Cestodes Flashcards
The cestode morphologic form characterized by a segmented appearance that houses male and female reproductive structures is referred to as a(an): (Objective 10-1)
A. Scolex
B. Proglottid
C. Egg
D. Cyst
B. Proglottid
Characteristics of the cestodes include all the following except: (Objective 10-9)
A. They are hermaphroditic.
B. They generally require intermediate host(s).
C. Their laboratory diagnosis consists of finding larvae in feces.
D. Their anatomic regions include the scolex, neck, and strobila
C. Their laboratory diagnosis consists of finding
larvae in feces.
A persistent cough, localized pain, and liver and lung involvement are associated with an infection with which of the following cestodes? (Objective 10 6)
A. Diphyllobothrium latum
B. Echinococcus granulosus
C. Both A and B
D. Neither A nor B
B. Echinococcus granulosus
Which of the following are key distinguishing factors in differentiating an infection between T. saginata and T. solium? (Objective 10-9)
A. Egg morphology and number of uterine branches in proglottid
B. Presence of hooklets on scolex and egg morphology
C. Presence of hooklets and number of uterine branches in proglottid
D. Egg morphology and presence of suckers on scolex
C. Presence of hooklets and number of uterine branches in proglottid
The primary means of developing an intestinal infection with Taenia spp. is via which of the following? (Objective 10-5)
A. Skin penetration of larvae
B. Ingestion of raw or poorly cooked meat
C. Egg consumption
D. Drinking contaminated water
B. Ingestion of raw or poorly cooked meat
Which is the preferred drug for treating intestinal infection by Taenia spp.? (Objective 10-7)
A. Praziquantel
B. Penicillin
C. Nicolasamide
D. Pentamidine
A. Praziquantel
Which of the following is characteristic of an H. diminuta egg? (Objective 10-10A)
A. Spherical, with radial striations
B. Ellipsoid, with terminal polar plugs
C. Oval, with thin shell and polar filaments
D. Oval, with polar thickenings and no filaments
D. Oval, with polar thickenings and no filaments
The infective stage of H. diminuta for humans is which of the following? (Objective 10-5)
A. Rhabditiform larva
B. Cysticeroid larva
C. Embryonated egg
D. Encysted form
B. Cysticeroid larva
Prevention and control measures against H. diminuta include all except which of the following? (Objective 10-7B)
A. Vaccination program
B. Effective rodent control
C. Inspection of food prior to consumption
D. Protection of food from rodents
A. Vaccination program
A primary differential feature between an H. nana egg and H. diminuta egg is which of the following? (Objective 10-9)
A. A flattened side for H. diminuta egg
B. A thick shell for H. nana egg
C. Polar filaments in H. nana egg
D. Radial striations in H. diminuta egg
C. Polar filaments in H. nana egg
The characteristic of the life cycle of H. nana that differentiates it from the other cestodes is which of the following? (Objective 10-9)
A. Lack of an intermediate host.
B. Infective larval stage.
C. Need for external environment
D. Larval passage through the lungs
A. Lack of an intermediate host.
Which of the following does not apply to H. nana? (Objectives 10-3, 10-6, 10-7A, 10-7B)
A. Dwarf tapeworm
B. Steatorrhea
C. Proper hygiene and sanitation procedures
D. Praziquantel therapy
B. Steatorrhea
A unique characteristic of Dipylidium caninum is which of the following? (Objective 10-10A)
A. Lack of suckers on the scolex
B. Formation of egg packets
C. Proglottid resemblance to Taenia solium
D. Alternation of female and male proglottids
B. Formation of egg packets
A 2-year-old girl and her pet dog were diagnosed with D. caninum infection. This infection was acquired by which of the following? (Objective 10-5)
A. Ingestion of the parasite’s egg
B. Penetration of soil larva
C. Ingestion of a flea
D. Consumption of poorly cooked beef
C. Ingestion of a flea
Prevention and control measures to prevent D. caninum infection include all except which of the following? (Objective 10-7B)
