Which of the following is NOT true regarding a point source epidemic?

Appeared in: RML 2023

Explanation

This statement is false because a point-source epidemic affects the population that was exposed to the common source, which is not limited to a specific age group like children.
The distribution of cases by person (age, sex, etc.) depends entirely on the pattern of exposure.
For example, an outbreak from contaminated food at a company picnic would affect employees of various ages, not just children.

Option A: This is a true statement. In a point-source epidemic, the exposure is from a single source and is not transmitted from person to person, so secondary waves of infection do not occur.
Option B: This is a true statement. All cases in a point-source epidemic develop within one incubation period of the disease after the single, brief exposure.
Option C: This is a true statement. A key feature of a point-source epidemic is the 'explosive' onset, with a sudden and rapid increase in the number of cases because everyone is exposed at roughly the same time.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Characteristics of a point-source epidemic as background academic context rather than a clinical decision trigger.
Identifying the type of epidemic is crucial for public health nurses and epidemiologists to implement effective control measures.
In a point-source epidemic, the primary intervention is to identify and eliminate the common source (e.g., recall contaminated food, treat a contaminated water supply).
In a propagated epidemic, interventions focus on breaking the chain of transmission (e.g., quarantine, vaccination, health education).

How to Approach the Question

First, identify that the question is a 'negative' question, asking for the statement that is NOT true.
Next, recall the definition and key characteristics of a point-source epidemic: a single, common exposure; an explosive onset of cases; all cases within one incubation period; and no person-to-person spread.
Evaluate each option against these characteristics.
Option A ('No secondary wave') is a true feature.
Option B ('Occurs within a specific period') is a true feature (one incubation period).
Option C ('All cases occur abruptly') is a true feature (explosive onset).

Concept Tested & Keywords

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E6 Parks TextBook of Preventive & Social Medicine part 1 — Subpart A (pp 26-201 of 604) p. 57-59

Practise the full RML 2023

Attempt every question from this paper in a timed mock, then review the full solution for each one.