Virology: HBV cccDNA persistence: 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: HBV cccDNA persistence

Sample item

A man with chronic hepatitis B has had undetectable serum HBV DNA on tenofovir for five years. After he stops the drug, viraemia returns within months. Which viral feature mainly explains the relapse?

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

The answer and the reasoning

B. Persistent nuclear cccDNA in hepatocytes

After entry, HBV converts its relaxed circular DNA into covalently closed circular DNA in the hepatocyte nucleus, where it acts as a stable minichromosome and template for viral RNAs. Polymerase inhibitors block reverse transcription but do not eliminate this reservoir, so stopping therapy lets replication resume.

Option by option

  • A. Latent provirus integrated in resting CD4 cells

    Latent proviral DNA in CD4 cells is the reservoir of HIV, not HBV.

  • B. Persistent nuclear cccDNA in hepatocytes (correct)

    Correct. Nucleoside analogues do not remove cccDNA, which re-seeds replication when drugs are stopped.

  • C. Universal selection of a resistant polymerase mutant

    Resistance to tenofovir is rare and does not occur in every patient.

  • D. Latent virus in sensory ganglia neurons

    Latency in sensory ganglia is a feature of herpes simplex and varicella-zoster viruses.

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 Microbiology questions

Questions about this Microbiology question

What is the answer to this Microbiology question?

The best answer is B, Persistent nuclear cccDNA in hepatocytes. After entry, HBV converts its relaxed circular DNA into covalently closed circular DNA in the hepatocyte nucleus, where it acts as a stable minichromosome and template for viral RNAs.

Why is "Latent provirus integrated in resting CD4 cells" not the answer?

Latent proviral DNA in CD4 cells is the reservoir of HIV, not HBV.

Why is "Universal selection of a resistant polymerase mutant" not the answer?

Resistance to tenofovir is rare and does not occur in every patient.

Why is "Latent virus in sensory ganglia neurons" not the answer?

Latency in sensory ganglia is a feature of herpes simplex and varicella-zoster viruses.

What concept does this question test?

It tests Virology: HBV cccDNA persistence in Microbiology. Polymerase inhibitors block reverse transcription but do not eliminate this reservoir, so stopping therapy lets replication resume.

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 Virology: HBV cccDNA persistence?

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.