Communicable diseases: epidemic typhus vector: practice question

A PSM 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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PSM · Communicable diseases: epidemic typhus vector

Sample item

In an overcrowded flood-relief camp with poor hygiene, a refugee has headache, high fever and a rash that starts on the trunk and spreads outwards, sparing the face, palms and soles. Clothing seams are found to be infested. Which arthropod is the vector?

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

The answer and the reasoning

A. Body louse (Pediculus humanus corporis)

Epidemic typhus is caused by Rickettsia prowazekii and spread by the body louse, whose infected faeces are rubbed into the bite wound. It occurs where crowding, cold and poor hygiene favour lice. Delousing with insecticide and doxycycline treatment control outbreaks.

Option by option

  • A. Body louse (Pediculus humanus corporis) (correct)

    Correct. The body louse transmits Rickettsia prowazekii in crowded, unhygienic settings.

  • B. Soft tick (Ornithodoros)

    Soft ticks transmit endemic relapsing fever.

  • C. Trombiculid mite (Leptotrombidium)

    Trombiculid mites transmit scrub typhus.

  • D. Rat flea (Xenopsylla cheopis)

    The rat flea transmits plague and murine typhus.

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 PSM questions

Questions about this PSM question

What is the answer to this PSM question?

The best answer is A, Body louse (Pediculus humanus corporis). Epidemic typhus is caused by Rickettsia prowazekii and spread by the body louse, whose infected faeces are rubbed into the bite wound.

Why is "Soft tick (Ornithodoros)" not the answer?

Soft ticks transmit endemic relapsing fever.

Why is "Trombiculid mite (Leptotrombidium)" not the answer?

Trombiculid mites transmit scrub typhus.

Why is "Rat flea (Xenopsylla cheopis)" not the answer?

The rat flea transmits plague and murine typhus.

What concept does this question test?

It tests Communicable diseases: epidemic typhus vector in PSM. It occurs where crowding, cold and poor hygiene favour lice. Delousing with insecticide and doxycycline treatment control outbreaks.

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 Communicable diseases: epidemic typhus vector?

Practise biostatistics with small calculations until sensitivity, predictive values and risk measures are automatic. Then use the flashcards and the other PSM 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.