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41 Cards in this Set
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What helminths cause intestinal distress only? |
Tapeworms : Taenia solium, Taenia saginata, Hympenolepsis Roundworms: Trichuris trichiura (whipworm) & enterobius vermicularis (pinworm) |
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___________ tapeworm contaminated undercooked pig & beef scolex attachment Scolex (head) contains suckers & hooklets proglottid (hermaphroditic reproduction) human = definitive host *Intestinal distress only |
Taenia solium (pig) & Taenia saginata (beef) |
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Describe the pathogenicity of taenia |
contaminated meat contain cysticerci (encysted larvae) (cow or pig = intermediate host)--> humans ingest meat w/ liver cysteicerci--> larvae is released from cyst in intestine--> larvae scolex attach to intestine--> develop into mature worm--> mature worm is segmented, each segment has proglottid (bisexual unit)--> proglottids & eggs are released in stool |
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In ____________ humans can also be the intermediate host (in cases of auto-inocculation --> eggs hatch--> release larvae into circulation)
what does this lead to? |
Tinea solium (pig)
Cysticercosis= cysticerci (encysted larvae) develop in muscles, heart, lung, liver, brain, & eye--> larva death stimulates inflammatory rxn--> fever, muscle pain, subcutaneous nodules, & eosinophilia = meningoencephalitis (rxn in brain) |
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How is tinea dx?
Tx?
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dx: eggs & proglottids in stool (solium species differentiated by having much fewer lateral branches in egg)
cysticercosis--> dx w/ MRI, CT, X-ray--> shows cysticercus & lesion (in brain, heart, etc) + elevated muscle enzymes if in muscle
Tx: praziquantal (or niclosamide, destroys proglottid but not egg, not as good) |
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___________ roundworm fecal-oral transmission infected via egg contaminated linens, counters, clothes, hands, etc (anything & everything) *Intestinal distress only, esp in children |
Enterobius vermicularis (pinworm) |
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Enterobius vermicularis infection cause extreme _____________-----> females lay eggs at night--> eggs hatch w/i 6 hrs--> juveniles crawl back up = retroinfection |
extreme perianal itching & sleep disruption****
(humans ingest eggs--> eggs hatch in small intestine--> female worms mature & migrate to anus--> deposit new eggs on perianal skin--> egg hatch & juveniles crawl back into anus)
*mostly in children bc they don't wash hands, even after butthole itching |
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How is enterobius vermicularis dx?
tx? |
dx: cellophane tape collection & egg (ova) ID--> egg is flat on one side, convex on other & contains larvea (may also ID adult pinworm, fine pointed ends)
tx: pyrantal pamoate or mebendazole* (tx entire family, prevent reinfection) *wash hands a million times to prevent |
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_____________ whipworm (nematode) fecal-oral transmission, assoc w indiscriminate defecation, eggs contaminate soil, step in it warm humid environment very long life-span (up to 8 yrs) *intestinal distress only |
Trichuris trichiura |
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Trichuris trichiura can cause extreme irritation to the large intestine & lead to __________ & ________ |
appendicitis & rectal prolapse |
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Trichuris trichiura dx?
tx? |
dx: egg ID in stool--> barrel shaped w/ bipolar mucus plugs
tx: mebendazole* or albendazole |
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What helminths cause Intestinal distress + migratory symptoms?
what indicates migration? |
-Ascaris lumbricoides -Hookworms: Necator americanus & Ancylostomas duodenale -Strongyloides stercoralis
migration Sx: serpiginous, linear, raised, tunnel-like red lesion (shows path of larva migration) palpation feels like thread w/i superficial skin |
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_____________ roundworm oral-fecal transmission (indiscriminate defecation) warm climate poor sanitation * intestinal distress + migrational sxs--> pulmonary manifestations + eosinophilia +/- intestinal obstructions +/- obstructive jaundice |
Ascariasis lumbricoides |
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Describe the pathogenicity involved in Ascariasis lumbricoides, specifically the migratory sxs |
Oral ingestion of fertilized egg--> larvae hatch in intestine--> larvae enter blood & travel to lungs--> larvae climb up the alveoli--> travel up trachea & enter esophagus--> from esophagus back to intestine--> mature into adult worm (live 1-2 yrs)
*as larvae migrate in lungs, may have CXR infiltrate in lower lobe & consecutive CXR w/ infiltrate in upper lobe |
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If a patient has a large amount of Ascariasis lumbricoides roundworms, they may present w/ malabsorption, intestinal obstruction (intertangled worms create mass), or Loeffler's syndrome.
