Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/69

Click to flip

69 Cards in this Set

  • Front
  • Back
What type of trematodes have separate sexes?
Schistosomes

NOTE: other flukes are hermaphrodites
What is the definitive host for schistosomes?
Human
What is the intermediate host for schistosomes?
Snail
What part of the body do adult schistosomes inhabit?
Portal and mesenteric vessels
Why can schistosome infection in the U.S. not be transmitted?
Lack of appropriate snail species
What is the clinical presentation of schistosomiasis a.k.a?
Bilharzia or Bilharziosis
How do most schistosome infections present?
Most are actually asymptomatic
What are the 3 major syndromes assoc. w/ schistosomes?
Dermatitis ("swimmer's itch")
Katayama fever (ACUTE schistosomiasis)
Chronic schistosomiasis
Where in the U.S. is dermatitis (schistosome) most prevalent?

What type of schistosome does this involve?
Great Lakes region

NOTE: this most commonly involves AVIAN schistosomes
Stage of schistosome life cycle corresponding to Katayama fever
Worms have matured
Beginning of egg deposition
Stage of schistosome life cycle corresponding to Chron. Schisto.
Mature worms
Heavy egg deposition
What part(s) of the body is chronic schistosomiasis most common in?
Liver and intestines
Where in the body are S. haematobium lesions found?
Bladder and uterus
What is Symmers' pipestem fibrosis?
Continuous fibrosis elicited in the liver
(due to granulomatous response to schistosome eggs)

NOTE: eggs can also lodge in the lung and spinal cord
What is the DOC for schistosomes?
Praziquantel
What is the intermediate host for clonorchis sinensis?
Snail
How do humans become infected w/ clonorchis sinensis?
Eating undercooked fish
Where in the body do adult clonorchis sinensis mature?
Bile ducts
Where in the body do clonorchis sinensis excyst?
Duodenum
What is the DOC for clonorchis sinensis?
Praziquantel
What parasitic infection is opisthochiasis most similar to?
Clonorchiasis
What are the natural hosts for Fasciola hepatica?
Sheep and cattle
Where do fasciola hepatica encyst?
Aquatic grasses and plants
How do humans get infected w/ fasciola hepatica?
By eating watercress
Where in the body are adult fasciola hepatica located?
Biliary system
What do early infections w/ fasciola hepatica cause?
RUQ pain
Enlarged liver
Eosinophilia


Later --> bile duct obstruction, biliary cirrhosis
What is the DOC for fasciola hepatica?
Bithionol
What part of the intestine do intestinal flukes inhabit?
Upper portion of the small intestine
What do fasciolopsis buski encyst on?

Where (in the world)?
Aquatic plants

SE Asia, Far east
What do heterophyes heterophyes encyst on?

Where (in the world)?
Brackish fish

NILE DELTA, SE Asia, Far east
What is the DOC for intestinal flukes?
Praziquantel
What two parasites are intestinal flukes?
Fasciolopsis buski
Heterophyes heterophyes
What are common Sx of intestinal fluke infection?
Diarrhea
Ab pain
Signs of malabsorption in stools
Where in the body are adult paragon. westermani found?
Lung parenchyma (close to bronchioles)
Where are egges of paragon. westermani found?
Coughed up in the sputum of infected people
What is the intermediate host for paragon. westermani?
Snail
What do paragon. westermani encyst on?
Crayfish and crabs
How do humans get infected w/ paragon. westermani?
Eating undercooked crustaceans
What is the DOC for paragon. westermani?
Praziquental
What is the scolex?

The strobila?
The head of a tapeworm

The tail of a tapeworm
How do tapeworms attach to our small intestines?
W/ suckers or hooks on their scolices
What is the range of sizes tapeworms can come in?
Few millimeters to 25 meters
What is the definitive host for cestodes (tapeworms)?
Human
What is the intermediate host for diphyllobothrium latum?
Copepods, then fish
What is the intermediate host for echinococcus granulosus?
Sheep, cattles, humans
What is the intermediate host for Echinococcus multilocularis?
Rodents, humans
How do humans get infected w/ taenia saginata?
Eating undercooked beef w/ cysts
How can taenia saginata infection be diagnosed?
MOTILE proglottids in stool

NOTE: release is sporadic, so stools on several days may be needed
What is the treatment for taenia saginata?
Praziquantel or Niclosamide
How do humans get infected w/ taenia solium?
Eating undercooked pork w/ cysts

OR

Eating undercooked pork w/ eggs inside --> cysticercosis
What is cysticercosis?
Infection w/ taenia solium eggs leading to CYST FORMATION
What is the most common parasitic disease of the CNS?
Neurocysticercosis
How does stool detection of T. solium differ from T. saginata?
T. solium proglottids are NON-motile
What is the treatment for T. solium?
Praziquantel or niclosamide
What are the treatment options for cysticercosis?
Albendazole, Praziquantel, or surgical removal of cysts

NOTE: intraocular cysts should NOT be treated w/ drugs
What are the intermediate hosts of diphyllobothrium latum?
1st -- snail
2nd -- fish
How long can diphyllobothrium latum grown?

How long can they survive?
Up to 25 meters

Up to 30 years
What are some of the Sx of diphyllobothrium latum infection?
Ab discomfort, Salt craving, Diarrhea
Megaloblastic anemia (B12 def.)
What are the treatment options for diphyllobothrium latum?
Praziquantel or nuclosamide
B12 if necessary
How is hymenolepsis nana spread?
Human to human

Fecal-oral, or autoinfection
Life cycle of hymenolepsis nana
Eggs hatch to oncospheres
Encyst as cysticercoid larvae
Cyst ruptures to form adult worm


ALL of this happens in the human intestine
How big can adult hymenolepsis nana get?
15 - 50 millimeters
What are the treatment options for hymenolepsis nana?
Praziquantel or niclosamide

NOTE: cystercoid cysts may require a 2nd treatment
(not as susceptible to drugs)
What type of cyst does. E. granulosus cause?

Where in the body are the most common sites?
Hydatid cysts

Liver and lungs
What type of cyst does E. multilocularis cause?

Where in the body is the most common site?
Alveolar cysts

Liver
What is the definitive host of Echinococcus?
Dogs

Humans are inadvertent hosts
(ingest eggs by contamination w/ feces of infected dogs)
What are the treatment options for E. granulosus?
Surgical resection
Albendazole or mebendazole
How do E. multilocularis cysts reproduce?
Asexually
How is E. multilocularis infection treated?
Surgical removal and adjunct Albendazole therapy