Test 4: Cestodes (Tapeworms) Flashcards
(123 cards)
1
Q
What Cestode has unembryonated, operuclated eggs?
A
Diphyllobothrium latum
2
Q
what areas are Taenia Solium to be more prevalent?
A
- Poorer communities
- Close contact w/pigs
- Eat undercooked Pork
3
Q
Describe the Scolex of Taenia Saginata?
A
- Four, Muscular cup-shaped suckers
- No Crown of hooklets on rostellum
4
Q
Used to determine species, How many uterine branches are found in Taenia Solium and Taenia Saginata?
A
Taenia Solium: 7-13
Taenia Saginata: 12-30
5
Q
What is the length vs width relationship for a Taenia Proglottids? (Generalize, no numbers)
A
Longer than they are wide
6
Q
What may be useful in detecting early invasive stages when the eggs & proglottids are not yet apparent in the stool?
A
Antibody Detection
7
Q
What is the pointed end of the scolex that has point of attachments (suckers, hooklets, etc…) called? Cestodes Characteristic
A
Rostellum
8
Q
Cestodes have what type of reproduction system?
A
Hermaphroditic (Monoecious)
9
Q
How do Cestodes obtain their nutrition?
A
Through Body Walls
-Lack Digestive System
10
Q
What are the segments that form the body of Cestodes (AKA Tapeworms) called?
A
Proglottids
11
Q
A chain of proglottids is called?
A
Strobila
12
Q
What is the portion of a Cestodes in which differ in number and placement of suckers and presence or absence of hooklets?
A
Scolex (head)
13
Q
Describe the Life Cycle of the cestodes, Taenia Saginata and Taenia Solium?
A
1) Eggs or gravid proglottids passed to environment
2) Cattle- T. Saginata
Pigs- T. Solium, ingest contaminated vegetation
3) Oncosphers hatch, penetrate intestinal wall, circulate to musculature
4)Oncosphere develops in cysticerci in pig/cow muscle
5) Humans- ingest undercooked infected meat
6) T. Saginata or T. Solium, scolex attaches to intestine
7) adults in small intestine pass gravida proglottids in stool to environment
14
Q
How many eggs are contained in the gravid proglottids of T. Saginata and T. Solium?
A
T. Saginata: 100,000 per
T. Solium: 50,000 per
15
Q
What is the geographic Distribution of Taenia asiatica?
A
Asia (Mostly Republic of Korea, China, Taiwan, Indonesia, Thailand)
16
Q
What causes Cysticercosis?
A
Infection with larval stages of T. Solium
17
Q
How are humans infected with T. solium that will cause Cysticercosis?
A
1) Autoinfection: ingest eggs either by fecal contamination or proglottids carried into stomach by reverse peristalsis
2) Ingest food contaminated with feces that contains eggs
18
Q
The Eggs of Taenia spp. are indistinguishable from what?
A
Cestodes of genus Echinococcus (tapeworms of dogs/other canid hosts)
19
Q
How can species determination be accomplished for Cestodes?
A
Microscopic identification of Gravid proglottids or scolex
20
Q
The microscopic identification of eggs and proglottids in feces is diagnostic for taenisasis, but this is not possible until when?
A
Development of adult tapeworms (first 3 months following infection)
21
Q
Describe the Scolex of Taenia Solium?
A
Crown of hooklets
Four, muscular cup-shaped suckers
22
Q
Give the Characteristics of Helminths.
A
- Multicellular organisms
- elongated and bilaterally symmetric
- Larger > protozoa
- Tegument: protective covering or cuticle
- Attachment: hooks, suckers, teeth, or plates
- Primitive nervous and excretory systems
- Alimentary canal (some)
- No circulatory system
23
Q
Most Cestode eggs characteristics are what?
A
Nonoperculated and contain hexacanth embryo
24
Q
What is the six-hooked larval form released when the Cestodes eggs hatch called?
A
Oncosphere
25
What is the clinical presentation of Taenia Saginata taeniasis?
- Mild abd symptoms
- Passage (active/passive) of proglottids
- Appendicitis or cholangitis (occasionally)
26
What is the clinical presentation of Taenia solium taeniasis?
- Less frequently symptomatic than T. Saginata taeniasis
- Passage (passive) of proglottids (main)
- Risk of development of Cysticercosis (MOST IMPORTANT FEATURE)
27
What is the drug of choice for treatment of active taeniasis and what drug is an alternative treatment?
