Schizonts, merozoites, and phagocytosis in falciparum malaria.

Two Nigerian siblings, ages 10 and 4 years, respectively, were infected with Plasmodium falciparum and were admitted to the hospital on the same day. The younger child died on the day of admission, but the older child survived. The peripheral blood smears of the younger patient showed the ring forms, schizonts, free merozoites, and phagocytosis of malarial parasites by both monocytes and polymorphonuclear leukocytes, whereas the smear from the older patient revealed only ring forms. The prognostic significance of this unusual observation and the host factors that affect the survival of the patients are discussed. This is the first documented case in which phagocytosis of malarial parasites by polymorphonuclear leukocytes is observed.