[Elizabeth_Zeibig]_Clinical_Parasitology__A_Practi(z-lib.org)

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CHAPTER 7 Miscellaneous Protozoa
common name, and morphologic form,
with justification.
B. Identify the diseases and conditions
associated with the responsible parasite
C. Construct a life cycle associated with
each organism present that includes
corresponding epidemiology, route of
transmission, infective stage, and
diagnostic stage.
D. Propose each of the following related to
stopping and preventing further parasite
infections:
1. Treatment options
2. Prevention and control plan
E. Determine the specimen(s) of choice and
alternative specimen types, when
appropriate, as well as appropriate
laboratory diagnostic techniques for the
recovery of each responsible parasite.
F. Recognize sources of error including
but not limited to those involved in
specimen collection, processing, and
testing and propose solutions to remedy
them.
G. Interpret laboratory data, determine
specific follow-up tests to be done, and
predict the results of those identified
tests.
H. Determine additional morphologic
forms, where appropriate, that may also
be detected in clinical specimens.
7-11 Identify, compare, and contrast the
similarities and differences among the
parasites discussed in this and the other
chapters in this text.
7-12. Describe standard, immunologic, and new
laboratory diagnostic approaches for the
recovery of the miscellaneous Protozoa in
clinical specimens.
7-13. Given prepared laboratory specimens, and
with the assistance of this manual, the
learner will be able to:
A. Differentiate the protozoan organisms
from artifacts and other parasites.
B. Correctly name each protozoan parasite
based on its key characteristic
structure(s).
CASE STUDY 7-1
UNDER THE MICROSCOPE
Joseph, a 29-year old man, went to a local health clinic
with complaints of intermittent diarrhea for a few months
and trouble sleeping. A stool specimen was collected and
preserved in 10% formalin and PVA. An O&P examination
was performed, along with a permanent trichrome stain.
The stain revealed the organism shown below that measured
10 µm in diameter, with a large, centrally located
vacuole and small red nuclei within the peripheral ring of
cytoplasm.
Questions and Issues for Consideration
1. What parasite do you suspect, and why? (Objectives
7-10A)
2. Why do false-negative results sometime occur with this
organism? (Objective 7-10F)
3. How does the organism reproduce? (Objective 7-10C)
4. Describe the controversy surrounding the classification
of this organism. (Objective 7-3)
5. Discuss treatment and prevention measures. (Objective
7-10D)
Size range: 5-32 m
Average size: 7-10 m