[Elizabeth_Zeibig]_Clinical_Parasitology__A_Practi(z-lib.org)

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CHAPTER 11 The Trematodes
elongated. Comparison drawings of the trematode
eggs and adults are provided at the end
of this chapter as a reference guide for study and
as an aid in identifying organisms in patient
specimens.
TEST YOUR KNOWLEDGE!
11-1. Trematodes that mature in the lung and
produce eggs that appear in the sputum
are most probably which of the following?
(Objective 11-5)
A. Fasciolopsis buski
B. Schistosoma japonicum
C. Paragonimus westermani
D. Clonorchis sinensis
11-2. Consumption of the infective larval stage
encysted on aquatic plants that have not
been cooked results in infection with:
(Objective 11-5)
A. Clonorchis sinensis
B. Fasciola hepatica
C. Heterophyes heterophyes
D. Paragonimus westermani
11-3. The largest fluke infecting humans measuring
as much as 5 cm in length is which
of the following? (Objective 11-9)
A. Fasciolopsis buski
B. Fasciola hepatica
C. Paragonimus westermani
D. Clonorchis sinensis
11-4. A schistosoma egg with a terminal spine
would be most likely found in which of
the following? (Objective 11-9)
A. Feces
B. Bile
C. Sputum
D. Urine
11-5. The infective form of Schistosoma
mansoni is which of the following?
(Objective 11-5)
A. Cercaria swimming in water
B. Metacercaria on or in fish
C. Metacercaria encysted on water
chestnuts or vegetables
D. Cercaria on water chestnuts, bamboo
shoots, or vegetables
11-6. In the life cycle of hermaphroditic flukes,
the infective stage for the snail is which
of the following? (Objective 11-5)
A. Cercaria
B. Miracidium
C. Metacercaria
D. Redia
11-7. The adult form of the sheep liver fluke
produces large, ovoid, unembryonated
eggs with a yellowish-brown shell and an
inconspicuous operculum. These eggs are
morphologically most similar to which of
the following? Objective 10-9)
A. Fasciola hepatica
B. Fasciolopsis buski
C. Clonorchis sinensis
D. Paragonimus westermani
11-8. The incidence of small, yellowish, oval,
operculated eggs with a short, commalike
extension of the shell opposite the
operculum increased markedly in stools
examined in the United States with the
influx of refugees from Vietnam and
nearby countries. Although not transmitted
in the United States, human infection
in endemic areas is acquired by which of
the following? (Objective 11-5)
A. Consumption of infected water
vegetation
B. Direct larval penetration of human
skin
C. Eating infected crabs or crayfish
D. Ingestion of infected fresh water
fish
11-9. A child visited his grandparents in rural
Egypt for a summer. While there, he
played in irrigation ditches and developed
salmonellosis. Blood cultures were
positive for Salmonella and a stool
examination revealed eggs of a parasite
common to that part of the world. The
egg would appear as which of the following?
(Objective 11-10A)
A. Large (80 × 140 µm), with an
operculum
B. Oval (40 × 48 µm), with a mammillated
coat