Clustered ases of diarrhea occurring around a contaminated well represent which type of epidemic?

AIIMS M.Sc. Nsg Entrance exam-2026

Community Health Nursing

Medium

Appeared in: AIIMS M.Sc. Nsg Entrance exam-2026

Explanation

A point source epidemic involves exposure to a disease agent that is brief and essentially simultaneous for the affected group.
The key features are an explosive onset and a clustering of cases within a narrow interval of time, all developing within one incubation period.
In this scenario, the 'contaminated well' is the single common source, and 'clustered cases' points to a single, short-term exposure event, fitting the definition perfectly.

Option A: A propagated epidemic results from person-to-person transmission. The scenario describes a common source (the well), not spread between individuals.
Option B: A continuous common source epidemic involves prolonged or repeated exposure to a source over time, leading to an extended, irregular epidemic curve. The term 'clustered' suggests a short, single exposure.
Option D: This phrase describes the general definition of an epidemic ('occurrence of cases... in excess of normal expectancy'), not a specific type based on the pattern of spread.

Visual 1: Infographic: Comparison of Epidemic Curves. A line graph showing the three classic epidemic curves: 1) the sharp, single peak of a point source epidemic; 2) the elevated plateau of a continuous common source epidemic; and 3) the series of progressively larger peaks of a propagated epidemic. This visual helps differentiate the patterns of disease outbreak over time.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Types of Epidemics (Common Source vs. Propagated) as background academic context rather than a clinical decision trigger.
Identifying the type of epidemic is a critical first step for public health nurses in controlling an outbreak.
For a point-source epidemic like this, the immediate priority is to identify and eliminate the common source (e.g., decontaminating or closing the well) to prevent further cases.
If this were a propagated epidemic, interventions would focus on breaking the chain of transmission through measures like isolation, quarantine, and vaccination.

How to Approach the Question

First, analyze the keywords in the question stem: 'clustered cases' and 'contaminated well'.
Identify what each keyword signifies. 'Contaminated well' points to a common source of infection. 'Clustered cases' suggests the exposure happened at a single point in time.
Next, review the definitions of the options provided.
Match the pattern identified in the stem (single source, single exposure time) with the correct definition.
A 'point source' epidemic is defined by exposure to a single source at a single point in time, which perfectly matches the scenario.
Eliminate other options: 'propagated' is person-to-person, 'continuous source' is prolonged exposure, and the last option is a general definition, not a type.

Concept Tested & Keywords

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