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115 Cards in this Set
- Front
- Back
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What classes of worms are in the phylum platyhelminthes?
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turbellaria
trematoda cestoda |
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Are there any freeliving trematodes?
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No, all are parasites
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Are there any freeliving cestodes?
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No, all are parasites
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What are trematodes?
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Flukes
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What are cestodes?
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Flatworms
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What are the two divisions of trematodes?
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Monogenea (ectoparasites of fish/amphibians)
Digenea (endoparasites of vertebrates) |
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What does digenic mean?
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Two reproductive lifecycles: an asexual phase in an intermediate host, and a sexual phase in a vertebrate host (definitive host)
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What are the 3 ways medically important flukes reproduce sexually?
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Self fertilize (hermaphroditic)
Cross fertilize (between 2 hermaphroditic worms) Fertilzation between a male and female worm |
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What is the typical digean trematode lifecycle?
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Adult in human intestine/liver/etc. Sheds eggs.
Free living larva (miracidium) hatches from egg, infects a snail, forms into a mother sporocyst. Mother sporocyst makes rediae (daughter sporocysts) which migrate thru snail and produce cercariae. Cercariae (multiple) escape snail into water, encyst on vegitation or intermediate host. Metacercaria enter human host by ingesting contaminated vegetation/fish/crustaceans. |
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What is a miracidium?
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Free living larvae that hatches from a trematode egg.
This stage infects snail. |
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What is a mother sporocyst?
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Inside the snail, miracidium transforms to this
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What are rediae?
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Daughter sporocysts created from mother sporocyst inside the snail (asexual)
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What is a cercariae?
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Develops from the rediae in a snail...this stage leaves the snail
Free swimming - encysts on vegitation or on second intermediate host |
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What is a metacercariae:
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Develops from the cercariae encysted on vegetation. This form gains try into human with ingestion.
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What is the difference between trematode and shistosomiasis cercaria?
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In shistosomiasis, the cercaria does not encyst and get ingested, but penetrates the skin of human directly
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What does monoecious mean?
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Hermaphroditic
most DIGENETIC trematodes are monoecious |
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What does dioecious mean?
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Separate sexes. Schistosomes are dioescious.
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What is the difference between monogenea and digenea?
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Monogenea means have one reproductive cycle. Digenea means having two reproductive cycles -- a sexual and an asexual cycle.
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What is the difference between monogenea and monoecious?
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Monogenea means having one type of lifecycle ((e.g. sexual). Monoecious means hermaphroditic (or both sexes in one organism)
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What is the difference between digenea and dioecious?
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Digenea means having two lifecyels (sexual and asexual). Dioecious means having separate sexes (e.g. a male and a female worm)
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How many suckers does a fluke have?
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2 Oral sucker and ventral sucker. Both for attachment.
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Does a fluke have a digestive track?
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Yes, but no anus. So it vomits its poop.
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How do flukes ingest nutrients?
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Orally and through tegument
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What does fluke tegument do?
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Absorbs small adn large molecules
Covered by membrane bound microvilli |
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What do trematodes require for their lifecycle?
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A water source
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What is the common intermediate host of the trematode?
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Snail
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How are trematodes normally past to their definitive host?
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Foodborne
Normally consumption of a second intermediate host (fish, crab, water vegetation) |
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How are schistosomes transmitted?
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Not via food ingestion, but by definitive host water contact
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What are the 4 groupings of trematodes?
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Intestinal flukes
Liver flukes Lung flukes Blood flukes |
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What are the intestinal flukes (4)
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Fasciolopsis buski
Echinostoma spp Heterophyes heterophyes Metagonimus yokagawi |
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What are the liver flukes? (6)
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Fasciola hepatica
Fasciola gigantica Clonorchis sinsesis Opisthorcis viverrini Opisthorchis felineus Dicrocoelium dendriticum |
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What are the lung flukes?
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Paragonimus westermani
Other paragonimus |
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What are the blood flukes?
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Schistosomes
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Where are the organs of the cestodes and trematodes found?
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In the parenchyma
THERE IS NO PSEUDOCOELUM |
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What are flame cells?
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Part of the platyhelminthes excretory system.
Precursors to kidney cells Protonephridal |
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What does the vittelaria of the trematode do?
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Makes egg yolk...part of the reproductive system
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Where find the fasciolopsisbuski intestinal flukes - geog
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East asia
India |
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Where in world are Echinostomes
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Middle east, east asia, africa
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Where in the world are the nanophyetus intestinal flukes?
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Siberia, pacific NW of USA, canada
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How big are fasciolopsis buski?
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7 cm
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What is an operculum?
