A 32-year-old returns from a forested area in Odisha with fever for 3 days, headache, and mild confusion. Blood smear shows ring forms with double chromatin dots and banana-shaped gametocytes. Which characteristic of the causative organism best explains the cerebral manifestations?

• A Production of toxin that directly damages the blood-brain barrier
• B Cytoadherence of infected RBCs to cerebral microvascular endothelium via PfEMP1 ✓
• C Invasion of neurons directly by merozoites
• D Hypersplenism causing sequestration of parasitised cells in splenic sinusoids

Explanation

Plasmodium falciparum causes cerebral malaria through cytoadherence: infected RBCs express PfEMP1 (Plasmodium falciparum erythrocyte membrane protein 1) on their surface, which binds to ICAM-1, CD36, and other receptors on cerebral microvascular endothelium, causing sequestration and impaired microvascular flow. This leads to cerebral ischaemia, inflammation, and altered consciousness. The banana-shaped gametocyte is pathognomonic for P. falciparum. P. falciparum does not invade neurons; spleen sequestration is a feature of P. vivax rosetting.

Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.