[Elizabeth_Zeibig]_Clinical_Parasitology__A_Practi(z-lib.org)

CHAPTER 8 The Nematodes
217
8-8. Differences in which of the following
morphologic forms serve as criteria necessary
to speciate the hookworms? (Objective
8-12)
A. Eggs
B. Rhabditiform larvae
C. Encysted larvae
D. Adult worms
8-9. Match the term (column A) with its key
word or phrase definition (column B).
(Objective 8-1)
Column A
Column B
A. Gravid 1. Presence of an
outer albuminous
coating
B. Embryonated 2. Surface covering
C. Cuticle 3. Fertilized
Column A
Column B
D. Parthenogenic 4. Absence of an
outer albuminous
coating
E. Decorticated 5. Pregnant
6. Unfertilized
7. Formation
without
fertilization
8-10. Which of these parasites are contracted via
skin penetration? (Objective 8-6)
A. Enterobius, Necator, Dracunculus
B. Ascaris, Trichinella, Ancylostoma
C. Trichuris, Strongyloides, Enterobius
D. Ancylostoma, Strongyloides, Necator
CASE STUDY 8-2
UNDER THE MICROSCOPE
Paz, a 32-year-old woman originally from the Philippines,
emigrated to the United States 2 years ago. She has since
married and, at the time of admission, was pregnant with
her first child. Economic restraints prevented the woman
from seeking prenatal care. At the onset of labor, Paz was
rushed to the local emergency room. During her labor, Paz
told the nurse that she felt nauseous and thought that she
was going to be sick. Paz then proceeded to cough up a
large worm. The nurse placed the worm in a sterile urine
cup and had it promptly sent to the laboratory for analysis.
After the delivery of her child, a stool sample for parasite
study was ordered, collected, and sent to the laboratory. The
physician checked the baby and found him to be perfectly
healthy.
Once the worm (as seen in the figure) arrived in the laboratory,
the clinical laboratorian on duty observed it under a
dissecting microscope and noted that the worm was pregnant.
The worm measured 30 cm in length and had the shape
and thickness of a lead pencil. The worm was creamy white
and possessed fine circular striations around the cuticle.
On receipt, the stool sample was promptly processed for
parasite examination. Oval forms (as seen in the figure),
which measured 60 by 40 µm, were observed in both the
saline and iodine wet preparations. A trichrome stain was
later performed and revealed the same organisms.
Questions and Issues for Consideration
1. State the scientific name and morphologic forms of the
parasite you suspect to be present in this case. (Objectives
8-10C and 8-11A)
2. What is the common name associated with the parasite
present? (Objective 8-11A)
3. Construct a life cycle for the parasite present in this case.
(Objective 8-11C)
4. Which treatment option(s) and prevention and control
strategies could be put into place to stop this parasite
from replicating? (Objective 8-11D)