Epidemiology: practice question

A PSM question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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PSM · Epidemiology

Sample item

After a wedding feast, many guests develop gastroenteritis within a few hours of each other. What shape of epidemic curve is expected?

AA single sharp peak with a rapid fall, within one incubation periodBA prolonged plateau extending over many incubation periodsCSuccessive progressively higher peaks separated by one incubation periodDA flat line with a low constant number of cases

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

A. A single sharp peak with a rapid fall, within one incubation period

A common-source, point-exposure outbreak shows a sharp rise and fall, with all cases occurring within one incubation period of the single exposure. Propagated outbreaks show successive waves, and endemic disease shows a steady baseline.

Option by option

A. A single sharp peak with a rapid fall, within one incubation period (correct)
Correct. A single exposure produces a sharp single-peaked curve.
B. A prolonged plateau extending over many incubation periods
A prolonged plateau suggests continuous or repeated exposure to the source.
C. Successive progressively higher peaks separated by one incubation period
Successive rising peaks describe a propagated outbreak spreading person to person.
D. A flat line with a low constant number of cases
A flat, low line represents endemic disease rather than an outbreak.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this PSM question

What is the answer to this PSM question?

The best answer is A, A single sharp peak with a rapid fall, within one incubation period. A common-source, point-exposure outbreak shows a sharp rise and fall, with all cases occurring within one incubation period of the single exposure.

Why is "A prolonged plateau extending over many incubation periods" not the answer?

A prolonged plateau suggests continuous or repeated exposure to the source.

Why is "Successive progressively higher peaks separated by one incubation per…" not the answer?

Successive rising peaks describe a propagated outbreak spreading person to person.

Why is "A flat line with a low constant number of cases" not the answer?

A flat, low line represents endemic disease rather than an outbreak.

What concept does this question test?

It tests Epidemiology in PSM. Propagated outbreaks show successive waves, and endemic disease shows a steady baseline.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Epidemiology?

Practise biostatistics with small calculations until sensitivity, predictive values and risk measures are automatic. Then use the flashcards and the other PSM questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.