This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Concept of Health and Disease, Subject name: Social & Preventive Medicine
Which of the following is the best indicator of severity of a short duration acute disease 
Select and explain. 
A. Cause specific death rate, B. 5-year survival, C. Case fatality rate, D. Standardized mortality ratio
C: Case fatality rate
Answer: C: Case fatality rate 
Explanation: 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.