Dr. Libman -- Parasitology 4: Trematodes and Cestodes Flashcards

1
Q

What are trematodes commonly known as?

A

Flukes

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2
Q

Phylum under which cestodes and trematodes belong

A

Platyhelminthes

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3
Q

4 types of trematodes

A
  1. Schistosoma
  2. Opisthorchis
  3. Paragonimus
  4. Fasciola
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4
Q

Location of adult schistosoma

A

Human blood

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5
Q

Location of adult opisthorchis

A

Human liver

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6
Q

Location of adult paragonimus

A

Human lung

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7
Q

Location of adult fasciola

A

Human liver

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8
Q

Source of schistosoma

A

Water

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9
Q

Source of opisthorchis

A

Freshwater fish

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10
Q

2 sources of paragonimus

A

Freshwater crabs and cray fish

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11
Q

Source of fasciola

A

Watercress

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12
Q

Types of flukes that are hermaphroditic

A

Liver flukes, lung flukes, etc

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13
Q

Type of flukes that have two sexes

A

Blood flukes

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14
Q

Describe the general trematode life cycle (5 steps)

A
  1. Adult lives in human
  2. Lays egg
  3. Miracidium released
  4. Snail harbors redia/sporocysts
  5. Cercaria released and enters human through tissue (~2 days) OR metacercaria released into/onto fish, crabs and watercress
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15
Q

Describe the mating process of schistoma

A

Female lives inside the male and they mate for life while hugging

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16
Q

Location of schistosomule maturation

A

Portal veins near liver

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17
Q

Location of schistosoma eggs in human

A

Small venules of pelvic or mesenteric venous plexuses

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18
Q

Describe the fate of schistosoma eggs

A

Pass through tissue to lumen of bladder or colon (depends on location) and are voided

OR

Pass into venules and end up in liver

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19
Q

4 organisms of intestinal schistosomiasis

A
  1. S. mansoni
  2. S. japonicum
  3. S. intercalatum
  4. S. mekongi
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20
Q

Urinary schistosomiasis

A

S. hematobium

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21
Q

Distribution of S. hematobium (3)

A
  1. Sub-saharan africa
  2. Some middle east
  3. Madagascar
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22
Q

Geographic distribution of S. japonicum (2)

A
  1. Eastern China
  2. Southerm Japan
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23
Q

Geographic distribution of S. mansoni (4)

A
  1. Sub-saharan Africa
  2. Some middle east
  3. East coast of brazil
  4. Some Caribbean
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24
Q

