Parasitology: transfusion-transmitted malaria: 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 · Parasitology: transfusion-transmitted malaria

Sample item

A patient develops fever with chills nine days after receiving a unit of blood from a donor who had lived in an endemic area, and the smear shows Plasmodium vivax. Which statement about this infection is correct?

AThere is no liver stage, so relapse does not occurBThe incubation period is longer than after a mosquito biteCHypnozoites form in hepatocytes and cause later relapseDSporozoites in donated blood invade the recipient's hepatocytes

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

The answer and the reasoning

A. There is no liver stage, so relapse does not occur

Blood-borne (induced) malaria bypasses the mosquito and liver phases because only erythrocytic forms are transferred. The incubation is short and there are no hypnozoites, so relapse does not occur and primaquine radical cure is not needed.

Option by option

A. There is no liver stage, so relapse does not occur (correct)
Correct. Only erythrocytic parasites are transferred, so there is no exo-erythrocytic stage and no relapse.
B. The incubation period is longer than after a mosquito bite
Induced malaria has a shorter incubation because the pre-erythrocytic phase is skipped.
C. Hypnozoites form in hepatocytes and cause later relapse
Hypnozoites arise only after sporozoite infection of the liver, which has not occurred here.
D. Sporozoites in donated blood invade the recipient's hepatocytes
Donated blood contains blood-stage parasites, not sporozoites.

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 A, There is no liver stage, so relapse does not occur. Blood-borne (induced) malaria bypasses the mosquito and liver phases because only erythrocytic forms are transferred.

Why is "The incubation period is longer than after a mosquito bite" not the answer?

Induced malaria has a shorter incubation because the pre-erythrocytic phase is skipped.

Why is "Hypnozoites form in hepatocytes and cause later relapse" not the answer?

Hypnozoites arise only after sporozoite infection of the liver, which has not occurred here.

Why is "Sporozoites in donated blood invade the recipient's hepatocytes" not the answer?

Donated blood contains blood-stage parasites, not sporozoites.

What concept does this question test?

It tests Parasitology: transfusion-transmitted malaria in Microbiology. The incubation is short and there are no hypnozoites, so relapse does not occur and primaquine radical cure is not needed.

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 Parasitology: transfusion-transmitted malaria?

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.