What is Loeffler's syndrome? |
Loeffler's syndrome = acute eosinophilic pneumonia, w/ migratory pulmonary infiltrates (consecutive CXR w/ infiltrates at diff locations) & neg bacterial cultures |
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How is Ascariasis lumbricoides dx?
tx? |
Dx: ID egg in stool--> oval shaped, knobby, lumpy, bumpy
Tx: mebendazole, albendazole, or pyrantal pamoate
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_____________ & ______________ hookworms hooklets attach to small bowel & suck blood live in soil--> infection via skin penetration * intestinal distress + migratory sxs--> itchy rash, pulmonary manifestations (mild), abnormal peristalsis, & anemia |
Necator Americanus & Ancylostomas duodenale |
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Which hookworm is New world (found in Americas & Australia) & has dorsal & ventral cutting plates? |
Necator Americanus |
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Which hookworm is Old world (found in Middle East, North Africa, & South Europe) & have 4 sharp tooth-like structures? |
Ancylostomas duodenale |
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Describe the pathogenicity of hookworms |
Filariform larvae in soil penetrate skin--> get into blood--> travel to lung--> climb up alveoli & eventually reach esophagus--> swallowed in esophagus & go to intestine--> mature in small intestine--> adult worms attach & suck blood--> eggs are passed in stool--> eggs release rhabditiform larvae in soil--> develop into infective filariform larvae |
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Hookworms cause __________ d/t their hooklets |
iron deficiency anemia (microcytic)
hooklet bite marks bleed continuously & suck blood |
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How is hookworm (A. duodenale & N. americanus) dx?
tx? |
dx: ID egg in stool--> egg has thin shell & contains 2-4 cell stage
tx: correct anemia (iron & blood) + antihelminth agent (pyrantel pamoate, mebendazole, or albendazole) |
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__________ nematode transmission via skin penetration autoinfection years after primary infection (Veteran who spent time in Asia 20 yrs ago) *intestinal distress + migratory sxs--> peptic-ulcer like pain + eosinophilia, paralytic illeus, malabsorption, vomiting, diarrhea---> gram (-) meningitis |
Strongyloides stercoralis (Strongyloidiasis)
(very similar to hookworms--> penetration--> blood lung--> intestine) |
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What larvae form of Strongyloides stercoralis is responsible for autoinfection? |
rhabditiform larvae
*female attaches & penetrates duodenum--> parthenogenesis (female has eggs w/o male)--> deposits eggs w/i mucosa--> eggs hatch & release rhabditiform larvae--> larvae reenters bowel lumen--> becomes filariform larvae & reinfect (via penetration of intestine or perianal skin) |
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What can occur in immunocompromised patients w/ Strongyloidiasis? |
Severe enterocolitis (hyperinfection)--> dissemination to heart, lungs, CNS--> S. stercoralis takes gram (-) enteric bacteria w/ it upon dissemination to CNS--> gram (-) sepsis or meningitis--> possible death |
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Strongyloides stercoralis dx & tx? |
dx: ID rhabditiform larvae in stool--> short buccal cavity & large genital primordium
tx: ivermectin or thiabendazole |
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What 2 cestodes cause blood infections & have 2 intermediate hosts? |
Diphyllobothrium latum & Echinococcus granulosus |
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Which cestode? intermediate hosts= copepods & fish infectious form= procercoid (copepod)
What are the definitive hosts? |
Diphyllobothrium latum
definitive hosts= human, cats, dogs |
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Which cestode? intermediate hosts= herbivores & humans infectious form= hydatid cysts
What are the definitive hosts? |
Echinococcus granulosus
definitive hosts= dogs, wolves
*can cause granulomatous lesions & calcifications* |
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What is the only Trematode genus that is NOT hermaphroditic? |
Schistosoma
*have 2 separate sexes |
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What Schistosoma organisms live in water, penetrate skin & enter the blood stream? |
S. japonicum, S. mansoni, & S. haematobium |
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Which Schistosoma enter the mesenteric vessels & mature, eggs can cause granulomas in liver
*eosinophilia *reservoir host: cats, dogs, cattle |
Intestinal schistosomias: S. japonicum & S. mansoni |
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What Schistosoma enters & matures in the bladder veins (prostate & uterine) & can cause bladder cancer?
*Egypt & Africa *reservoir host: primates |
vesicular schistosomiasis: Schistosoma haematobium |
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Schistosoma species are dx via egg ID in stool.
If the egg is fusiform shaped w/ one pointed end, what species is it?
How is schistosoma tx? |
Schistosoma haematobium
Tx: Praziquantel |
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______________ causes Swimmer's itch ---> organism in water (great lakes) penetrate skin --> dermatitis w/ intense itching *birds are reservoir host *scuba divers
Tx?
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Non-human Schistosomes
Tx: Trimeprazine, calamine, sedatives |
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_______________ roundworms (nematodes) ingested via undercooked pork (or bear) containing cysts (encysted larvae) * intestinal distress + migratory sxs--> puffiness around eye, muscle & joint pain, SOB, eosinophilia (starting in 2nd wk) |
Trichinella spiralis (Trichinellosis) |
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Migratory sxs of Trichinellosis occur when........ ^this is reflected by an increase in IgE, eosinophils, & muscle enzymes
these are most severe if..... |
larvae migrate into muscles
life-threatening if they migrate into heart or brain |
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Trichinellosis dx & tx? |
dx: ID larvae in muscle bx (deltoid or gastrocnemius)
Tx: Mebendazole or albendazole + Immunosuppressants (corticosteroid)*
(mebendazole kills parasite--> massive immune response--> substantial damage if given w/o immunosuppressant)
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Which trematode?
infects the Lungs & CNS acquired in central america (latin america), asia, & africa |
Paragonimus |
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Which trematode?
infects Liver (biliary tract) acquired worldwide (mostly seen in US immigrants) |
Fasciola |
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ALL heminths EXCEPT ______, ______&_____can be tx w what? |
Strongyoides. stercoralis, Taenia sp. & Schistosoma sp.
mebendazole (ALL others tx w) |