Praziquantel
| Alt.: Niclosamide
28
When must Praziquantel be used with caution and why?
Pt w/ Cysticercosis.
| -Praziquantel is cysticidal and may cause inflammation around dying cysts, may lead to seizures or other symptoms
29
What are the post treatment procedures for Taenia?
- Stool collection for 3 days, species id
| - Stool re-examined for Taenia eggs at 1 and 3 months
30
What is the intermediate hosts of the Taenia solium parasite?
Pigs
31
Describe the Scolex of Diphyllobothrium latum?
- Lance-shaped
- Two Leaf-shaped suckers
- Bothria-lateral grooves, serve as organs of attachment
32
Describe the Scolex of Echinococcus?
- Four Sucking Discs
| - Double Row of hooklets
33
What is the general characteristics of the Strobila of the Echinococcus spp.?
Three Proglottids
- One Immature
- One Mature
- One Gravid
34
What is the larval form in humans, slow-growing, tumor-like, and space occupying structure w/membrane (unilocular) called? Echinococcus Characteristic
Hydatid Cyst
35
What are the structures on the wall of the membrane of the hydatid cyst called? Echinococcus Characteristic
Brood Capsules
36
What is a protoscolices? Echinococcus Characteristic
Tapeworm heads that develop in brood capsules
37
Describe the Scolex of Hymenolepis nana?
- Four Muscular suckers
| - Crown of hooklets
38
Echinococcus characteristic in which this forms within the original mother cysts?
Daughter Cyst
39
What is formed when the daughter cysts and brood capsules disintegrate and liberate the protoscolices? Echinococcus Characteristic
Hydatid sand
40
Describe the Scolex of Hymenolepis diminuta?
- Four Muscular suckers
| - No hooklets
41
Symptoms of Cysticercosis are caused by what?
Development of Cysticerci in various sites
42
What is of the greatest concern in the formation of Cysticercosis?
Neurocysticercosis (Cerebral Cysticercosis)
43
What symptoms/manifestations may occurs from formation of Neurocysticercosis?
- Seizures
- Mental Disturbances
- Focal neurologic deficits
- Sign of space-occupying intracerebral lesions
- Sudden Death
44
What may cause ocular, cardiac, or spinal lesions w/ associated symptoms?
Extra cerebral Cysticercosis
45
Laboratory Diagnosis: Demonstration of T. Solium eggs and proglottids in the feces, what is the diagnosis?
Taeniasis
| Not Cysticercosis
46
Laboratory Diagnosis: How is definitive diagnosis of Cysticercosis made?
Demonstration of Cysticercus in tissue
47
In a person found to have eggs or proglottids in their feces what laboratory evaluation should occur?
Serologically tests (concern for autoinfection, resulting in Cysticercosis)
48
Diagnosis of Cysticercosis by demonstration of cysticerci in the tissue is accomplished how?
- X-rays: Appearance of calcified cysticerci in soft-tissue
- CT: CNS lesions detected
- Surgical removal of subcutaneous nodules
- Cysts in the eye
49
This is the immunodiagnostic test of choice for confirming clinical and radiologic presumptive diagnosis of Neurocysticercosis?
CDC's immunoblot assay w/purified T. Solium antigens (Cysticercosis immunoblot) (Ab detection)
50
What type of specimen sample is required for the CDC's immunoblot test for T. Solium?
Serum or CSF
51
What is the treatment of choice for Cysticercosis?
Praziquantel
or
Albendazole
52
What is the largest human tapeworm and is also known as "fish" or "Broad tapeworm"?
Diphyllobothrium latum
53
What are the two intermediate hosts of Diphyllobothrium spp.?
Crustacean and freshwater fish
54
What is the ciliated, free-swimming larval form of Diphyllobothrium called?
Coracidium
55
Copepods (Cyclops and diaptomus spp.) ingest Coracidia form of Diphyllobothrium and it develops into what?
Procercoid larvae in the body cavity of copepods
56
How is the procercoid released from the crustaceans and what do they develop into?
- Ingested by small freshwater fish
| - Develop into: Plerocercoid larva (sparganum) ribbon-like larval worm in flesh
57
Describe the life cycle of Diphyllobothrium.
