In case you think that wearing masks is some liberal plot…

Last week, Kevin Perry called my attention to this news story from South Korea, which has lately been having a “surge” in Covid-19 cases, although in their case that means 19,699 cases and 323 deaths so far in the pandemic. Even if you adjust for the fact that their population is a little less than one sixth of ours, they’re still far ahead of us in terms of their virus response – even though they never closed their border with China (they simply couldn’t). We’re now averaging about 40,000 new cases and 1,000 deaths every day.

The story is that a lady who happened to be infected (and was presumably still asymptomatic) walked into a Starbucks and sat down under the air conditioner. That meant her exhaled droplets spread all over the store, not just in the six-foot space around her. She ended up infecting at least 56 people. This isn’t unprecedented, of course, but the important fact is that most of the other customers weren’t wearing masks all the time, since of course you can’t drink that way.

The only people in the store who consistently wore masks while she was there were the four staff members. And guess what? None of them were infected.

I’m sure this finding could have been reached earlier if there had been scientific studies, where an infected person sits under an air conditioner and half the customers are masked vs. half not masked. But of course that would be unethical. However, the “experiment” has now been done. Anyone who doesn’t pay attention to this is a fool.

Speaking of fools, I wonder if our president has read this story?

The numbers

These numbers are updated every day, based on reported US Covid-19 deaths the day before (taken from the Worldometers.info site, where I’ve been getting my numbers all along). No other variables go into the projected numbers – they are all projections based on yesterday’s 7-day rate of increase in total Covid-19 deaths, which was 4%.

Note that the “accuracy” of the projected numbers diminishes greatly after 3-4 weeks. This is because, up until 3-4 weeks, deaths could in theory be predicted very accurately, if one knew the real number of cases. In other words, the people who are going to die in the next 3-4 weeks of Covid-19 are already sick with the disease, even though they may not know it yet. But this means that the trend in deaths should be some indicator of the level of infection 3-4 weeks previous.

However, once we get beyond 3-4 weeks, deaths become more and more dependent on policies and practices that are put in place – or removed, as is more the case nowadays - after today (as well as other factors like the widespread availability of an effective treatment, if not a real “cure”). Yet I still think there’s value in just trending out the current rate of increase in deaths, since it gives some indication of what will happen in the near term if there are no significant intervening changes.

Week ending	Deaths reported during week/month	Avg. deaths per day during week/month	Deaths as percentage of previous month’s
March 7	18	3
March 14	38	5
March 21	244	35
March 28	1,928	275
Month of March	4,058	131
April 4	6,225	889
April 11	12,126	1,732
April 18	18,434	2,633
April 25	15,251	2,179
Month of April	59,812	1,994	1,474%
May 2	13,183	1,883
May 9	12,592	1,799
May 16	10,073	1,439
May 23	8,570	1,224
May 30	6,874	982
Month of May	42,327	1,365	71%
June 6	6,544	935
June 13	5,427	775
June 20	4,457	637
June 27	6,167	881
Month of June	23,925	798	57%
July 4	4,166	595
July 11	5,087	727
July 18	5,476	782
July 25	6,971	996
Month of July	26,649	860	111%
August 1	8,069	1,153
August 8	7,153	1,022
August 15	7,556	1,079
August 22	7,552	1,079
August 29	6,675	954
Month of August	31,117	1,004	117%
September 5	6,922	989
September 12	7,179	1,026
September 19	7,445	1,064
September 26	7,720	1,103
Month of Sept.	31,136	1,038	100%
Total March – September	219,024

Red = projected numbers

I. Total deaths

Total US deaths as of yesterday: 186,857

Deaths reported yesterday: 872

Yesterday’s 7-day rate of increase in total deaths: 4% (This number is used to project deaths in the table above; it was 4% two days ago. There is a 7-day cycle in the reported deaths numbers, caused by lack of reporting over the weekends from closed state offices. So this is the only reliable indicator of a trend in deaths, not the three-day percent increase I used to focus on, and certainly not the one-day percent increase, which mainly reflects where we are in the 7-day cycle).

II. Total reported cases

Total US reported cases: 6,139,467

Increase in reported cases since previous day: 42,041

Percent increase in reported cases since 7 days previous: 5%  

III. Deaths as a percentage of closed cases so far in the US:

Total Recoveries in US as of yesterday: 3,408,908

Total Deaths as of yesterday: 186,857

Deaths so far as percentage of closed cases (=deaths + recoveries): 5%

For a discussion of what this number means – and why it’s so important – see this post. Short answer: If this percentage declines, that’s good. It’s been steadily declining since a high of 41% at the end of March. But a good number would be 2%, like South Korea’s. An OK number would be 4%, like China’s.

IV. 7-day average of test positive rate for US: 5.9%

For comparison, the recent peak for this rate was 27% in late July, although the peak in late March was 75%. This is published by Johns Hopkins (recent rates for New York state: .8%. For Texas: 15.8%. For Florida: 14.5%.  For Arizona: 8.6%).

I would love to hear any comments or questions you have on this post. Drop me an email at tom@tomalrich.com