Calculating Mortality Rates

We have not yet reached 8000 confirmed cases of the Wuhan coronavirus, which means that the current doubling from 4000 cases is taking more than 48 hours to complete. That's up from the 36 hours it took to go from 1000 to 2000 and from 2000 to 4000, but inline with early estimates made when there were less than 1000 reported cases. With 170 deaths, mortality rate remains at about 10%.

However, there are good reasons to believe that the official numbers are incorrect. Not everybody are equally affected by virus infections. Some, like the German case reported a few days ago, will sneeze and cough, run a slight fever, but otherwise be fine. Many of these cases will never be reported. Only severely ill people will show up at a hospital, especially in the midst of an epidemic. People do not go to hospitals without good cause when there's a risk of catching something truly nasty. The official numbers are therefore likely to be based on severe cases only.

Without a measure of how many mild cases there might be, we cannot say anything about the overall mortality rate of the disease. However, we can be pretty sure that the mortality rate among those who get a bad case of this virus is about 10%. This can be calculated by comparing the current number of dead people with the total number of cases that existed or had existed some 2 to 3 days ago. It can also be found from direct measurements of observed groups. Of a group of 40 early cases, 15% died.

From this it is clear that there's no reason for excessive concern. A light cough, some sneezing, and a mild fever is all that most people who catch this will experience, and even if it gets worse, the survival rate is at 90%.

By DoD - http://www.defenselink.mil/pubs/pdfs/App12_Pt12.pdf, Public Domain, Link