A. Treat dog and cat pets to prevent fleas.
B. Warn children against dog and cat licks.
C. Deworm dog and cat pets, as needed.
D. Neuter dog and cat pets.
D. Neuter dog and cat pets.
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
A. An operculum and terminal knob
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
B. Copepod-procercoid
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 B12 deficiency
D. Fat malabsorption
C. Vitamin B12 deficiency
Which of the following procedures would not be appropriate for diagnosing an infection with Echinococcus granulosus? (Objective 10-8)
A. Serologic procedure, such as ELISA
B. O&P examination of stool specimen
C. CT scan of suspect organ
D. Biopsy of cyst
B. O&P examination of stool specimen
In humans, Echinococcus granulosus infection results in which of the following? (Objective 10-5)
A. Eggs similar to those of H. nana
B. A nutritional deficiency
C. A hydatid cyst
D. Filariform larva
C. A hydatid cyst
Which of the following is not a usual site for Echinococcus granulosus infection in humans? (Objective 10-8)
A. Brain
B. Liver
C. Lung
D. Genitalia
D. Genitalia
Contains both male and female organs
Hermaphroditic
Head of a tapeworm
Scolex
Acquired from animals
Zoonotic
Hexacanth embryo
Oncosphere
Larval form of Taenia spp.
Cysticerus
Smaller cyst within a hydatid cyst
Brood capsule
Series of proglottids
Strobila
Segment of a tapeworm
Proglottid
Free-swimming larva of D. latum
Coracidium
Develops from a procercoid larva
Sparaganosis
Taenia saginata
Beef tapeworm
Dipylidium caninum
Dog and cat tapeworm; pumpkin seed tapeworm
Hymenolepis nana
Dwarf tapeworm
Diphyllobothrium latum
Fish tapeworm
Taenia solium
Pork tapeworm
Echinococcus granulosus
Hydatid tapeworm; dog tapeworm, less commonly
Hymenolepis diminuta
Rat tapeworm
In what parts of the world is Diphyllobothrium latum endemic?
Great Lakes region; parts of South America, Asia; Central Africa; Baltic region; Finland
What is the pathology most commonly associated with Diphyllobothrium latum ?
Vitamin B12 deficiency
What is the pathology most commonly
associated with Echinococcus granulosus?
Cyst development in various organs
Infective stage of Taenia saginata
Cysticercus
Infective stage of Dipylidium caninum
Cysticercoid larva (in flea)
Infective stage of Hymenolepis nana
Egg
Infective stage of Diphyllobothrium latum
Plerocercoid
Infective stage of Taenia solium
Cysticercus
Infective stage of Echinococcus granulosus
Egg
Infective stage of Hymenolepis diminuta
Cysticercoid larva (in beetle or flea)
What is the specimen of choice for the laboratory diagnosis of the following:
Taenia saginata
Dipylidium caninum
Hymenolepis nana
Diphyllobothrium latum
Taenia solium
Hymenolepis diminuta
Stool
What is the specimen of choice for the laboratory diagnosis of Echinococcus granulosus?
Serum specimen for serology or biopsy
Four suckers and no hooks
Taenia saginata
Four suckers and rows of tiny hooklike spines
Dipylidium caninum
Four suckers and short rostellum with one row of hooks
Hymenolepis nana
Lateral sucking grooves
Diphyllobothrium latum
Four suckers with two rows of hooks
Taenia solium
Four suckers and up to 36 hooks
Echinococcus granulosus
Four suckers and rostellum with no hooks
Hymenolepis diminuta
Differentiate the proglottids of Taenia sagninata and Taenia solium.
Taenia saginata proglottids have 15 to 30 lateral uterine branches, whereas Taenia solium has less than 15 lateral uterine branches.
A 30-year-old recent immigrant from Mexico, living in Colorado, presented to the Hispanic Health Clinic after experiencing a seizure at his worksite His history revealed numerous headaches for several weeks. The basic neurologic examination was normal; however, fearing a malignancy, the physician ordered a CT scan. Calcified lesions were noted. A biopsy revealed a parasitic infection. What organism is suspected?
Taenia solium
A 55-year-old man and his family had returned to the United States after a visit to his native Finland. While there, he enjoyed fishing and cooking the fish over an open fire. After his return, he visited his physician with complaints of diarrhea, abdominal pain, and some cramping. Bacterial culture of a stool specimen was negative for enteric pathogens. However, the microscopic O&P examination revealed several large, oval, operculated eggs. With this brief history, which tapeworm is suspected?
Diphyllobothrium latum
