Question

An epidemic is defined as

• A. Constant presence of disease in a population
• B. Worldwide spread of disease
• C. Sudden increase in disease cases above expected level
• D. Occurrence of rare disease

Hint:

Endemic means constant presence, epidemic means sudden rise above expected level, and pandemic means worldwide spread.

Answer 1

The Correct Option is C

Concept:
Epidemiology deals with the distribution and determinants of diseases in populations. Terms like endemic, epidemic, and pandemic describe disease occurrence patterns.

Step 1: Meaning of epidemic.
An epidemic occurs when the number of disease cases in a population suddenly rises above the expected level.

Step 2: Comparison with endemic.
Endemic means constant presence of a disease in a particular population or geographic area.

Step 3: Comparison with pandemic.
Pandemic means worldwide spread of a disease across countries or continents.

Step 4: Checking other options.
Constant presence of disease is endemic.
Worldwide spread of disease is pandemic.
Occurrence of a rare disease alone does not define an epidemic.
Sudden increase above expected level defines an epidemic.

Step 5: Final answer.
Therefore, an epidemic is a sudden increase in disease cases above the expected level. \[ \boxed{\text{Sudden increase in disease cases above expected level}} \]