A patient treated successfully for Plasmodium vivax malaria returns four months later with vivax parasitaemia of the identical genotype. The mechanism of this recurrence is:
- A Activation of hypnozoites persisting in hepatocytes ✓
- B Reinfection from a fresh mosquito bite
- C Recrudescence from persisting blood-stage parasites
- D Maturation of sequestered gametocytes in the bone marrow
Correct answer: A. Activation of hypnozoites persisting in hepatocytes
Explanation
P. vivax and P. ovale produce dormant hypnozoites in hepatocytes; their reactivation weeks to months after clearance of the blood infection causes true relapse with the same genotype. Recrudescence is reappearance of parasites in the blood because treatment failed to clear them, seen classically with falciparum, which has no exoerythrocytic dormant stage. Reinfection produces a genotype unrelated to the original isolate.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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