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32 Cards in this Set
- Front
- Back
What are the presenting symptoms?
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1) worsening abdominal pain
2) diarrhea 3) nausea 4) vomiting with blood 5) RUQ pain |
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What is seen on physical exam?
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1) enlarged spleen and liver
2) mild tenderness |
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What does blood work show?
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1) eosinophilia
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it is also known as?
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bilharziasis
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schistosomiasis is caused by what?
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blood trematodes (helminths)
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What are the 3 main species of schostosoma?
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1) haematobium
2) japonicum 3) mansoni |
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Where does S haematobium reside in the body?
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venous plexus near urinary bladder and ureters
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Where does S mansoni reside?
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IMV
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Where does S japonicum live?
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SMV of both small and large intestine
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how large are adult worms?
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12-26mm
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what is the sexual cycle
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adult worms fuck and lay eggs
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what is most practical way to diagnose?
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eggs in stool
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Someone returning from S America, carribean, africa, and middle east would most likely be infected with which species?
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mansoni
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Someone returning from china and southeast asia most likely has which species?
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japonicum
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someone returning from africa and the middle east is most likely infected with?
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mansoni or haematobium
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How does transmission occur?
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penetration of skin from infective cercariae released from infected snails into fresh water
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Describe the life cycle of mansoni?
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eggs shed in human feces, release miracidia which infect snail and undergo 2 generations of sporocysts and produce cercariae. Cercariae are released to water and infect human. They shed forked tail and become schistosomulae which penetrate several tissues. In venous blood adults mate and eggs laid 4-6 weeks after initial penetration (get KF at this point)
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Are adult worms pathogenic?
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rarely
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How long does the adult female persist to lay eggs?
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3-8 years and sheds eggs in feces
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What immune response help eliminate adult mansoni?
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none they can evade all known immunity
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What is occurring in chronic schistosomiasis?
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immunologic reaction to trapped eggs in tissues
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What is the hallmark of schistosoma?
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eosinophillia and hyper IgE release
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what happens when TH2 cells are activated? what results? What happens in the latter stages?
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1) a granulomatous reaction
2) inflammation of liver causing portal hypertension with hematemesis and hepatosplenomegaly 3) collagen deposition and fibrosis result in some irreversible liver damage. Note that the predominate cell type are now B cells |
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What is the treatment of choice?
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praziquantel for all species. it increases membrane permeability to calcium
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Why does allergic dermatitis occur in someone but not others?
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occurs in people with prior exposure
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What is katayama fever?
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it is characterized by fever, cough, abdominal pain, diarrhea, hepatosplenomegaly, and eosinophilia. Serum sickness can result from egg antigen immune complex
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which species causes the most severe form of KF?
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japonicum
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Is KF acute or chronic given that it occurs at 4-6 weeks?
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it is acute and occurs when the eggs are released
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someone presents with the inability to void and is infected with one of the species which is it?
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the eggs of haematobium get trapped in the bladder and cause granuloma formation
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Besides granuloma formation in the ureters and bladder what else is present in haematobium infection?
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hematuria, scarring and calcium build up in bladder wall
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What is a defining feature of the egg on exam?
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oval shape with a prominent lateral spine
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when an egg is in a tissue what surrounds it?
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granulamatous material and cells
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