Which of the following is the best indicator of severity of a short duration acute disease

i.e. Case fatality rate * Case fatality rate is actually a ratioCase fatality rate =Total no.of deaths dueto a particular diseaseTotal no.of cases dueto the same diseasex 100* Case fatality rate represents the killing power of the disease* It is useful in acute infectious disease e.g. food poisoning, cholera, measles.* Its use for chronic disease is limited* Case fatality rate for the same disease may vary in different epidemics* It is related to virulence of the disease.