Virology: herpes simplex latency: 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: herpes simplex latency

Sample item

A woman has had several episodes of genital herpes, always at the same site on the buttock, between which the lesions disappear completely. Where does the virus remain latent in the interval?

ARegional lymph node B lymphocytesBBasal epithelial cells at the site of the lesionCAnterior horn cells of the spinal cordDSacral dorsal root ganglia

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

The answer and the reasoning

D. Sacral dorsal root ganglia

Herpes simplex virus travels by retrograde axonal transport to sensory ganglia and establishes latency in neurons. For genital herpes, this is the sacral dorsal root ganglia, while HSV-1 oral infection is latent in the trigeminal ganglion. Reactivation sends virus back along the same nerve to the skin at the original dermatome.

Option by option

A. Regional lymph node B lymphocytes
B lymphocytes are the latent site of Epstein-Barr virus, not herpes simplex virus.
B. Basal epithelial cells at the site of the lesion
Basal epithelial cells are cleared of virus between episodes and do not hold the latent genome.
C. Anterior horn cells of the spinal cord
Anterior horn cells are the target of poliovirus, and are not a site of herpes simplex latency.
D. Sacral dorsal root ganglia (correct)
Correct. The sacral sensory ganglia harbour the latent genome that reactivates in the same dermatome.

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 D, Sacral dorsal root ganglia. Herpes simplex virus travels by retrograde axonal transport to sensory ganglia and establishes latency in neurons.

Why is "Regional lymph node B lymphocytes" not the answer?

B lymphocytes are the latent site of Epstein-Barr virus, not herpes simplex virus.

Why is "Basal epithelial cells at the site of the lesion" not the answer?

Basal epithelial cells are cleared of virus between episodes and do not hold the latent genome.

Why is "Anterior horn cells of the spinal cord" not the answer?

Anterior horn cells are the target of poliovirus, and are not a site of herpes simplex latency.

What concept does this question test?

It tests Virology: herpes simplex latency in Microbiology. For genital herpes, this is the sacral dorsal root ganglia, while HSV-1 oral infection is latent in the trigeminal ganglion. Reactivation sends virus back along the same nerve to the skin at the original dermatome.

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: herpes simplex latency?

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.