Which Plasmodium species is characterized by Schiiffner's dots in infected erythrocytes?

• A. P. knowlesi
• B. P. ovale
• C. P. falciparum
• D. P. malariae

Answer: (B)

Schüffner's dots are fine cytoplasmic stippling seen in red blood cells infected by certain malaria parasites. They are most characteristic of infections with Plasmodium vivax and Plasmodium ovale and are best seen on Giemsa-stained smears. Among the options, this finding points to Plasmodium ovale, since falciparum typically shows multiple tiny ring forms and other distinctive features, while malariae shows band-shaped trophozoites and rosette schizonts rather than cytoplasmic dots. Plasmodium knowlesi can resemble other species but Schüffner's dots are not a defining feature for it. So, the presence of Schüffner's dots aligns with Plasmodium ovale.