You can't really define mortality of a disease until you either a) have experience with the disease b) count the dead The mortality is the number of infected divided into the number of dead. You don't know the outcome of those with an ongoing infection; so, the definition is really:
dead/(recovered+dead) We don't really have much experience since there are so many ongoing infections. If you actually use this definition without a lot of experience, the mortality rate is terrifying.
