Question

Virulence of a disease is indicated by

• A. . Proportional mortality rate
• B. . Morbidity rate
• C. . Case fatality ratio
• D. . Specific morality rate

Hint:

Remember:
- Morbidity: Sickness/disease occurrence.
- Mortality: Death occurrence.
- Virulence: Severity/deadliness (best measured by CFR - what proportion of sick people die).
- Incidence: New cases.
- Prevalence: Existing cases.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
The question asks for the epidemiological measure that best indicates the virulence of a disease. Virulence refers to the severity of a disease or its ability to cause severe disease or death.

Step 3: Detailed Explanation:
* Case Fatality Ratio (CFR): CFR is the proportion of individuals diagnosed with a disease who die from that disease, within a specified period. It is calculated as:
\[ \text{CFR} = \frac{\text{Number of deaths from a specific disease}}{\text{Number of confirmed cases of that disease}} \times 100 \]
A high CFR indicates that the disease is very severe and likely to cause death among those infected, thus directly reflecting its virulence.
* Proportional mortality rate: This is the proportion of all deaths that are due to a specific disease or cause. It tells about the relative importance of a cause of death but not necessarily its severity among those infected.
* Morbidity rate: This refers to the rate of disease in a population (e.g., incidence or prevalence). It indicates how often a disease occurs or exists but not its severity or deadliness.
* Specific mortality rate: This is a mortality rate calculated for a specific subgroup (e.g., age-specific mortality rate) or for a specific disease. While it indicates deaths, CFR is more directly a measure of severity among cases.
Therefore, the case fatality ratio is the best indicator of a disease's virulence.

Step 4: Final Answer:
Virulence of a disease is indicated by Case fatality ratio.