Update -- COVID-19 Model: Estimated Number of Infected Individuals Based on the Number of Deaths

I've had a chance to examine my model in light of evidence from South Korea that I collected from the Johns Hopkins CoronaVirus Resource Center (https://coronavirus.jhu.edu/map.html.) South Korea has clearly had one of the best if not the best COVID-19 mitigation strategy that has a centerpiece aggressive testing. Therefore, South Korea's numbers should be the most up to date and accurate.

As of 16 March 2020, South Korea's numbers are:

• 8,162 infected
• 75 deaths

Johns Hopkins doesn't breakdown the deaths by age group, however, I entered what I believe are realistic numbers into the fields. Here are the results:

Age Ranges, Years	Rate of Death	Reported Deaths	Projected Number of Infected at Present (based on average time of illness until death)	Projected number of who are infected now	Projected number of deaths based on the number currently infected (based on average time of illness until death)
80 plus	0.148	21	142	803	119
70-79	0.08	17	213	1202	96
60-69	0.036	13	361	2043	74
50-59	0.013	8	615	3481	45
40-49	0.004	7	1750	9899	40
30-39	0.002	4	2000	11314	23
20-29	0.002	4	2000	11314	23
10-19	0.002	1	500	2828	6
0-9	0.0	0	948	5360	0
Infection rate	2.0
Average time of illness until death (weeks)	2.5
Total Infected based on current number of deaths	8528
Total Infected Now	48244
Total number of deaths	75
Projected total number of deaths based on the current number of infected individuals	424

The numbers to focus on are "Total Infected based on current number of deaths" and the "Total number of deaths." I'm assuming that the total number of infected in South Korea is close to being complete. I'm estimating that South Korea has 8528 infected individuals. However, because of the lack of testing in the US, I would estimate that when the US reaches 75 deaths, that in reality there are 48244 infected. And that the US will see 424 deaths within 2.5 weeks.

I noted one flaw in my estimator. Every cell of reported deaths from 80 plus to 10-19 must have a number other than zero to achieve a reasonable number of infected estimate for that age group. I'll see if I can build in correction mechanism that would enable one to enter zero for an age group and still have a reasonable estimate of the number who are infected. 

Update: Estimate of the Number of Infected in the US Based on Current Number of Deaths (16 March 2020)

As of today, the number of COVID-19 deaths is 74. Based on that information, here's what I estimate to be the number of infected.

Age Ranges, Years	Rate of Death	Reported Deaths	Projected Number of Infected at Present (based on average time of illness until death)	Projected number of who are infected now	Projected number of deaths based on the number currently infected (based on average time of illness until death)
80 plus	0.148	21	142	803	119
70-79	0.08	17	213	1202	96
60-69	0.036	13	361	2043	74
50-59	0.013	8	615	3481	45
40-49	0.004	7	1750	9899	40
30-39	0.002	4	2000	11314	23
20-29	0.002	3	1500	8485	17
10-19	0.002	1	500	2828	6
0-9	0.0	0	885	5007	0
Infection rate	2.0
Average time of illness until death (weeks)	2.5
Total Infected based on current number of deaths	7966
Total Infected Now	45062
Total number of deaths	74
Projected total number of deaths based on the current number of infected individuals	419

I decided to use fundamentally the same distribution pattern as I estimated for South Korea. These are the results:

• The estimate for the number infected throughout the US this day is 45,062. 
• 7966 people were infected 2.5 weeks ago.
• Approximately 2.5 weeks from today (end of March, first of April) I estimate 419 people will have died from COVID-19. I suspect that's a low estimate. If 17% of those infected require hospitalization at one point or another, I suspect that many will not receive treatment because of lack of resources and personnel. And many more will die due only to the lack of treatment because of the lack of preparation. 

A Second Update Regarding the US (16 March 2020)

I just heard that the number of deaths is 80. So based on that new number, these are my estimates:

Age Ranges, Years	Rate of Death	Reported Deaths	Projected Number of Infected at Present (based on average time of illness until death)	Projected number of who are infected now	Projected number of deaths based on the number currently infected (based on average time of illness until death)
80 plus	0.148	24	162	917	136
70-79	0.08	18	225	1273	102
60-69	0.036	13	361	2043	74
50-59	0.013	10	769	4351	57
40-49	0.004	7	1750	9899	40
30-39	0.002	4	2000	11314	23
20-29	0.002	3	1500	8485	17
10-19	0.002	1	500	2828	6
0-9	0.0	0	908	5139	0
Infection rate	2.0
Average time of illness until death (weeks)	2.5
Total Infected based on current number of deaths	8176
Total Infected Now	46250
Total number of deaths	80
Projected total number of deaths based on the current number of infected individuals	453

• The estimate for the number infected throughout the US this day is 46,250.
• 8176 people were infected 2.5 weeks ago.
• Approximately 2.5 weeks from today (end of March, first of April) I estimate 453 people will have died from COVID-19.