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24 Cards in this Set
- Front
- Back
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Which of the three groups of helminths are not always parasitic? |
Nematodes (Round Worms)
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What is the hygiene hypothesis as it relates to helminths?
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Early exposure to helminths is required for proper tuning of the immune system to avoid damaging T-helper-1 responses seen in autoimmune disorders.
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How many legs does a nematode have?
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None
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Describe the life cycle of trichuris trichuria.
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1) Ingested by a human as an egg. This is the infective stage. 2) Larvae hatch in small intestine. 3) Molt 4 times. 4) Migrate to the large intestine and set up shop.
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Are there both male and female whipworms?
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Yup
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What is the transmission route of trichuris trichuria?
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Fecal-oral route
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What do the eggs of trichuris trichuria look like? Why is this important to know?
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Barrel shaped with bipolar plugs. EGGS ARE DIAGNOSTIC!
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Do whipworms multiply in the host?
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Nope. So...worm burden depends on number of eggs ingested.
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What 2 diseases does trichuris show promise in treating?
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Crohn's disease and autism
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Whipworms (trichuris) are found world-wide (you knew that of course). What climate locations are whipworms more commonly found in?
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Tropical areas
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What is the treatment of choice for whipworms?
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Mebendazole. This drug inhibits tubulin polymerization, and results in immobilization of the worm.
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How many hosts does ascaris lumbricoides inhabit?
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Just one.
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What is the tranmission route of ascaris lumbricoides?
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Fecal-oral route.
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What is the infective stage of ascaris lumbricoides?
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2nd stage larvae (by ingestion).
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What problems does ascaris lumbricoides cause in the lungs?
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Cough, pneumonia, Loeffler's syndrome (eosinophilic pneumonia), Allergy
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If you find a lot of roundworm eggs in the feces, does it mean there are a lot of roundworms in the intestine?
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Nope.
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What is the problem with using serology to diagnose ascaris lumbricoides infection?
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It is not specific. Cross-reacts with antigens from other helminths.
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What does a roundworm infection look like on a radiograph?
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This produces a "whirlpool image."
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What is the treatment of choice for ascariasis?
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Albendazole or mebendazole for most patients. Pyrantel pamoate if pregnant. Piperazine if intestinal obstruction. Corticosteroids may be used for pulmonary symptoms.
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How do you prevent/control ascariasis?
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Don't use human feces as fertilizer. Can do mass treatment of albendazole or mebendazole.
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How does a human get infected by anisakis simplex or pseudoterranova decipiens?
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By eating raw/undercooked marine fish.
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Which stage of the life cycle of anisakis simplex is the infectious stage?
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3rd stage larvae
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What are the natural hosts of anisakis simplex and pseudoterranova decipiens?
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Marine mammals definitive host. Crustaceans and fish/squid are intermediate hosts.
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How do you treat anisakis simplex?
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Remove the larvae (surgically/endoscopically).
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