Parasitology: congenital toxoplasmosis timing: 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: congenital toxoplasmosis timing

Sample item

A woman acquires primary Toxoplasma infection during pregnancy. Which statement about vertical transmission is correct?

ARisk is highest in the first trimester and mildest thenBTransmission occurs only if infected before conceptionCRisk rises with gestation, but early infection is more severeDRisk and severity are the same in every trimester

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

The answer and the reasoning

C. Risk rises with gestation, but early infection is more severe

Transplacental transmission becomes more frequent as pregnancy advances, but infection acquired early, when transmission is less likely, causes the most severe fetal disease. Late infections are transmitted often but are usually subclinical at birth.

Option by option

A. Risk is highest in the first trimester and mildest then
The first trimester has the lowest transmission rate but the most severe fetal damage.
B. Transmission occurs only if infected before conception
Infection must be acquired during pregnancy for congenital transmission; past immunity protects the fetus.
C. Risk rises with gestation, but early infection is more severe (correct)
Correct. Transmission rises with gestational age while severity falls.
D. Risk and severity are the same in every trimester
Both transmission rate and severity differ with gestational age.

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, Risk rises with gestation, but early infection is more severe. Transplacental transmission becomes more frequent as pregnancy advances, but infection acquired early, when transmission is less likely, causes the most severe fetal disease.

Why is "Risk is highest in the first trimester and mildest then" not the answer?

The first trimester has the lowest transmission rate but the most severe fetal damage.

Why is "Transmission occurs only if infected before conception" not the answer?

Infection must be acquired during pregnancy for congenital transmission; past immunity protects the fetus.

Why is "Risk and severity are the same in every trimester" not the answer?

Both transmission rate and severity differ with gestational age.

What concept does this question test?

It tests Parasitology: congenital toxoplasmosis timing in Microbiology. Late infections are transmitted often but are usually subclinical at birth.

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: congenital toxoplasmosis timing?

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.