> By the numbers, 2,470 deaths, 23,419 recoveries, and 53,105 undecided cases. 10% of all settled cases resulted in death.
The mistakenly low estimates of mortality rate are likely due to use of the wrong denominator. As Worldometer [1] explains correctly in their summary of Ghani et al. [2]:
> Once an epidemic has ended, it is calculated with the formula: deaths / cases. But while an epidemic is still ongoing, as it is the case with the current novel coronavirus outbreak, this formula is at the very least “naïve” and can be “misleading if, at the time of analysis, the outcome is unknown for a non negligible proportion of patients.”
[1]: https://www.worldometers.info/coronavirus/coronavirus-death-... "Worldometer Coronovirus Mortality Rate"
[2]: https://doi.org/10.1093/aje/kwi230 "American Journal of Epidemiology Volume 162, Issue 5, Pages 479–486"
As the parent calls out, a better estimate of mortality rate for an ongoing epidemic is deaths / settled cases where settled cases is the sum of deaths and recoveries.
[1] https://www.who.int/docs/default-source/coronaviruse/who-chi...
10% of all settled cases resulted in death. That is far higher than the 3% of Spanish Flu and reasonably close to SARS. Median time to death is around 12 days which is similar to time to recovery meaning the 10% seems likely to be an accurate metric.
https://www.cdc.gov/coronavirus/mers/clinical-features.html
The most interesting part is the ages of cases. Last I checked, there were ZERO deaths of children 9 and under. Mortality rates hover at around 0.2 to 0.3% until over 50.
The really big unknown for me is the weird SARS antibody Antibody-dependent enhancement (ADE) effect. Basically, if the antibody levels get too low and reinfection occurs, the disease becomes much more lethal than if no antibodies are present at all. This effect is now known to be the reason mortality rates for a second case of Dengue fever are so high. In SARS, the disease disappeared before reinfection was an issue. In the case of a pandemic, a second, more lethal wave could be disastrous (if this is also possible with COVID-19). This could also complicate naive vaccines that don't account for possible secondary, enhanced infections.
https://www.sciencedirect.com/science/article/pii/S0006291X1...
All that said, I'm not super-worried.