In a village of 5000 population, 50 persons suffered from cholera and 10 persons died. What will be the case fatality ratio?
**Core Concept**
The case fatality ratio (CFR) is a measure of the severity of a disease, calculated as the proportion of individuals with the disease who die from the disease. It is an important epidemiological parameter used to quantify the mortality associated with a particular disease.
**Why the Correct Answer is Right**
To calculate the CFR, we need to divide the number of deaths due to the disease by the number of individuals who developed the disease. In this case, 10 persons died out of 50 who suffered from cholera. Therefore, the CFR is calculated as 10/50, which simplifies to 1/5 or 0.2. This means that 20% of individuals who developed cholera died from the disease.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not consider the number of individuals who developed the disease. Without this denominator, the CFR cannot be accurately calculated.
**Option B:** This option is incorrect because it multiplies the number of deaths by the total population, which is not the correct method for calculating CFR.
**Option C:** This option is incorrect because it adds the number of deaths to the number of individuals who developed the disease, which is a mathematical error.
**Clinical Pearl / High-Yield Fact**
Remember that CFR is a useful epidemiological parameter for assessing the severity of a disease, but it can be influenced by various factors such as access to healthcare, quality of care, and the effectiveness of treatment.
**Correct Answer: A. 0.2. 20%**