Infectious disease 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 · Infectious disease epidemiology

Sample item

What does a basic reproduction number above one generally imply in a fully susceptible population?

AThe infection cannot spreadBTransmission can potentially expandCVaccination is impossibleDEvery case will die

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

The answer and the reasoning

B. Transmission can potentially expand

A basic reproduction number greater than one means each case generates, on average, more than one secondary case in a fully susceptible population, allowing sustained spread unless control measures or immunity reduce transmission.

Option by option

A. The infection cannot spread
An infection with R0 above one can spread without control.
B. Transmission can potentially expand (correct)
Correct: R0 above one permits growth of transmission chains.
C. Vaccination is impossible
Vaccination feasibility is independent of the numerical definition of R0.
D. Every case will die
R0 measures transmission potential, not fatality.

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 B, Transmission can potentially expand. A basic reproduction number greater than one means each case generates, on average, more than one secondary case in a fully susceptible population, allowing sustained spread unless control measures or immunity reduce transmission.

Why is "The infection cannot spread" not the answer?

An infection with R0 above one can spread without control.

Why is "Vaccination is impossible" not the answer?

Vaccination feasibility is independent of the numerical definition of R0.

Why is "Every case will die" not the answer?

R0 measures transmission potential, not fatality.

What concept does this question test?

It tests Infectious disease epidemiology in PSM. The correct option holds because: Correct: R0 above one permits growth of transmission chains.

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 Infectious disease 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.