0317 Projection Update

Estimate for today was within 1% again, except Italy was 2% lower on both infections and deaths. That is two days of increasingly lower rates than projected. GOOD JOB ITALY! Their March 22 numbers are on track to be less than the original 1week projection. Death rates are still high, at almost 8%. It’s hard to bring that down, especially since their population is 9 years older than the US, China, South Korea, etc.

The US has been consistently higher than projections. Authorities won’t test for COV19 if you test positive for influenza first. It’s likely the US reporting rate is less than the 14% that China had. On March 22, the US will be higher than the original 1week projection. Death rates are at 1.68%, which is suspiciously low. I am concerned that perhaps deaths are being attributed to other things, or testing is being avoided so that the stats look better. It could also be a new strain of the virus, but I would think that would get a lot of promotion from the government.

I’m having a discrepancy between World vs PRC + nonPRC, with WORLD going high. This may be a random error, but I’m wondering if China’s +30/day is false information. They have kicked out foreign press, and are in a propaganda war with the White House over who’s at fault. The difference is bigger than I would expect could come from the US’s reporting anomalies.

Because of reporting deficiencies, the real number infected is 6-8x the formal numbers, and that typically equates to about a week into the future as a SWAG for real but unreported cases. If you are still going out of the house with non-family members for recreational purposes, you are being selfish, and are a menace to society. If you are doing so to provide essential services, then please be extra careful.

Some of you may have noticed that, if the detection rate is only 14%, then that means the mortality rate is also a sixth of what we think. Yes, but it still spreads too fast, and the absolute numbers of people needing hospital care to survive still would overwhelm hospitals, leading to much higher death rates. So, even if the mortality rate is a flat 0.5% for everyone under age 64, and hospitalization needs are still only 2%, we still need to flatten the curve. At the current rate, and assuming 14% reporting rate, the US is on track to have the whole population infected in one month, with 6 million needing hospital care, and about a million needing external ventillation. We have about a million beds, and about 100k ventillators, with another 60k of old and less effective types. Also, if everyone is sick, who can be the caregivers?

Projections for tomorrow are WW 214086/8769; 81083/3243 PRC; 134076/5591 Non-PRC; 35476/2903 IT; 8901/137 US; 142/1 TX. I think we can expect the US to be 1-2% above projection, and Italy 1-2% below projection. Texas should have additional deaths any day now, but both TX and the US are still tracking substantially lower death rates than expected. I’m hoping to see a slow-down for the US next week. It seems a lot of people got the message for today, and have been reducing their out-of-house socializing.

Projections for 03/17 and 03/22

I run an infection rate projection based on the last 7 days change rates using the JHU case data stats which are updated around 18:30 Central/US each day (vs 04:00 Central/US for the WHO data).

For Monday, 03-16, it was generally within ~1%:

World projection was 179621 confirmed and 7127 dead.
World actual was 181546 confirmed and 7126 dead.

China projection 81029 / 3213.
China actual was 81033 / 3217.

Non-China projection 99472 / did not project dead.
Non-China actual was 100513 / 3909

US Projection 4490 / 74.
US Actual was 4632 / 85.

TX Projection was 91 / 1.
TX Actual was 85 / 1.

For 03/17-18:30ish projections, I have:
Est: WW 196830/7885 ;
PRC 81063/3231;
NonPRC 116869/4721;
IT 31635/2574;
US 6132/115;
TX 100/1 though at low numbers, dead could be 1-6.
For 1 day, I’d expect to be within 2% on any of these numbers.

Note that the real-time trackers are not exactly aligned with this data, and the covid19info.info page I like so much is using a different data source for China, or has not refreshed from the formal stats. They do not match JHU nor WHO, but the other data matches. I’m thinking maybe they run a projection instead of real stats, and need to add newer datapoints.

Also note that Italy and China’s death rates are higher than the US, and higher than the world minus China. If it were just the US, then I would say maybe it’s affluence, or testing anomalies. Instead, I’m thinking that Italy had China’s first strain, and that perhaps the rest of the world has a secondary strain of the virus? I don’t really have the tools, skills, nor time to analyze the gene sequences to build a CV19 family tree to confirm this.

I don’t expect to see a change in the overall growth rates until sometime next week. Pandemic declaration was on the 11th, so Monday the 23rd will probably start to show a dip, plus or minus a day, depending on how much social distancing is actually happening, and when people started. Plenty are still ignoring, or selectively ignoring. I know I ordered food, and the family went to grab things from the university dormitory. Plenty of public facing workplaces still are interacting with unscreened, unlimited people.

For Sunday the 22nd, I’m expecting 262771/11285 worldwide; 81266/3324 China; 259371/14696 non-PRC; 78550/8986 Italy; 25567/280 US; 521/21 Texas. The US numbers could be higher if the two hot zones overrun their hospital capacity, or if a new hot zone pops up. 7 days is a long time, so let’s say it could be plus or minus 25%.

If you want to be safe, then remember that most incubation is under 14 days. People who have self-quarantined for 14 days can co-mingle with other people who have self-quarantined for 14 days and be at very low risk. The longest incubation on record was 27 days, so groups or mutual 27-day self-quarantine would be ultra-low risk. There’s never a zero risk, since there will invariably be one or two asymptomatic carriers. Also, anyone who lies, or anyone who breaks these rules will potentially be a vector for infection into that entire cluster of people. Self-quarantine means no contact outside of a closed group. I’m not sure the increased risk from food deliveries, well-spaced grocery store visits, etc. (Did the cook dip their glove in your food accidentally after scratching their face? Did the stock crew at the store have someone not safe? Did you disinfect the outside of the packages you got in the mail?).


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?

* 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