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A cap on an egg that lets the larva out
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What are the 3 asexual stages of the fluke?
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Inside the snail
Sporocyst Rediae Cercarae |
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Lifecycle of Fasciolopsis buski?
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Eggs shed from small intestine (pig or human) into water, miracidium hatches, invades snail, asex reproduction, creates many cercariae, encyst on a PLANT (like water chestnuts), eaten by human/pig.
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What are the definitive hosts for Fasciolopis buski?
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Pigs and humans
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What food transmits Fasciolepsis buski?
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Uncooked water veggies
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What are the clinical sx of Fasciolepsis buski infection?
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Abdominal pain (ulcerations at mucosal attachment site)
Diarrhea Vomiting Weight loss |
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How to diagnose Fasciolepsis buski infection?
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Eggs in stool
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Treatment of Fasciolepsis buski?
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Praziquantel
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What fluke is NOT treated with praziquantel?
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Fasciola hepatica
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What are the intestinal flukes?
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Fasciolepsis buski (veggies)
Echinostomes Heterophyes Metagonimus Nanophyetus |
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What are the liver flukes? (3)
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Fasciola hepatica
Clonorchis sinensis Opisthorchis viverrini |
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Which liver flukes have sheep, cattle and humans as definitive hosts?
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Fasciola hepatica
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Where in the world is Fasciola hepatica?
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Places where sheep/cattle are: Bolivia, peru, ecuador, iran, egypt, portugal, france, usa
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How do you get Fasciola hepatica?
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Eat uncooked water veggies (like fasciolepsis buski)
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What fluke can crawl up the back of your throat?
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Fasciola hepatica -- if ingested adult fluke (called Halzoun)
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What is Halzoun?
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Pharyngitis from an ingested adult Fasciola hepatica sticking to your throat. Nice.
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What is the Western Liver Fluke?
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Fasciola hepatica
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What causes Fascioliasis?
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Fasciola hepatica
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What is unique about Fasciola hepatica lifecycle, for a trematode?
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When the metacercariae enters human, it rips its way from intestine to biliary tree
Traumatic, painful eosinophilia |
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What is Febrile Fasciolitic Eosiniphillic Syndrome?
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From Fasciola hepatica -- when the metacercariae rip through the abdominal cavity looking for the bilary tree.
Fever, tender hepatomegaly, eosinophilia |
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How to diagnose Fasciola hepatica infection?
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Eggs in stool
Serology Sometimes found by ERCP or surgery or imaging |
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What is the treatment for Fasciola hepatica?
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NOT PRAZIQUANTEL
Triclabendazole or bithionol -- Get from CDC Nitazoxanide |
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How do you get oriental liver flukes?
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Ingestion raw fish
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What are the 3 oriental liver flukes?
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Clonorchis sinensis (China, Korea)
Opisthorchis viverrini (Thailand/Laos) Opisthorchis felineus (W siberia, Kazakhstan) |
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What is the intermediate host for the Oriental Liver Flukes?
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Hydrobiid snails
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What's cool about the testes of Opisthorchis liver flukes?
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Shaped like flowers. Cute.
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What's unique about the lifecycle of the Oriental Liver Flukes?
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The intermediate snail host ingests the EGG, not the miracidium.
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How do the Oriental Liver Flukes get to the biliary tree?
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They kindly follow the duodenum and crawl in....
No tearing, therefore minimal eosiniphila |
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Which fluke can cause cancer?
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LIVER CANCER
Opsithorchis viverrini Maybe Clonorchis sinensis |
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Which fluke is listed as a carcinogen?
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Oriental Liver Fluke Opsithorchis viverrini
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What do the Oriental Liver Flukes do to the liver?
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Oriental Cholangiohepatitis (recurrent pyogenic cholangitis)
F/C, abd pain, jaundice, hepatomeg, dilated hepatic ducts, intrahepatic strictures, recurrent cholangitis, liver abscesses, hepatic destruction |
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What causes Fulminating acute supperative cholangitis?
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Clonorchis sinensis and Opisthorchis viverrini
(2 of the oriental liver flukes) Obstruction of CBD by dead parasites Pancreatitis/Cholangitis/Shock Cholagiocarcinoma with Opisthorchis |
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How to diagnose Oriental Liver Flukes?
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Eggs in stool
Ultrasound/imaging Surgery/ERCP |
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How do you get oriental liver flukes?
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Eating raw fish
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What is the theory behind carcinogenesis with opisthorchis infection?
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Inflammatory response from suckers (mechanical and chemical) thicken liver cells
Compounded by fermented fish toxin (Nitrosamines) ?Synergy leading to cancer |
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What are the 3 problems caused by liver flukes clonorchiasis and opisthorchiasis?
