<prompt> Which of the following is the best indicator of severity of a short duration acute diseaseCause specific death rate5-year survivalCase fatality rateStandardized mortality ratio  <response>: 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. 