EID Journal: Estimating Risk for Death from 2019 Novel Coronavirus Disease, China

#15,104

One of the biggest topics of debate, and perhaps the hardest thing to settle right now about COVID-19, is its CFR (Case Fatality Rate). We've seen the most encouraging numbers come from South Korea, which currently hovers below 1%, while at the same time, the CFR in hard hit Lombardy, Italy is over 9%.

The official numbers from Iran come in at about 5%, but there are reports of many deaths not being counted.  Globally - based on `official' numbers - the CFR is sitting about 3.8%, although many mild cases are probably not included in the denominator. 

Where we see the highest CFRs - at least so far - has been in countries and regions that have seen their healthcare system overwhelmed with patients.  Iran, Italy, and the epicenter - Wuhan, China - have all reported very high patient loads and very high CFRs.

While it is possible that some regions are dealing with a slightly more virulent strain of the virus, we've not seen any real evidence to support that.  If all COVID-19 viruses are essentially equally lethal, then the difference likely lies in the ability of local hospitals to provide effective supportive medical care.

All of which brings us to a CDC EID Journal early release, which looks at the risk for death from COVID-19 in China, and finds a 12-fold difference between the CFR in Wuhan City and other, less hard hit areas of China.

Volume 26, Number 6—June 2020
Research
Estimating Risk for Death from 2019 Novel Coronavirus Disease, China, January–February 2020
Kenji Mizumoto and Gerardo Chowell

Author affiliations: Georgia State University, Atlanta, Georgia, USA (K. Mizumoto, G. Chowell); Kyoto University, Kyoto, Japan (K. Mizumoto)

Abstract

Since December 2019, when the first case of 2019 novel coronavirus disease (COVID-19) was identified in the city of Wuhan in the Hubei Province of China, the epidemic has generated tens of thousands of cases throughout China. As of February 28, 2020, the cumulative number of reported deaths in China was 2,858. We estimated the time-delay adjusted risk for death from COVID-19 in Wuhan, as well as for China excluding Wuhan, to assess the severity of the epidemic in the country.

Our estimates of the risk for death in Wuhan reached values as high as 12% in the epicenter of the epidemic and ≈1% in other, more mildly affected areas. The elevated death risk estimates are probably associated with a breakdown of the healthcare system, indicating that enhanced public health interventions, including social distancing and movement restrictions, should be implemented to bring the COVID-19 epidemic under control.

(Continue . . . )

While the CFR of the 1918 Spanish Flu is often cited as ≈ 2% in Europe and the United States, in some areas of the world it was 10% or greater.

It seems we need to put an asterisk beside CFR estimates.  Patient survivability goes way up when prompt and proper medical care is afforded. And it goes way down when such care is significantly degraded or absent altogether. 

The `natural' CFR of COVID-19 - sans medical treatment - may be somewhere between 5% and 10%, at least among those sick enough to need hospitalization. But with good supportive care, that may drop down to 1% or 2%.

Which is why so much emphasis is being placed on `flattening the curve' and keeping hospitals functioning (see Community Pandemic Mitigation's Primary Goal : Flattening The Curve). 

Simply put, the hardships of social distancing will be worth it if we can reduce the number of people who are sick at the same time, thereby reducing the impact on healthcare facilities.

And of course, if we crash the healthcare system with an uncontrolled flood of COVID-19 cases, we also risk depriving everyone with a heart attack, stroke, traumatic injury, or any other medical emergency of help as well.

If we let that happen, things will quickly go from bad to worse.  For everyone.