Bacteriology: meningococcal chemoprophylaxis: 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 · Bacteriology: meningococcal chemoprophylaxis

Sample item

A 20-year-old hostel resident has meningococcal meningitis. His roommate, who is 21 years old and not pregnant, needs chemoprophylaxis to eliminate nasopharyngeal carriage. Which regimen is appropriate?

AOral penicillin V for 7 daysBRifampicin 600 mg twice daily for 2 daysCOral cephalexin for 7 daysDOral amoxicillin for 7 days

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

The answer and the reasoning

B. Rifampicin 600 mg twice daily for 2 days

Close contacts of invasive meningococcal disease should receive chemoprophylaxis because penicillin treats invasive disease but does not reliably clear carriage in the nasopharynx. Rifampicin for 2 days, a single oral dose of ciprofloxacin, or a single intramuscular dose of ceftriaxone are the standard options. Rifampicin turns body fluids orange and induces hepatic enzymes.

Option by option

A. Oral penicillin V for 7 days
Penicillin does not achieve adequate nasopharyngeal concentrations to clear carriage.
B. Rifampicin 600 mg twice daily for 2 days (correct)
Correct. Rifampicin reliably eradicates nasopharyngeal carriage.
C. Oral cephalexin for 7 days
Cephalexin is not a recommended agent and does not achieve reliable carriage eradication.
D. Oral amoxicillin for 7 days
Amoxicillin has the same limitation and is not a recommended prophylactic agent.

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 B, Rifampicin 600 mg twice daily for 2 days. Close contacts of invasive meningococcal disease should receive chemoprophylaxis because penicillin treats invasive disease but does not reliably clear carriage in the nasopharynx.

Why is "Oral penicillin V for 7 days" not the answer?

Penicillin does not achieve adequate nasopharyngeal concentrations to clear carriage.

Why is "Oral cephalexin for 7 days" not the answer?

Cephalexin is not a recommended agent and does not achieve reliable carriage eradication.

Why is "Oral amoxicillin for 7 days" not the answer?

Amoxicillin has the same limitation and is not a recommended prophylactic agent.

What concept does this question test?

It tests Bacteriology: meningococcal chemoprophylaxis in Microbiology. Rifampicin for 2 days, a single oral dose of ciprofloxacin, or a single intramuscular dose of ceftriaxone are the standard options. Rifampicin turns body fluids orange and induces hepatic enzymes.

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 Bacteriology: meningococcal chemoprophylaxis?

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.