A 32-year-old traveller returning from sub-Saharan Africa presents with daily fever, haemoglobinuria (blackwater fever), and severe haemolytic anaemia. Peripheral blood smear shows ring forms with appliqué (accolé) position and rare but characteristic banana-shaped gametocytes. Which Plasmodium species is responsible?

• A Plasmodium vivax
• B Plasmodium malariae
• C Plasmodium ovale
• D Plasmodium falciparum ✓

Explanation

P. falciparum produces banana/crescent-shaped (falciform) gametocytes, which are pathognomonic on smear. The appliqué (accolé) position of ring forms is also characteristic of P. falciparum. Blackwater fever — massive haemolysis causing haemoglobinuria — is a severe complication of P. falciparum. P. vivax and P. ovale have enlarged erythrocytes with Schüffner's dots; P. malariae has band-form trophozoites and causes quartan fever.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.