[Elizabeth_Zeibig]_Clinical_Parasitology__A_Practi(z-lib.org)

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APPENDIX D Answers to Test Your Knowledge (Review Questions)
1-8. (1) When parasite is in or on the human
body: Provides information about the
method of diagnosis, symptomatology,
pathology and selection of appropriate
antiparasitic medication.
(2) When parasite is independent of the
human body: Provides information
about epidemiology, prevention, and
control.
1-9. E (A, B, C, and D)
1-10. E (C and D)
1-11. The three groups of clinically significant
parasites areas follows: (1) Protozoa,
single-celled parasites; (2) Metazoa, multicellular
worms (helminths); and Animalia,
arthropods.
1-12. Possible prevention and control strategies
include the following: (1) practicing
good hygiene and sanitation practices;
(2) protecting picnic food from flies; (3)
proper handling and preparation of food;
and (4) educating at-risk individuals
regarding the proper use of insecticides
and other chemicals.
1-13. Any reasonable informational flyer is considered
acceptable; follow your instructor’s
guidelines and requirements for
completion. Creativity is encouraged.
Keep the audience in mind and use wording
that the audience will understand.
1-14. Any reasonable generic life cycle is considered
acceptable; the use of illustrations
and key words and phrases is
encouraged. Follow your instructor’s
guidelines and requirements for completion;
creativity is encouraged. It is important
that two life cycle phases (those that
occur when the parasite is in or on the
human body and independently from the
human body) are clearly distinguished
and delineated.
CHAPTER 2
2-1. B
2-2. C
2-3. B
2-4. C
2-5. True.
2-6. The purpose of the ocular micrometer is
to measure objects accurately under the
microscope. It must be calibrated to
determine the number of microns in the
units that make up the ocular scale.
2-7. It is acceptable to eliminate the direct wet
prep examination on a specimen that
is received in fixative. The main purpose
of the direct wet prep examination is
to detect the motility of trophozoites.
Because fixatives kill the trophozoites, no
motility will be observed.
2-8. The zinc sulfate flotation procedure does
yield a cleaner microscopic preparation;
however, some parasites will not be
detected with this method. Large helminth
eggs and eggs that have an operculum
will not float and will be missed.
Thus, most laboratory technicians prefer
the use of the sedimentation technique
because it results in a better recovery.
2-9. The specific gravity of the zinc sulfate
solution must be 1.18 to 1.20 to recover
the parasites in the specimen. If the specific
gravity is not within this range,
recovery will not be optimal.
2-10. The permanent stained smear allows the
technologist to observe more detailed
features of protozoa. In addition, it
allows for detection of protozoan trophozoites
that are not usually recovered
in the concentration procedure. Dientamoeba
fragilis is an example of a parasite
that will only be detected in the
stained smear because it only has a trophozoite
stage.
2-11. Rapid stool screens detect antigens to
specific protozoa in a stool sample. They
are available for Cryptosporidium spp.,
Giardia intestinalis, Entamoeba histolytica,
and Entamoeba histolytica–Entamoeba
dispar group. These methods do
not detect tapeworms; therefore, this test
request is inappropriate. As tests become
available in parasitology, it is important