1) Unembryonated egg passed in feces
2) Eggs embryonate in water
3) Coracidia hatch, ingested by crustaceans
4) Procercoid larvae in crustaceans
5) Crustacean ingested by freshwater fish, procercoid develops into plerocercoid larva
6) Predator fish eats infected small fish
7) Humans ingest raw/undercooked infect fish
8) Adult in small intestine
9) Proglottids release immature eggs
58
What is the typical geographic distribution of Diphyllobothriasis?
- Northern Hemisphere (Europe, N. America, Asia)
- S. America (Uganda and Chile)
- Can occur other locations if infected fish transported to that area
59
Diphyllobothriasis may have what clinical presentations?
- Long-lasting (decades)
- Most asymptomatic
- May include: abd discomfort, diarrhea, vomiting, wt. loss
- Vit. B12 deficiency w/pernicious anemia
- Massive infection: intestinal obstruction
- Migration of proglottids: cholecystitis or cholangitis
60
Laboratory Diagnosis of Diphyllobothriasis can be made by?
Microscopic id of eggs in stool
- Eggs numerous and demonstrated w/out concentration tehniques
- Operculated
- Knob on shell bottom
61
Describe the length vs width of Diphyllobothrium latum proglottids?
Wider than they are long
62
What Cestode demonstrated a central uterine structure resembling a "rosette"?
Diphyllobothrium latum
63
What is the definitive host of the Echinococcus?
Dog and other canidae
64
The adult form of Echinococcus is found where?
Small intestine of definitive host (dogs and other canidae)
65
What is the infective stage of the Echinococcus life cycle?
Embryonated eggs in feces ingested by intermediate host (Humans, sheep, goats, etc...)
66
What is the diagnostic stage of Echinococcus life cycle?
Formation of hydatid cyst in liver, lungs, etc... in the intermediate host
67
How do Dogs get infected with Echinococcus?
Ingestion of cysts from infected organs of intermediate host
68
Echinococcus granulosus occurs worldwide but is more frequently seen where?
- Rural, grazing areas
| - Dogs ingest organs from infected animals
69
Echinococcus multilocularis occurs where?
N. Hemisphere (Central and N. Europe, Asia, N. America)
70
Echinococcus vogeli and Echinococcus Oligarthrus occur where?
Central and S. America
71
What infection remain silent for years (5-20) before enlarging cyst causes symptoms in affected organs?
Echinococcus granulosus
72
What is the clinical presentation of Echinococcus granulosus cysts involvement in the Hepatic and Pulmonary areas?
Hepatic: Abd pain, mass biliary duct obstruction
Pulmonary: Chest pain, cough, hemoptysis
73
What clinical presentation may be seen if the Echinococcus granulosus cysts rupture?
- Fever
- Urticaria
- Eosinophilia
- Anaphylactic Shock
- Cyst Dissemination
74
Echinococcus granulosus may have cysts involving what other areas?
Brain, Bone, Heart
75
What Cestode affects the liver as a slow growing, destructive tumor, w/ abd pain, biliary obstruction, occasionally metastatic lesions into the lungs and brain?
Echinococcus Multilocularis
76
Echinococcus vogeli affects what area?
- Mainly Liver, as a slow growing tumor
| - Secondary cystic development is common
77
What diagnostic technique may provide the first evidence of cyst's presence in echinococcosis?
X-ray
CT
Ultrasound
78
This diagnostic technique is contraindicated in the diagnosis of Echinococcosis due to the risk of allergic anaphylaxis and spread of infection?
Aspiration of cyst contents (demonstrate presence of protoscolices [hydatid sand])
79
Serologic testing in diagnosis of echinococcosis has what rate of negative results?
10% - 40%
80
What is the treatment of choice in Cystic Echioncoccal disease?
Surgical resection of cyst
81
If Cystic echinococcal disease cyst is inoperable due to cyst location what drugs may be prescribed?
High-Dose
- Albendoazole
- Mebendazole
- Praziquantel
82
What is the key to controlling Echinococcosis infections?
- Hand washing
- Utensil Washing
- Personal Hygiene
- No dogs near slaughter houses
- Kill stray dogs
83
This type worm is also known as "Dwarf tapeworm"?
Hymenolepis nana
84
What are the characteristics of the H. nana eggs?
Six-hooked embryo
| polar filaments
85
What is the infective stage of Hymenolepis nana?
- Embryonated eggs in feces
- Ingested embruonated eggs by humans from contaminated food, water, or hands
- Eggs release hexacanth embryo, prenetrates intestinal villus continues cycle
86
What is an extremely rare cause of human echinococcosis?
