[Elizabeth_Zeibig]_Clinical_Parasitology__A_Practi(z-lib.org)

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CHAPTER 12 Artifacts and Confusers
C H A P T E R
12
Artifacts and Confusers
Charity Accurso and Elizabeth Zeibig
W H A T ’ S A H E A D
Focusing In
White Blood Cells
Pollen Grains
Vegetable Cells
Vegetable Spirals
Charcot-Leyden Crystals
Yeast
Plant Hair
Plant Material
Epithelial Cells
Fungal Elements
Starch Cells
Clumped or Fused Platelets
Stain Precipitate
Red Cell Abnormalities
Looking Back
L E A R N I N G O B J E C T I V E S
On completion of this chapter and review of
its figures and corresponding photomicrographs,
the successful learner will be able to:
12-1. Differentiate the artifacts and confusers
discussed from parasites based on their key
characteristics.
12-2. State the derivation and significance of
Charcot-Leyden crystals, when present.
12-3. Given a diagram of an artifact or confuser,
correctly name it as one, and not as a
parasite.
12-4. Given prepared laboratory specimens, and
with the assistance of this manual, the
learner will be able to:
Differentiate the artifact and confusers
discussed from parasites.
FOCUSING IN
There are a number of structures that closely
resemble parasites but in reality are not. These
structures, termed artifacts and confusers, are
found primarily in stool and blood samples. Such
stool artifacts and confusers may be the result of
disease processes, medications, and/or dietary
habits, such as those seen in Figure 12-1. The
presence of free-living organisms in stool caused
by specimen contact with water, sewage, or
soil may often cause confusion. Artifacts and
confusers, such as stain precipitate, red blood cell
abnormalities, including Howell-Jolly bodies,
and the clumping of platelets, may be seen on
blood smears.
In addition to the common artifacts and confusers
mentioned in this chapter, others may be
seen in samples submitted for parasite study.
Free-living amebae, flagellates, ciliates, and nematodes
are some of these confusers. Accidental
ingestion of parasite forms in which humans are
not part of their life cycle may also yield confusers.
Fourteen of the most common artifacts and
286 Copyright © 2013 by Saunders, an imprint of Elsevier Inc.