Quarantine: duration: 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 · Quarantine: duration

Sample item

Contacts of a case of an infection are to be quarantined. The incubation period is 5 to 12 days (median 8 days) and the patient is infectious from 2 days before to 5 days after onset. Healthy contacts were last exposed on 1 March. Until what date should quarantine continue?

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

The answer and the reasoning

B. 13 March

Quarantine restricts the movement of healthy contacts for a period equal to the longest usual incubation period, counted from the last exposure. Here that is 12 days, so the date is 13 March. The infectious period of the patient determines isolation of the case, not the quarantine of contacts.

Option by option

  • A. 9 March

    This uses the median incubation period, which would release contacts who are still incubating the infection.

  • B. 13 March (correct)

    Correct. The longest incubation period of 12 days after 1 March ends on 13 March.

  • C. 6 March

    This uses the shortest incubation period, which would release most incubating contacts.

  • D. 18 March

    This adds the infectious period to the incubation period, mixing up isolation of the case with quarantine of contacts.

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.

More PSM questions

Questions about this PSM question

What is the answer to this PSM question?

The best answer is B, 13 March. Quarantine restricts the movement of healthy contacts for a period equal to the longest usual incubation period, counted from the last exposure.

Why is "9 March" not the answer?

This uses the median incubation period, which would release contacts who are still incubating the infection.

Why is "6 March" not the answer?

This uses the shortest incubation period, which would release most incubating contacts.

Why is "18 March" not the answer?

This adds the infectious period to the incubation period, mixing up isolation of the case with quarantine of contacts.

What concept does this question test?

It tests Quarantine: duration in PSM. Here that is 12 days, so the date is 13 March. The infectious period of the patient determines isolation of the case, not the quarantine of contacts.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. 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 Quarantine: duration?

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.