Term
| enterobius vermicularis (pinworm) may cause infection in 3 places other than rectum. |
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Definition
| appendicitis, vulvovaginitis, UTI |
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Term
| sx of whipworm infection (light, regular, heavy) |
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Definition
| light - asymptomatic; regular - abdominal pain, nausea, diarrhea, anemia, eosinophilia; heavy - prolapsed rectum |
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Term
| what causes anemia in whipworm infection? |
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Definition
| trichuris adults attach to mucosa, drink blood in small amounts, detach and reattach somewhere else, leaving open bleeding wound --> blood loss --> anemia |
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Term
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Definition
| microscopic examination of feces for barrel shaped eggs with mucus plug at each end |
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Term
| normal serum IgE and no eosinophilia |
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Definition
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Term
| adult worms NOT attached to gut wall |
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Definition
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Term
| what are the 4 mechanisms of pathogenesis in ascaris lumbricoides |
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Definition
| 1 mechanical and immune-mediated damage during migration of larvae through lungs (fever, cough, atypical pneumonia like sx) 2. allergic manifestations common (increased IgE and eosinophilia) 3. adults in bowel (lots) pain or obstruction 4. adults may increase motility and damage tissues when drugs are given or during fever |
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Term
| diagnosis of ascaris lumbricoides |
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Definition
| larvae and eosinophils in sputum; eggs in feces (fertilized round with embryo; unfert elongated); adults emerge from orifices! |
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Term
| males have unique posterior copulatory bursa |
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Definition
| hookworm (ancylostoma, necator) |
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Term
| transmission requires warm, moist climate |
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Definition
| hookworm and strongyloides (allows eggs to hatch in soil and larvae to develop) |
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Term
| pathogenesis/sx of hookworm inf |
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Definition
| skin penetration causes rash (esp in previously sensitized persons); pulmonary manifestations; hypochromic anemia and hypoproteinemia d/t chronic blood loss |
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Term
| diagnosis of hookworm inf |
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Definition
| eggs in feces (identical in ancylostoma and necator) |
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Term
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Definition
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Term
| what sets strongyloides apart from hookworms and ascaris? |
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Definition
| larvae passed in stool (vs eggs) |
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Term
| how do people come into contact with strongyloides? |
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Definition
| barefeet in contaminated soil, person to person transfer of filariform larvae when they develop in the gut or perianal region |
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Term
| immunosuppressed suffer from continued autoinfection and hence hyperinfection |
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Definition
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Term
| pathogenesis of strongyloides |
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Definition
| skin lesions assoc with reinfection of allergic host; pulmonary disease; GI sx dependent on worm load and immune status of host (diarrhea, ab pain, malabsorption), hyperinfections through autoinfection leading to large worm burden and disseminated infection in immunocompromised (bacteremia) |
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Term
| diagnosis of strongyloides |
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Definition
| demonstration of rhabditiform larvae in stool (prominent genital primordium and bulbar esophagus); filariform larvae may be found in feces of pts with autoinfection; larvae and eosinophils in sputum of immunocompromised |
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Term
| enterobius vermicularis life cycle |
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Definition
| adult males and females reside in cecum --> copulation --> females migrate to perianal skin and release eggs by uterine contraction or dessication --> eggs become airborne from bedding and may be ingested --> eggs hatch in small intestine and larvae migrate to cecum becmoing adults in 2-4 weeks after infection |
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Term
| pathogenesis of enterobius vermicularis |
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Definition
| no serious disease in light infection; perianal itching; appendicitis, vulvovaginitis, UTI |
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Term
| diagnosis of enterobius vermicularis |
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Definition
| clinical hx; eggs (less commonly adult worms) in perianal region (scotch tape techinque) |
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Term
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Definition
| gravid females attached to cecal mucosa --> lays eggs into lumen --> eggs passed in stool --> eggs mature in soil in 10 days --> ingestion of embryonated eggs --> new infection |
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Term
| ascaris lumbricoides life cycle |
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Definition
| ingested embryonated eggs hatch in sm int --> larvae penetrate mucosa --> carried by portal system to rt heart --> larvae carried to lungs, break into alveoli, coughed up, swallowed, to small int --> become adults (mature) in 8-10 wks (NOT attached to mucosa) --> mate in small int, lay 200,000 eggs per day --> adults can survive 1 year or more, passed in feces, eggs passed in feces, must mature in soil 10 days to be infectious |
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Term
| what are the distingiushing features of hookworms? |
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Definition
| mouth structures and posterior copulatory bursa (males). ancylostoma have teeth, necator have cutting plates in the buccal cavity |
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Term
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Definition
| mature eggs hatch in soil releasing active, free-feeding rhabditiform larvae --> become non-feeding infective filariform larvae --> penetrate skin (feet) --> migrate to heart, then lungs, penetrate alveoli, coughed up, swallowed --> mature in small bowel where they grasp a villus with mouth |
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Term
| life cycle of strongyloides |
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Definition
| female lays eggs in mucosa --> hatch and produce rhabditiform larvae --> 1. can transform into filariform larvae in soil, penetrate skin and cause hookworm-like infection 2. rhabditiform larvae can trasnform into infective filariform larvae in the colon and penetrate gut wall or perianal skin --> initiate a new cycle 3. rhabditiform larvae passed in feces --> develop into adults --> produce eggs --> rhabditiform larvae --> filariform larvae produced |
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Term
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Definition
| trichinella spiralis (gives birth to a second stage larvae which penetrates gut wall and encysts in skeletal muscle) |
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Term
| life cycle trichinella spiralis |
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Definition
| eat inadequately cooked pork --> larvae encyst in stomach and mature in small intestine 2-6 days --> burrow into mucosa (female does. male is expelled after mating) --> female lay 1000-1500 larvae for 1 month --> larvae penetrate lymphatics of sm int and are hematogenously disseminated throughout the body --> larvae enter striated muscles where they encyst (diaphragm, intercostal muscles, tongue) --> encysted larvae calcified in 6-9 months and remain infective for 5-10 yrs |
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Term
| pathogenesis/sx of trichinella spiralis |
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Definition
| dependent on # of larvae ingested and host's IR. mild enteritis during mating and larvasporation; damage to muscle cells during invasion; severe muscle pain and tenderness, high fever, myocardial damage (CHF), over 1000 larvae/gm muscle = very seirous disease; striking eosinophilia (15-50%); major lesions caused by massive ag-ab rxn which occur after host is sensitized 10-14 days after tissue invasion; similar to those seen in serum sickness, IC disease, IgE mediated lesions, localized edema, hives, rashes, fever. major ag = worm secretions |
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Term
| how do pigs become infected with trichinella |
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Definition
| eating rats or infected meat scraps |
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Term
| can humans transmit trichinella to each other? |
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Definition
| no, humans are dead end hosts except among cannibals -_- |
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Term
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Definition
| hx, clinical picture, marked eosinophilia, demonstration of larvae in muscle bx, serologic tests |
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