Parasitology II lecture – Flashcards
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| What's the scientific name for pin worm? |
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| enterobius vermicularis |
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| What's the scientific name for whip worm? |
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| trichuris trichiura |
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| What's the scientific name for a large roundworm? |
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| ascaris lumbricoides |
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| What's the scientific name for hookworm? |
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| necator americanus or ancylostoma duodenale |
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| How many eggs does the female pinworm lay and where does she lay them? |
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| 20,000 eggs perianally |
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| Enterobius vermicularis causes what diseases in the female genital tract? |
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| vaginitis, granulomatous endometritis or salpingitis |
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| What is the treatment for enterobius vermicularis? |
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| pyrantel pamoate, mebendazole, and albendazole |
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| How do you prevent enterobius vermiculars infection? |
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| trim fingernails short, wash hands thoroughly, eggs are sensitive to sunligh, open curtains in daylight |
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| T/F In the case of Enterobius vermicularis infection you treat all family members simultaneously |
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| true |
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| Where does the female trichuris trichura lay eggs? |
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| 3,000 to 10,000 in the feces daily |
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| How big are adult whipworms? |
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| 30-50mm |
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| How big are adult female pinworms? |
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| 10mm |
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| What are the symptoms of moderate infection of trichuris trichura? |
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| damage to intestinal mucosa, nausea, abdominal pain, diarrhea, stunted growth |
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| What are the symptoms of heavy infection with trichuris trichura? |
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| significant mucosal damage, blood loss/anemia and colonic or rectal prolapse **colonic ulceration may allow bacteria to enter bloodstream which is fatal |
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| How do you diagnose trichurs trichura? |
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| microscopic identification in stool. Eggs easily visible in symptomatic cases. Also look for eosinophilia. |
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| How do you treat trichuris trichura? |
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| mebendazole and albendazole |
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| How big are adult ascaris lumbricoides? |
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| 15-40 cm long |
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| How big are adult ascaris lumbricoides? |
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| 15-40 cm long |
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| Describe the size and shape of ascaris lumbricoides eggs? |
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| elliptical (35 x 55 um) with rough coat |
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| What are the symptoms of heavy ascaris lumbricoides infection? |
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| fever, wheezing, SOB, abdominal pain, malabsorption of food, intestinal obstruction (due to worm bolus) |
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| Ascaris lumbricoides can migrate to what sites in the body other than intestine? |
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| appendix, bile duct, or pancreatic duct |
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| What is a sign of ascaris lumbricoides in poorly nourished children? |
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| growth retardation |
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| T/F Infection with ascaris lumbricoides can result in deaht from respiratory failure. |
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| true but very rare |
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| Which worm will attempt to exit the body when the patient has a high fever? |
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| ascaris lumbricoides |
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| HOw do you diagnose ascaris lumbricoides? |
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| identification of eggs in feces and finding larvae and eosinophils in sputum |
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| How many people in the US are infected with enterobius vermicularis? |
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| 30-40 million |
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| Mebendazole is used for what infections? |
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| pin, whip, round, tape and hook |
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| Albendazole is used for what infections? |
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| round, tape and fluke |
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| Adult trichuris trichiura live in the _____. |
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| cecum (larvae hatch in the small intestine) |
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| What do you use for treatment of ascaris lumbricoides? |
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| mebendazole and albendazole are preferred if pt also has trichuris trichiura also, pyrantel pamoate |
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| What do the adult necator americanus look like? |
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| 10mm pinkish-white, hook shaped, 2-14 year lifespan |
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| What does necator americanus feed on? |
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| worms attach to mucosa of small bowel to suck blood |
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| How many eggs does the necator americanus female release daily? |
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| 10,000-20,000 |
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| How big are necator americanus eggs? |
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| 40-60 um |
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| What are the symptoms of necator americanus? |
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| mostly asymptomatic. "ground itch" on soles of feet for several days, gastric pain, blood loss, eosinophilia in gut and periphery. Pulmonary manifestations similar to ascaris infection; less freqent, less severe |
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| Hypoalbuminemia is comon when you are infected with which helminth? |
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| necator americanus |
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| Severe anemia caused by necator americanus can cause _______ in children. |
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| heart failure; also may retard physical/mental/sexual development |
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| Where in the body is the adult necator americanus located? |
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| mucosa small bowel |
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| Where do ancylostoma duodenale eggs hatch? |
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| eggs hatch and larvae grow in teh feces/soil |
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| What stage of ancylostoma duodenale is infected? |
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| third-stage larvae |
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| Where does Ancylostoma infect? |
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| larvae penetrate skin, carried through blood vessels to heart, then to lungs, coughed up a swallowed. Then mature to adults in small intestine |
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| How do you diagnose ancylostoma duodenale? |
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| examine stool for worm eggs (may be need to be concentrated) Egg count indicates worm burden and if stool stands for too long eggs may hatch into larvae |
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| The eggs of which two helminths are indistinguishable? |
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| N. americanus and A. duodenale |
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| How do you treat necator americanus? |
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| mebendazole, albendazole, and pyrantel pamoate |
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| How do you prevent being infected with necator americanus? |
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| wearing shoes, practicing good sanitation |
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| How big are adult strongyloides stercoralis? |
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| 2mm |
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| How does strongyloides stercoralis infect its host? |
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| infective filariform larvae penetrates intact skin initiating infection-->circulatory system--> lungs --> coughed up--> swallowed |
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| How does necator americanus infect host? |
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| larvae penetrate skin, enter bloodstream, reach heart, lung capillaries, alveolar spaces, are coughed up then swallowed, mature in small intestine |
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| Which worms are coughed up only to be swallowed? |
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| ascarius lumbricoides, strongyloides stercoralis, ancylostoma duodenale, necator americanus |
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| Where does strongyloides stercoralis lay its eggs? |
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| gravid female penetrates the mucosa of the duodenum to deposit eggs |
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| What are the two cycles by which strongyloides stercoralis can infect host? |
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| direct cycle (similar to hookworm) and autoinfective cycle: larvae invade internal mucosa (internal) or peri-anal skin (external) |
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| What are the GI symptoms of strongyloides stercoralis? |
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| GI- usually asymptomatic, heavy load causes epigastric pain/tenderness made worse by food intake also peptic ulcer-like pain with peripheral eosinophilia. Also, vomiting, diarrhea, malabosprtion may be seen with heavy mucosal damage |
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| What are the pulmonary symptoms of strongyloides stercoralis |
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| fever/coughing/wheezing/burning in chest/shortness of breath (similar to ascariasis) |
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| What disease has the halmark of peptic ulcer like pain with eosinophilia? |
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| strongyloides stercoralis |
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| What helminth causes raised red serpinginous (creeping) lesions over buttockes/lower back and why? |
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| strongyloides stercoralis due to external autoinfection arising from larval invasion of peri-anal area |
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| How do you diagnose strongyloides stercoralis? |
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| indentify larvae in fresh stool. if absent from stool, look in duodenal aspirates, jejunal biopsies Also, can identify larvae in sputum/may culture on agar plates ELISAs |
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| What is the larva currens? |
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| a red line on skin that moves (~5cm/day) then disappears when you become infected with strongyloides stercoralis |
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| What is the treatment for strongyloides stercoralis? |
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| ivermectin and thiabendazole |
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| How do you prevent strongyloides stercoralis infection? |
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| good sanitation, avoid fecal contamination of water/soil/food |
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| What type of drug is ivermectin? |
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| broad spectrum anti-parasitic |