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1. Acute infection (fever, abd pain, eosinophilia, hepatomegaly) due to wanderings in and out of biliary tree
2. Chronic infection (recurrent ascending cholangitis and pancreatitis) 3. Cholangiocarcinoma (exacerbated by nitrosamines in fermented fish) |
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How to treat oriental liver flukes?
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Praziquantel
ERCP to remove parasites and stones |
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How to control liver flukes?
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Cook fish and watercress
Deworm cows/sheep |
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What is a common lung fluke?
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Paragonimus westermani (oriental lung fluke)
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What is the definitive host for Paragonimus westermani?
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Human
and others |
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Where do you get paragonimus westermani?
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(Lung fluke)
From raw/undercooked shrimp, crab, crustaceans |
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What is unique about the adult living situation of paragonimus westermani?
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They live in lungs in pairs
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How does paragonimus westermani get to the lungs?
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Swallowed metacecercariae rip through the body from the gut to the lungs
(eosinophilia, chest pain) |
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What do lung flukes look like on CXR?
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Cysts form cavitiations -- look like TB
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Why doe lung flukes mimick TB?
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Form cavitary lung lesions
Cough up blood May cause weight loss |
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Where in teh world do you find lung flukes?
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China and Philippines
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If you eat drunken crab, what might you catch?
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Lung flukes
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Where else besides lungs might you find lung flukes?
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Brain (cerebral paragonimiasis)
Liver |
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What is pleuropulmonaryparagonimiasis?
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Lung flukes causing:
chest pain hemoptysis cough pulmonary infiltrates |
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How to diagnose lung flukes?
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Eggs in sputum or feces
Serology Bx of eggs or fluke in liver/lungs/etc. |
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Treatment of lung flukes?
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Praziquantel
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True of false: lung flukes pair up because they are not hermaphroditic
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False. They are hermaphrodites. Still, pair and mate.
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Are there non-human reserviours for Paragonimus westermani?
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Yes
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Describe the acute vs. chronic phase of paragonimiasis:
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Lung worm infection:
Acute: Invasion and migration: Abdominal pain, fever, cough, urticaria, HSM, eosinophilia Chronic phases: Cough, discolored sputum, hemoptysis, abnl cxr, mimicks tb |
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Treatment for lung flukes?
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Praziquantel
Bithional |
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Prevention of lung flukes?
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Cook shellfish
Animal reservoir makes control difficult |
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Of small, med, large, which flukes have small eggs?
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Clonorchis
Opisthorchis Metagonimus Heterophyes |
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Of small, med, large, which flukes have medium eggs?
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Paragonimus\
Echinostoma |
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Of small, med, large, which flukes have LARGE eggs?
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Fasciola
Fasiolopsis Schistosoma |
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Of the human flukes, which eggs are NOT have operculate?
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Schistosomes
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Treatment of Fasciolopsis buski?
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Praziquantel 75mg/kg/d divided TID x 1d
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Where does tha adult fasciola hepatica live>?
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Large billiary passages and gallbladder
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Which fluke might you find in the gallbladder?
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Fasciola hepatica
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What is the prepatent period for fasciola hepatica?
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3-5 months
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Where do fasciola gigantica live?
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Africa/Asia
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What are the normal hosts of fasciola gigantica?
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herbivores -- camels, cattle, water buffalos
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Where in the world is Clonorchis sinensis? (oriental liver fluke)
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Japan, China, Taiwan, Korea, Vietnam (25 million infected)!
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If you pickle fish, do you kill metacercariae of liver flukes?
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NOPE
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What are common reservior hosts for clonorchis sinensis?
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Dogs and cats
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What is the most common manifestation of clonorchis sinensis?
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Nothing -- asymptomatic.
Rarely, dyspepsia, abdominal pain, diarrhea, constipation, HSM, malnutriti9on, relapsing cholangitis, gallstones, obstructive jaundice. Rarely cholangiocarcinoma |
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Where in the world is Opisthorchis viverrini?
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Thailand, laos, cambodia
(10 million infected) (up to 70% of thai infected!) |
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How long do Opisthorcis viverrini live?
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Years
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Where in the world is Opisthorcis felineus?
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Germany, poland, russia
Philipines, japan, vietnam |
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What are the definitive hosts of Opisthorchis felineus?
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Cats, dogs, humans, fish-eating mammals
(16 million people infected) |
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Definitive hosts of lung flukes?
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Carnivores: humans, felines, canines, pigs (fresh water crab/crayfish eaters)
20 million humans infected |
