A patient from Assam presents with fever and is found to have thick blood films showing 'banana-shaped' gametocytes. Thin films reveal infected erythrocytes with 'appliqué (accolé) forms' and multiple ring forms per cell. PCR confirms the species. Which diagnostic marker distinguishes this species from P. vivax in antigen-based rapid diagnostic tests?

• A Lactate dehydrogenase (pLDH) pan-malarial antigen
• B Aldolase pan-malarial antigen
• C PfEMP-1 surface antigen
• D Histidine-rich protein-2 (HRP-2) ✓

Explanation

P. falciparum-specific rapid diagnostic tests (RDTs) detect histidine-rich protein-2 (HRP-2), which is exclusively produced by P. falciparum. HRP-2 may remain positive for several weeks after treatment due to antigen persistence. Pan-malarial pLDH and aldolase detect all Plasmodium species and cannot distinguish falciparum from vivax. PfEMP-1 is a cytoadherence protein mediating sequestration, not a standard RDT target.

Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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