Consequence of schistosomas eggs landing in liver as opposed to leaving the body

A

Portal fibrosis –> portal hypertension

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25
4 types of clinical manifestations of intestinal schistosomiasis
1. Portal hypertension 2. Pulmonary hypertension 3. CNS lesions 4. Intestinal polyposis
26
4 manifestations of portal hypertension in intestinal schistosomiasis
1. Splenomegaly 2. Esophageal varices 3. Hypersplenism 4. Ascites
27
2 CNS lesions associated with intestinal schistosomiasis
1. Spine = transverse myelitis 2. Cerebral = seizures (*S. japonicum*)
28
3 manifestations of intestinal polyposis in intestinal schistosomiasis
1. Both sessile and pedunculated contractures 2. Intusseception 3. Chronic salmonellosis
29
5 ways to diagnose intestinal schistosomiasis
1. Stool ova 2. Serology 3. Large intestine 4. Liver biopsy 5. Ultrasound
30
Presentatino of urinary schistosomiasis (7)
1. **Hematuria (terminal)** 2. Urinry frequency 3. Pyuria 4. Pyelonephritis 5. Obstructive uropathy 6. **Cancer of bladder (squamous cell)** 7. Distant metastases (spinal column; pulmonary HTN)
31
5 ways to diagnose urinary schistosomiasis
1. Debris in urine 2. **Eggs in urine (overnight-millipore)** 3. IVP abnormalities 4. Cystoscopy 5. Serology
32
Only treatment for schistosomiasis
Praziquantel
33
4 liver flukes and their geographic distributions
1. Opisthorchis viverini (Oriental) 2. Clonorchis sinensis (Oriental) 3. Fasciola hepaticum (Worldwide) 4. Metorchis conjunctus (Canada)
34
How do liver flukes get to the liver?
Via intestine to do one of two things: 1. Enter the biliary tree or gallbladder * Clonorchis * Opisthorchis * Metorchis 2. Hard way = break through intestinal wall and lier parenchyme to reach the same destination * Fasciola
35
Geographic distribution of Clonorchis sinensis (4)
1. China 2. Vietname 3. Philippines 4. South Korea
36
Geographic distribution of opisthorchis fileneus (2)
1. Eastern Europe (incl Russia) 2. Kazakhstan
37
Geographic distribution of opisthorchis viverni
Southeast asia
38
Presentation of new liver fluke infection (3)
1. Pain in liver 2. Fever 3. Eosinophilia
39
Presentation of chronic liver fluke infection (3)
1. Ascending cholangitis 2. Multiple liver abscesses 3. Cholangiocarcinoma
40
3 ways to diagnose liver flukes
1. Eggs in stool 2. Adults in biliary drainage 3. CT
41
Define a tapeworm
A flat, hermaphroditic, gutless (i.e. segmental) freight train of a worm
42
Fish tapeworm
*Diphyllobothrium *spp.
43
Geographic distribution of *Diphyllobothrium* spp.
Worldwide (dendriticum in north)
44
What puts you at risk of acquiring *Diphyllobothrium *infection
Raw **freshwater** fish consumption
45
2 presentations of fish tapeworm infection
1. Asymptomatic 2. Intermittant abdominal pains
46
*Diphyllobothrium *Treatment
Praziquantel 600 mg once
47
Deficiency associated with *D. latum *(fish tapeworm)
B12 deficiency (mostly FInland)
48
Beef tapeworm
*Taenia saginata*
49
Pork tapeworm
*Taenia solium*
50
DIfference between *T. solium *(pork) and *T. saginata *(beef)
Similar gross appearance but: * Saginata = lots of uterine branches * Saginata = more motile, so may crawl out of butt
51
Geography of *T. saginata*
Raw beef eating countries (i.e. Ethiopia and Lebanon)
52
Geography of *T. solium*
Areas of pig raising and/or poor sanitation
53
Risk factor for acquiring *Taenia* infection
Raw meat eating
54
3 presentations of *Taenia *infection
1. Asymptomatic 2. Rare intermittent abdominal pains 3. *T. solium *= cysticercosis
55
*Taenia saginata/solium *treatment
Praziquantel
56
At what life cycle stage for *taenia solium *cause cysticercosis
Larval stage
57
Describe the NORMAL lifecycle of *T. solium* (6 steps)
1. Human carries tapeworm 2. Human poops out tapeworm -- segments of worm or eggs or both in poop 3. Pig eats poop 4. Pig develops muscle cyst 5. Human kills pig to make uncooked pork chops 6. Human eats muscle cyst
58
Definitive host of *T. solium*
Human
59
Intermediate host of *T. solium*
Pig
60
Dead end host of *T. solium* and consequence
* Human (and dog, cat, deer, etc; not pig) * Human eats poop but tapeworm thinks you're a pig and tries to make muscle cyst and doesn't know where to go * Worm ends up in brain --\> cystacercal larvae in brain
61
Clinical picture of *T. solium-*induced cysticersosis (3 main with subpoints)
1. Intracerebral space occupying (1.5 cm) lesion * Headache * Seizures * Focal neurological defects 2. CSF flow obstruction --\> hydrocephalus 3. Basalar meningitis * Cranial nerve palsies * Hydrocephalus NOTE: manifestations occur when larvae die and become inflammatory
62
Geographic distribution of cysticercosis due to *T. solium*
Central America and South America
63
Dog tapeworm
*Echinococcus granulosis*
64
Definitive host of *E. granulosis*
Human
65
Describe the sylvatic (Canada) life cycle of *E. granulosis *(5)
1. Hydatid cyst (larval) develops in liver of caribou or moose 2. Wolf kills the caribou/moose and eats its liver 3. Adult tapeworm in wolf 4. Wolf poops out parts of tapeworm 5. Caribou/moose eats grass with wolf poop
66
Describe the pastoral life cycle of *E. granulosis *(4)
1. Infected farm dog poops out tapeworm 2. Sheep eats dog poop in grass --\> develop hydatid cysts in liver 3. Farmer kills sheep 4. Farmer gives leftover bits (i.e. liver) for dog to eat 5. Dog gets adult tapeworm
67
Geographic distribution of *E. granulosis* sylvatic (2) and pastoral (3)
* Sylvatic = Canada and Alaska * Pastoral = Southwest USA, parts of Mexico, Southern South America
68
What can form **inside** liver cysts of *E. granulosis*
Daughter cysts
69
Common alternative location for *E. granulosis*
Lung
70
3 complications of dog tapeworm
1. Rupture 2. Superinfection 3. Mass effect
71
5 locations/symptoms of cyst rupture with dog tapeworm
1. Peritoneum 2. Pleura 3. Biliary tree 4. Anaphylaxis 5. Spill into any system --\> metastatic cysts
72
Consequence of superinfection of dog tapeworm cyst
Liver abscess
73
When does dog tapeworm cause pathology in humans?
If humans are an accidental host for the larval stage (i.e. we eat the dog poop)
74
3 mass effects of dog tapeworm cysts
1. Cholestasis 2. Portal HTN 3. Budd-Chiari Syndrome
75
4 treatments for dog tapeworm cysts
1. **Primary = surgery** 2. Percutaneous aspiration, injection of sterilizing agent 3. Chemotherapy (albendazole; only OK) 4. Observation (i.e. if cyst is not too big or if patient is older or has underlying disease --\> cyst may be dead)
76
4 indications for surgery of dog tapeworm cyst
1. Leaking cysts 2. Infected cysts 3. Multiple daughter cysts 4. Biliary tree communication
77
3 indications for PAIR treatment of dog tapeworm cysts
1. Pregnancy 2. Little internal echogenic material 3. Concomitant disease
78
2 indications for chemotherapy of dog tapeworm cysts
1. Inoperable 2. In-aspiratable
79
4 indications for observation of a dog tapeworm cyst
1. Pastoral strain 2. Extreme age 3. Much calcification 4. Well-padded small cysts