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48 Cards in this Set
- Front
- Back
Quick salient/disgusting points about the luminal nematodes: 5 kinds
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Ascaris: largest round worm
Hookworm: Causes Fe deficiency anemia Strongyloides: only worm that can multiply within host; dangerous in immunocompromised folks Pin Worm (Enterobius): causes an itchy butt Whip Worm (Trichuris): causes rectal prolapse; can cause Fe anemia |
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Soil transmitted helminths (geohelminths):
-prevalence of 3 major species? -locations around the globe? |
Ascaris lumbricoides 1.2 billion
Trichuris trichiura 800 million Hookworms 740 million -Mostly in sub-Saharan Africa, the Americas, China and east Asia. |
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3 basic points about nematodes (round worms):
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1. Eukaryotes. C. elegans is most common--lives in soil.
2. Most are non-parasitic 3. Almost 4 billion people harbor at least one species of parasitic nematode. Many have >1. |
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Night soil:
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-Feces-fertilized soil
-completes the nematode parasite cycle |
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Enterobius vermicularis:
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-Pinworm
-most common human helminth in the U.S -we ingest the eggs -no soil, lung or GI invasion phases |
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Enterobius vermicularis
Pinworm |
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Life cycle of Enterobius vermicularis:
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Enterobius vermicularis- pinworms
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-unembryonated and embryonated forms.
-flat on one side, round on the other. |
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Diagnosis of Enterobius vermicularis:
Treatment: 2 |
-scotch tape test
albendazole* mebendazole* single dose + repeat after 2 weeks * inhibits polymerization of microtubules which results in depetion of glycogen stores (has no effect on human tubulin) |
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Prevention and Control of Enterobius vermicularis:
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Trichuris trichiura:
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-Whipworm
-3rd most common human helminth globally -soil phase and local GI invasion but no lung phase -We ingest the eggs |
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-adult F on left
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Life cycle of Trichuris trichiura:
symptoms/pathology?? 5 |
-Rectal prolapse and bleeding
-can cause Fe anemia -abdominal pain, nausea -mucus/blood in stool (dysentery) -chronic infection -can be asymptomatic |
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Rectal prolapse in Trichuris trichiura.
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Diagnosis of Trichuris trichiura:
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-µscopic exam of feces for eggs
-ova and parasite test (O&P) |
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Treatment of Trichuris trichiura:
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albendazole (3 days)*
mebendazole (3 days)* * inhibits polymerization of microtubules which results in depetion of glycogen stores (has no effect on human tubulin) |
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Ascaris lumbricoides:
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-giant intestinal roundworm
-most common human helminth globally -soil phase, GI invasion & lung phase *can present like pneumonia |
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Life cycle of ascaris lumbricoides:
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How does infection present in ascaris lumbricoides?
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*loeffler's is the lung syndrome
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-child with heavy ascaris lumbricoides infection
-PEM, or full of worms |
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Common sites of migration in ascaris lumbricoides: 5
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-eggs with larvae of ascaris lumbricoides.
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Treatment of Ascaris lubricoides:
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albendazole (1 dose)* -best method
mebendazole (3 days)* * inhibits polymerization of microtubules which results in depetion of glycogen stores (has no effect on human tubulin) |
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Most common types of hookworms: 2
prevalence: Phases: 3 |
1) Necator americanus
2) Ancylostoma duodenale -2nd most common human helminth globally -soil phase, GI invasion & lung phase |
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Significance of the pit privy?
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-prevents fecal/oral spread because hookworms can crawl only so high out of a pit.
-instrumental in stopping spread of them. |
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adult Ancylostoma duodenale
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adult Necator americanus
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Life cycle of hookworms:
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adult hookworm seen on endoscopy.
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Clinical disease presentations from hookworms:
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1) Fe-deficiency anemia
2) FTS syndrome |
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Diagnosing hookworms:
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-thin shell
-eggs are in feces |
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Treatment of hookworms:
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albendazole (1 dose)*
mebendazole (3 days)* pyrantel pamoate (3 days) * inhibits polymerization of microtubules which results in depetion of glycogen stores (has no effect on human tubulin) |
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Strongyloides stercoralis: phases
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-soil phase, GI invasion, lung phase and free-living cycle
-Larvae in soil penetrate skin |
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-free living female Strongyloides stercoralis
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Who in the U.S. might have Strongyloides stercoralis?
worldwide? |
-Southeastern US and the Appalachia region (esp. eastern Tennessee, Kentucky, & West Virginia) & Puerto Rico
-immigrants, refugees, and military veterans |
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Life cycle of Strongyloides stercoralis:
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*Larvae pass out from stool*
*free living types* *can autoinfect you-->shock, death* |
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Clinical manifestations of Strongyloides stercoralis:
run the gamut |
-asymptomatic
-skin rash/urticaria at entry site (“ground itch”) -pulmonary symptoms (Loeffler’s Syndrome”) -abdominal pain, N&V, diarrhea, dysentery -malabsorption & loss of weight -anemia (ingest blood from intestinal walls) *2˚ bacterial sepsis (worms release bacteria/ translocation) **hyperinfection syndrome (HIV/immunocompromised) with eosinophilia** -death |
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Diagnosis of Strongyloides stercoralis: 3
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-No eggs in the stool
-serology is best (but presence of Abs in not always clear) |
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Treatment of Strongyloides stercoralis: 3
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ivermectin (2 days)*
albendazole (7 days) * Binds to glutamate-gated Cl- ion channels in invertebrate muscle and nerve cells causing paralysis and death of the parasite; also acts as an agonist of GABA, disrupting neurosynaptic transmission. |
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Cutaneous larva migrans: 2 kinds
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-Ancylostoma braziliense & Ancylostoma caninum
-hookworms from young dogs and cats -fail to penetrate skin -“creeping eruption”= “ground itch” -warm climates -not dangerous, easily treatable |
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Treatment of Cutaneous larva migrans:
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albendazole (3 days)
ivermectin (1-2 days)* * Binds to glutamate-gated Cl- ion channels in invertebrate muscle and nerve cells causing paralysis and death of the parasite; also acts as an agonist of GABA, disrupting neurosynaptic transmission. |
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Which worms do you EAT?
Which ones get into you feet from the SAND? |
Enterobius, Ascaris, Trichuris
Strongyloides, Ancylostoma, Necator |