Echinococcus Oligarthrus
87
Echinococcus Vogeli causes what?
Polycycstic Echinococcosis
88
Echinococcus Multilocularis causes what?
Alveolar Echinococcosis
89
What causes the most frequently encountered form and what is that form?
Echinococcus granulosus causes cystic echionoccosis
90
What is Human echinococcosis (Hydatidosis or hydatid disease) caused by?
Larval stages of cestodes of genus Echinococcus
91
What two cestodes have an autoinfection characteristic in their life cycle?
Hymenolepis nana
| T. Solium
92
What are the Characteristics of the Hymenolepis diminuta eggs?
- Bile stained
- No polar filaments
- Larger than H. nana
93
What Cestode requires larval insects "mealworms" to reach infective cysticercoid stage and has proglottids that overlap each other?
Hymenolepis diminuta
94
The diagnostic stage of the H. diminuta life cycle is what?
Eggs passed in feces
95
The infective stage of the H. diminuta life cycle is what?
-Human or rodent Ingestion of insect infected with cysticerci in body cavity
96
What is the most common cause of all Cestode infections and is encountered worldwide?
Hymenolepis nana
97
H. nana and H. diminuta infections most often have what symptoms?
Asymptomatic
98
A heavy infection w/ H. nana may cause what symptoms?
```
Weakness
Headaches
anorexia
abd pain
diarrhea
```
99
Diagnosis of H. diminuta and H. nana depend on what?
- Demonstration of eggs in stool specimen
- H. Diminuta: Thick outer memberen, hooks
- H. Nana: Thin outer memberen, hooks, polar filaments
100
What is the drug of choice and alt in the treatment of H. nana?
Praziquantel (primary)
| Niclosamide (alternate)
101
Prevention of H. nana is accomplished through what means?
Improve sanitation
| proper personal hygiene
102
What is the drug of choice and alt in the treatment of H. diminuta?
Niclosamide (primary)
| Praziquantel (alternate)
103
Prevention fo H. diminuta is accomplished through what means?
- Rodent control where grain products are produced or stored
| - Inspection of uncooked grain products to detect mealworms
104
What Cestode is known as "pumpkin seed" tapeworm due to shape of mature proglottids and has 25 eggs in a packet?
Dipylidium caninum
105
What is the infective stage of the life cycle of Diphylidium caninum?
Cysticercoid in adult fleas (Flea is a vector)
106
Where have human infections of Diphylidium caninum been reported?
Europe, Philippines, China, Japan, Argentina, U.S.
107
Most infection w/ Dipylidium caninum are what?
Asymptomatic
108
What signs might pets exhibit if they are infected w/ Diphylidium caninum?
scraping anal region on the ground to relieve anal pruritis
109
What is the most striking feature in animals and children infected w/ diphylidium caninum?
Passage of proglottids
110
Where may the proglottids of diphylidium caninum passed by the host be found?
```
perianal region
feces
diapers
Floor
furniture
```
111
What is significant regarding the proglottids of diphylidium caninum that have been passed?
Motile (freshly passed), and may be mistaken for maggots or fly larvae
112
Diagnosis of diphylidium caninum infection can be made by?
Typical proglottids or egg packets in stool or environment
113
What is the treatment for adults infected with diphylidium caninum?
Praziquantel (5-10mg/kg), single dose
114
Praziquantel is not approved for use in what population?
Children under 4
115
What are the names of the cestodes in the genus Spirometra?
- Sparganum mansoni
- S. Ranarum
- S. mansonoides
- S. erinacei
- S. proliferum (aberrant form)
116
Most human cases of sparganosis are recorded from what georgraphic region?
Southeast Asian countries
117
Sparganosis is endemic in what host throughout N. America and human cases are rare?
Animals
118
This infection causes painful inflammatory tissue reaction and nodules, tissue reactions near the eye are very painful, and usually cause periorbital edema?
Sparganosis
119
Corneal ulcers may develop with infections of what?
Sparganosis
120
Ocular disease is often associated w use of what as a poultice over wounds near the eye?
Frog or snake flesh
121
How is diagnosis usually made for sparganum?
Recovery of a sparganum from infected tissue. Id to species level usually not warranted
122
What is the treatment of choice for sparganosis infection?
Surgical removal
123
Treatment with what is generally not effective to treat infection w/ these larvae of sparganosis?
Mebendazole
Albendazole
praziquantel
