Communicable diseases: chikungunya versus dengue: 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: chikungunya versus dengue

Sample item

In the post-monsoon season in a city with abundant Aedes breeding, an adult has sudden high fever, a maculopapular rash and severe symmetrical pain and swelling of the small joints of the hands. Platelets are normal and there is no plasma leakage. Which diagnosis is most likely?

AChikungunyaBLeptospirosisCScrub typhusDDengue haemorrhagic fever

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

The answer and the reasoning

A. Chikungunya

Chikungunya is an Aedes-borne alphavirus infection in which incapacitating polyarthralgia, often persisting for weeks, dominates the picture. Dengue is characterised by thrombocytopenia, rising haematocrit and plasma leakage, which are absent here. Control relies mainly on vector control.

Option by option

A. Chikungunya (correct)
Correct. Severe small joint arthritis with fever and rash, without plasma leakage, points to chikungunya.
B. Leptospirosis
Leptospirosis presents with conjunctival suffusion, jaundice and renal involvement, not joint swelling.
C. Scrub typhus
Scrub typhus presents with an eschar and lymphadenopathy after exposure to scrub vegetation.
D. Dengue haemorrhagic fever
Dengue haemorrhagic fever is defined by thrombocytopenia and plasma leakage, which are absent.

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 PSM question

What is the answer to this PSM question?

The best answer is A, Chikungunya. Chikungunya is an Aedes-borne alphavirus infection in which incapacitating polyarthralgia, often persisting for weeks, dominates the picture.

Why is "Leptospirosis" not the answer?

Leptospirosis presents with conjunctival suffusion, jaundice and renal involvement, not joint swelling.

Why is "Scrub typhus" not the answer?

Scrub typhus presents with an eschar and lymphadenopathy after exposure to scrub vegetation.

Why is "Dengue haemorrhagic fever" not the answer?

Dengue haemorrhagic fever is defined by thrombocytopenia and plasma leakage, which are absent.

What concept does this question test?

It tests Communicable diseases: chikungunya versus dengue in PSM. Dengue is characterised by thrombocytopenia, rising haematocrit and plasma leakage, which are absent here. Control relies mainly on vector control.

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: chikungunya versus dengue?

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.