Virology: norovirus outbreak control: 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: norovirus outbreak control

Sample item

On a cruise ship, many passengers develop sudden vomiting and watery diarrhoea 24 to 36 hours after a buffet, with recovery within 3 days. Which measure is most important for controlling spread?

AAlcohol-based hand rub alone, as it reliably inactivates this agentBIntravenous acyclovir for those with vomitingCHand washing with soap and water, and cleaning surfaces with chlorine-based disinfectantDEmpirical ciprofloxacin for all passengers

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

The answer and the reasoning

C. Hand washing with soap and water, and cleaning surfaces with chlorine-based disinfectant

Norovirus is a non-enveloped calicivirus with a low infectious dose and prolonged environmental survival. Alcohol hand rubs are less reliable against non-enveloped viruses, so washing with soap and water and chlorine-based cleaning are advised. Treatment is rehydration, and diagnosis is by stool RT-PCR.

Option by option

A. Alcohol-based hand rub alone, as it reliably inactivates this agent
Alcohol rubs are less reliable against non-enveloped viruses such as norovirus.
B. Intravenous acyclovir for those with vomiting
Acyclovir acts on herpesviruses and has no role in norovirus infection.
C. Hand washing with soap and water, and cleaning surfaces with chlorine-based disinfectant (correct)
Correct. Mechanical washing and chlorine disinfection control this resistant non-enveloped virus.
D. Empirical ciprofloxacin for all passengers
Antibacterials have no effect on a viral gastroenteritis.

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 C, Hand washing with soap and water, and cleaning surfaces with chlorine-based disinfectant. Norovirus is a non-enveloped calicivirus with a low infectious dose and prolonged environmental survival.

Why is "Alcohol-based hand rub alone, as it reliably inactivates this agent" not the answer?

Alcohol rubs are less reliable against non-enveloped viruses such as norovirus.

Why is "Intravenous acyclovir for those with vomiting" not the answer?

Acyclovir acts on herpesviruses and has no role in norovirus infection.

Why is "Empirical ciprofloxacin for all passengers" not the answer?

Antibacterials have no effect on a viral gastroenteritis.

What concept does this question test?

It tests Virology: norovirus outbreak control in Microbiology. Alcohol hand rubs are less reliable against non-enveloped viruses, so washing with soap and water and chlorine-based cleaning are advised. Treatment is rehydration, and diagnosis is by stool RT-PCR.

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: norovirus outbreak control?

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.