A pay was attended by a group of 100 people. Out of 100, 60 cases were repoed to be infected with food poisoning. 12 deaths were recorded. what is the case fatality rate in above scenario?
First, I need to recall what case fatality rate means. CFR is the proportion of deaths among diagnosed cases of a disease. The formula is (Number of deaths / Number of confirmed cases) × 100. So here, the number of deaths is 12, and the number of confirmed cases is 60. So CFR would be (12/60)*100 = 20%.
Now, the core concept here is understanding CFR versus other rates like attack rate or mortality rate. Attack rate would be cases divided by total population at risk, which is 60/100 = 60%. Mortality rate is deaths divided by total population, which is 12/100 = 12%. But the question specifically asks for CFR, so the correct answer is 20%.
Looking at the options, the correct answer is 20%, which would be option C if the options were A to D with C being 20%. The other options would be distractors. For example, option A might be 12% (deaths over total population), B could be 60% (attack rate), D might be 12/100 = 12% again. Each of these is a common mistake, so explaining why they're wrong is important.
Clinical pearl: Remember that CFR is deaths divided by confirmed cases, not total population. This is a classic exam trap where they mix up rates. So the key is to identify the correct denominator based on the question's wording.
I need to structure the explanation with the required sections: Core Concept, Why Correct Answer is Right, Why Each Wrong Option is Incorrect, Clinical Pearl, and Correct Answer Line. Make sure to use bold for section headers and key terms. Keep each section concise, within the character limit. Avoid markdown except for bold and bullet points where needed. Use precise medical terms like "case fatality rate," "attack rate," "mortality rate," etc. Also, check that the explanation is clear for postgraduate students, using examples of common mistakes and mnemonics if possible.
**Core Concept**
Case fatality rate (CFR) is a measure of disease severity, calculated as **(Number of deaths from the disease / Total number of confirmed cases) × 100**. It reflects the proportion of individuals diagnosed with a condition who die from it, distinct from mortality rate (deaths per population) or attack rate (cases per population).
**Why the Correct Answer is Right**
In this scenario, 60 individuals were infected (confirmed cases), and 12 died. Applying the CFR formula: **(12 deaths ÷ 60 cases) × 100 = 20%**. This metric specifically evaluates the lethality of the disease among those who contracted it, not the broader population.
**Why Each Wrong Option is Incorrect**
**Option A:** Likely 12% (12 deaths ÷