[Elizabeth_Zeibig]_Clinical_Parasitology__A_Practi(z-lib.org)

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CHAPTER 10 The Cestodes
proximal part of the jejunum, the patient is at
risk for developing vitamin B 12 deficiency. This
condition mimics that of pernicious anemia.
Inhabitants of select areas, such as Finland,
appear to be at higher risk for contracting this
parasite-induced condition. Some of them also
appear to be inherently predisposed to contracting
pernicious anemia. This is important because
it suggests that otherwise healthy patients infected
with D. latum appear not to exhibit excessive
symptoms, as might be expected considering the
predisposition and mimicry of symptoms noted
earlier.
treatment of choice. Praziquantel has also proven
effective against the sparganum.
Quick Quiz! 10-16
The egg of D. latum is unique among the cestodes in
that it contains which of the following? (Objective
10-10A)
A. An operculum and terminal knob
B. Radial striations and oncosphere
C. An operculum and lateral spine
D. A ciliated rhabditiform larva
Treatment
The drugs of choice for the treatment of D. latum
infections are praziquantel and niclosamide, if
available.
Prevention and Control
There are three primary prevention and control
measures that may be initiated to halt the spread
of D. latum. These include proper human fecal
disposal, avoidance of eating raw or undercooked
fish, and thorough cooking of all fish
before consumption.
Notes of Interest and New Trends
Humans have been known to suffer from sparganosis.
This condition results from ingesting the
procercoid larvae of D. latum as well as that of
other related Diphyllobothrium species. There
are two primary routes whereby humans can
contract this form of the parasite, water contaminated
with infected copepods and medicines contaminated
with infected animal by-products. The
formation of a sparganum (infected subcutaneous
tissue often described as white, wrinkled,
and ribbon-shaped) typically results. It is interesting
to note that in the life cycle of certain
species, humans serve as the intermediate host
for the parasite. In that of other species, the life
cycle ceases once it is consumed by a human.
Surgical removal of the sparganum is the
Quick Quiz! 10-17
Which of the following associations is correct for D.
latum? (Objective 10-5)
A. Snail-coracidium
B. Copepod-procercoid
C. Fish-cysticercus
D. Beetle-pleurocercoid
Quick Quiz! 10-18
The primary pathology associated with a D. latum
infection is which of the following? (Objective 10-6)
A. Eosinophilic pneumonitis
B. Vitamin D deficiency
C. Vitamin B 12 deficiency
D. Fat malabsorption
Echinococcus granulosus
(eh-kigh”no-kock’us/gran-yoo-lo’sus)
Common names: Dog tapeworm, hydatid
tapeworm.
Common associated disease and condition
names: Echinococcosis, hyatid cyst, hyatid disease,
hyatidosis.
Morphology
Eggs. The eggs of Echinococcus granulosus
are identical to, and thus indistinguishable from,