A 28-year-old traveller returning from sub-Saharan Africa presents with cyclical fever every 48 hours, severe headache, and altered consciousness. Peripheral blood smear shows small ring forms with multiple rings per RBC, banana-shaped gametocytes, and no stippling. Which plasmodium species is responsible?
- A Plasmodium falciparum ✓
- B Plasmodium vivax
- C Plasmodium malariae
- D Plasmodium ovale
Correct answer: A. Plasmodium falciparum
Explanation
Plasmodium falciparum characteristically shows multiple ring forms per RBC ('double chromatin dots', 'applique/accolé forms'), banana-shaped (crescent/sausage-shaped) gametocytes, and no Schüffner's dots. It causes tertian (48-hour) fever and severe/cerebral malaria. P. vivax and P. ovale show Schüffner's stippling and single rings. P. malariae produces quartan (72-hour) fever and 'band/rosette' forms. Banana-shaped gametocytes are pathognomonic of P. falciparum.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.