A 35-year-old male returning from sub-Saharan Africa has daily fever, jaundice, and hemoglobin 7 g/dL. Peripheral blood smear shows parasitized RBCs enlarged to twice normal size, Schüffner's dots, and amoeboid trophozoites. Which Plasmodium species is responsible?
- A Plasmodium falciparum
- B Plasmodium malariae
- C Plasmodium vivax ✓
- D Plasmodium ovale
Correct answer: C. Plasmodium vivax
Explanation
P. vivax causes enlargement of infected RBCs, prominent Schüffner's stippling, and amoeboid (irregular, pseudopod-like) trophozoites — all classic distinguishing features. P. falciparum does not enlarge RBCs and shows only ring forms and banana-shaped gametocytes without Schüffner's dots. P. malariae produces rosette schizonts in normal-sized RBCs with Ziemann's stippling. P. ovale also has Schüffner's dots and fimbriated RBCs but is less common in sub-Saharan Africa compared to P. vivax.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.