Virulence of a disease is indicated by:: (A) Proportional mortality rate, (B) Specific mortality rate, (C) Case fatality rate, (D) Amount of GDP spent on control of disease
Answer is C. Ans. (c) Case fatality rateCASE FATALITY RATE (CFR):* CFR represents 'killing power of a disease'- It is 'closely related to virulence of organism'CFR=Totalno.ofcasesduetoadiseaseTotalno.ofdeathsduetoadisease x100* CFR is a Proportion: Always expressed in percentage* CFR is the 'complement of Survival Rate', thus CFR =1 - Survival Rate* Limitations of CFR:- Time interval is not specified- Usefulness is limited for chronic diseases - CFR for the same disease may vary in different epidemics