suffer. I want you to be safe, even if you’re pissed off and don’t understand.

“But I have a right to live my life!” Only insofar as you do not put others at risk that they are not willing or able to accept. Your right to do whatever you want is not infinite nor absolute.

“But we’ll all get sick anyway!” YES! We will; however, if 90% of us can do so from a vaccine in summer of 2021, that would be way cooler than having to have a million or so people die earlier than that.

“Let the strong survive!” Are you certain that’s you? Tougher people than you died in the Spanish Flu pandemic of 1918.

“The FLU kills more people!” You’re ignoring the exponential factor. The flu came over and got tons of people all at once. We’re hundreds of days further into it to get these flu death numbers, and that’s because the mortality rate of the flu is a tiny fraction of SARS2. Flu deaths are about 0.1% of the confirmed cases, and those are about 23% of the tested patients. Plenty of patients never get tested, so just like SARS2, the real number is much lower.

Compare 0.1 to 2.4 though. Not even in the same balpark. You think it’s not hazardous, because not many people are confirmed infected, but the number infected is 7.8x now compared to what it was a week ago. 28k confirmed in a week. 252k confirmed in 2 weeks, and now we’ve caught up with reporting lag. That’s 6k dead. In 3 weeks, that’s 2.3 million confirmed, and 2.0 million active cases. We’ve overrun ICU, so we go to 3.6% mortality rate, and that’s 81k dead. Three weeks of ignoring quarantine is all it takes to reach quadruple the entire flu deaths to date for this flu season.

Or, we deal with this really frustrating situation as if we have a little bit of self control, self respect, and overall integrity. We keep from overrunning hospital capacity, and hospitals increase capacity. We clamp this down now, so we can mostly go about our business later (though there will be spot quarantines until vaccination or herd immunity becomes available.)

Anything I missed in here?

REFERENCES:
* Live tracker with decent data visualization – https://covid19info.live/
* Johns Hopkins Data Visualization (Mobile) – https://www.arcgis.com/apps/opsdashboard/index.html#/85320e2ea5424dfaaa75ae62e5c06e61
* Johns Hopkins University Raw Data – https://github.com/CSSEGISandData/COVID-19
* World Health Organization Situation Reports – https://www.who.int/emergencies/diseases/novel-coronavirus-2019/situation-reports


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