NIH Director: Many more Covid infections than official tallies show

And, some other CDC numbers that might surprise you.

Being a numbers guy, a post in the NIH Director’s Blog caught my eye: COVID-19 Infected Many More Americans in 2020 than Official Tallies Show

The specifics:

A recent article published in Nature offers a comprehensive estimate that puts the true number of (covid) infections by the end of 2020 at more than 100 million.

That’s equal to just under 1/3 of the U.S. population of 328 million.

That big number piqued my curiosity: The study was on nearly year old data … what’s the current number?

I was pleased to discover that the CDC regularly posts an Estimated COVID-19 Burden containing data re: cumulative infections, symptomatic illnesses, hospitalizations and deaths.

Here’s my analysis- tweaked extract from the current CDC tabulation of covid infections:


Some takeaways…



> The CDC currently pegs the cumulative incidence of infections over 146 million

> That total translates to almost 45,000 per 100,000 population.

> Since there is some double-counting — i.e. persons who have been infected … and then re-infected … the percentage of covid-infected Americans is less than 45% … probably only slightly less.


Infection Rate

> Surprisingly (to me), the infection rate is highest among those aged 18 to 49


> The infection rate is lowest among those 65 and over — probably reflecting the high (and early) vaccination rate in that group

> And, the estimated infection rate is next lowest among those under 18 …. who haven’t been authorized for vaccinations until recently … hmmm.


Hospitalization Rate

> Across all ages, 5.12% of infections result in hospitalization.

> There’s a very strong correlation between age and likelihood of hospitalization (if infected), e.g. rate is 1% if under 18



Death Rate

> Across all ages, .63% of infections result in hospitalization.

> Death rate is practically zero (.002%) which equates to about 1 in 40,000 for those under 18 who get infected … and not much higher for those 18 to 49

> Middle age death rate is only .58% … about 1 in 170 who get infected

> But, the death rate is almost 4% for those 65 and over … about 1 in 25 who get infected



Technical note:

The covid infection rate estimates are pivotally dependent on estimates of the so-called ascertainment rate —  the percentage of total cases that are confirmed via testing.

The Nature researchers estimate that only about 25% of all infections are confirmed via testing. 

Conversely, 75% are mild or asymptomatic infections that aren’t subjected to (or confirmed by) testing.

Early on, the ascertainment rate was pegged at about 10% … suggesting that total infections were about 10 times the number of confirmed cases.

That multiplier is now pegged at about 4 times confirmed cases since more asymptomatic infections are being detected by forced surveillance testing (e.g. for employment or travel)

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