[Elizabeth_Zeibig]_Clinical_Parasitology__A_Practi(z-lib.org)

CHAPTER 6 Select Sporozoa: Plasmodium and Babesia
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b
a
A
B
c
C
D
FIGURE 6-7 Plasmodium falciparum composite consisting
of the following. A, Ring form with double chromatin.
B, ring form (a), schizont (b), and stain precipitate (c).
C, Immature schizont. D, Developing gametocyte. E, Mature
macrogametocyte (Giemsa stain, ×1000).
E
Black pigment surrounding the chromatin may
also be visible.
Other Morphologic Characteristics. P. falciparum
may infect RBCs at any age. However,
young infected cells do not enlarge and become
distorted, as they do when infected with P. vivax
or P. ovale. The morphologic forms of P. falciparum
do not contain Schüffner’s dots or Ziemann’s
dots. Rather, these growth stages may
contain dark-staining, irregular to comma-shaped
cytoplasmic dots called Maurer’s dots, a feature
that when present, may be helpful in differentiating
the specific malarial species.
Laboratory Diagnosis
Peripheral blood smears from patients suffering
with a mild to moderate P. falciparum infection
typically reveal only the ring forms and gametocyte
forms. The trophozoites and schizonts are