Which Plasmodium species is associated with intracellular crescent-shaped gametocytes?

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

Answer: (A)

The main idea is the distinctive appearance of malaria parasite gametocytes on a blood smear. Plasmodium falciparum produces intracellular, banana- or crescent-shaped gametocytes that remain inside red blood cells, and this morphology is a hallmark used to identify this species. In contrast, gametocytes of the other human malaria parasites are typically not crescent-shaped: vivax and ovale have larger, round-to-oval gametocytes seen in enlarged red cells, often with other pigment features, while malariae gametocytes are smaller and more compact without a crescent form. So seeing intracellular crescent-shaped gametocytes points to Plasmodium falciparum.