A thick blood smear from a patient with suspected malaria shows rings that occupy more than one-fifth of the RBC diameter, multiple rings per RBC, 'applique' (accolé) forms, and banana-shaped gametocytes. The causative species is:
- A Plasmodium vivax
- B Plasmodium malariae
- C Plasmodium falciparum ✓
- D Plasmodium ovale
Correct answer: C. Plasmodium falciparum
Explanation
Plasmodium falciparum characteristically shows: rings occupying >1/5 RBC diameter (large ring forms), multiple ring infections per RBC, applique or accolé forms (rings applied to the outer margin of RBC), and banana/crescent-shaped (falciform) gametocytes. RBCs are not enlarged. P. vivax shows enlarged RBCs with Schüffner's dots. P. malariae has 'band-form' trophozoites in normal-sized RBCs. P. ovale has fimbriated/oval RBCs with Schüffner's dots.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.