Virology: mpox: practice question

A Microbiology 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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Microbiology · Virology: mpox

Sample item

A traveller has fever followed by a vesiculopustular rash that is at the same stage in all areas, with prominent tender cervical and inguinal lymphadenopathy. Which test best confirms the diagnosis?

APCR on a swab of the vesicle fluid or crustBBlood cultureCSerum IgG antibody aloneDTzanck smear alone

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

The answer and the reasoning

A. PCR on a swab of the vesicle fluid or crust

Mpox is caused by an orthopoxvirus and resembles smallpox, but lymphadenopathy is a distinguishing feature. Diagnosis rests on detecting viral DNA by PCR in lesion material, taken by swabbing vesicle fluid or collecting crusts. A Tzanck smear is non-specific and orthopoxvirus IgG is not reliable in a vaccinated or exposed population.

Option by option

A. PCR on a swab of the vesicle fluid or crust (correct)
Correct. Lesion PCR is sensitive and specific for mpox virus.
B. Blood culture
Blood culture is for bacterial infection and does not detect this virus.
C. Serum IgG antibody alone
IgG antibody cannot separate current from past infection or vaccination.
D. Tzanck smear alone
A Tzanck smear shows multinucleated giant cells in herpesvirus infection and is not specific.

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 Microbiology question

What is the answer to this Microbiology question?

The best answer is A, PCR on a swab of the vesicle fluid or crust. Mpox is caused by an orthopoxvirus and resembles smallpox, but lymphadenopathy is a distinguishing feature.

Why is "Blood culture" not the answer?

Blood culture is for bacterial infection and does not detect this virus.

Why is "Serum IgG antibody alone" not the answer?

IgG antibody cannot separate current from past infection or vaccination.

Why is "Tzanck smear alone" not the answer?

A Tzanck smear shows multinucleated giant cells in herpesvirus infection and is not specific.

What concept does this question test?

It tests Virology: mpox in Microbiology. Diagnosis rests on detecting viral DNA by PCR in lesion material, taken by swabbing vesicle fluid or collecting crusts. A Tzanck smear is non-specific and orthopoxvirus IgG is not reliable in a vaccinated or exposed population.

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 Virology: mpox?

Make a one-line identity card for each organism: shape and stain, defining test, toxin, disease and drug. Then use the flashcards and the other Microbiology 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.