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62 Cards in this Set
- Front
- Back
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what are the next three roundworms?
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-Ascaris
-Hookworm -Strongyloides |
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Describe the life cycle identical between ascaris, hookworm and strongyloides.
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-Larvae are in blood/lymphatics.
-Larvae migrate to the lungs, alveoli, ascend respir. tract; cough up/swallow larvae into small intest. adults develop, fertilize, and ova laid there. |
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after ova are laid in intestine what happens in Hookworm?
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-Pass to feces, then to soil.
-Rhabditiform larvae hatch, feed on organic debris in soil. -Filariform larvae develop -Filariform penetrate human skin and get into bloodstream. |
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what's the infectious stage of hookworm?
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-filariform larvae
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after ova are laid in the intestine, what does Ascaris do then?
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-pass into feces/soil.
-embryonated ova are ingested by humans, pass to small intestine. -rhabditiform larvae hatch -they penetrate intestinal wall |
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after ova are laid in the intestine, what does Strongyloides do then?
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-Rhabditiform larvae hatch in intestine.
-They pass into feces, then soil. Filariform larvae develop and penetrate human skin. |
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Which two have similar entrance ways into human hosts?
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strongyloides and hookworm - both penetrate human skin.
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what is an alternate autoinfection path of strongyloides?
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-instead of developing outside of intestine, filariform larvae devel. inside.
-then penetrate intestine, and migrate to lungs. |
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what disease does Ascaris lumbracoides cause?
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ascariasis
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what is ascaris' common name?
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roundworm
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where is Ascaris found?
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warm, moist climates, esp in the Appalachian mountains
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What are the hosts of aScaris?
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humans - both children and adults.
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how long are ascaris adults?
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30 freakin centimeters! holy cow
-remember the gross white mass of wormy worms |
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how big are the ascaris ova?
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about 60 x 45 u
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what additional morphology is seen of ascaris ova?
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three stages - -corticated/decorticated fertile
-infertile |
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how big are ascaris ova that are
-corticated fertile -decorticated fertile -infertile |
Corticated and de are 45x35 to 70x50
Infertile is 90 x 40 |
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whats the main morphologic difference seen between ascaris fertile and infertili ova?
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Fertile = double hyaline shell, bile-stained, embryo does not extend to the shell.
Infertile = thin, SINGLE hyaline shell, amorphous mass extends all the way out to it. |
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Now we're talking disease;
How does symptomology in Ascariasis vary? |
By infection strength - light, heavy, and very heavy.
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What are symptoms of ascarias -light infection
-heavy -very heavy |
light: May be asymptomatic
heavy: abdom. pain, allergic symptoms (asthma, swollen lip) v. heavy: intestinal obstruction of adults that resists peristalsis |
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how is ascariasis diagnosed?
(3 signs) |
1. presence of ova in the feces.
2. possible eosinophilia 3. possible adults in stool/vomit/nasal cavity |
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how is ascariasis treated?
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pyrantel pamoate
mabendazole |
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what does pyrantel pamoate do?
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relaxes the muscles of adults so they can't resist peristalsis.
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what are the two types of HOOKWORM?
what are their common names? |
-Necator americanus
-New World hookworm -Ancylostoma duodenale -Old World hookworm |
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what are three names of diseases caused by hookworm?
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-ancylostomiasis
-necatoriasis -hookworm infection (profound) |
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Where is hookworm infection found?
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Everywhere
-endemic in chinese elderly fem. -a lot in Asia |
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what are the hosts of hookworm?
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-Humans mostly
-sometimes other primates |
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what is the hookworm ovum very similar to?
what 3 things differentiate it? |
decorticated ascaris ovum
1. ascaris has a DOUBLE hyaline sheath, hookworm's is single. 2. Hookwm is not bile-stained b/c its shell wont absorb it. 3. Hkwm has a 2-8cell embryo |
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what's less mature, rhabditiform or filariform larva?
what's the purpose/form of each? |
Rhabdit = feeding form
-has large, bulging esophagus and open buccal cavity Filarif = infective -has small esoph, buccal cav enclosed in cuticle. |
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What is the size of
-Hookworm rhabditiform larva -Hookworm filariform larva |
Rhab: 250 u
Filar: 400-600 u |
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what are 3 stages of a hkwm inf?
what are the symptoms in each? |
1. Skin penetration - local erythema, severe itching, often seen on the feet.
2. Larva lung migration: allergy symptoms 3. Adult in sm. intest: abdominal pain, diarrhea, Fe deficiency anemia |
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how is hookworm treated?
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-Mebendazole
-Pyrantel pamoate |
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What is Trichostrongylus?
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A very very rare human parasite.
OVa is similar to hookworm, but a bit longer and has multiple cell divisions per embryo (not 2-8). |
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What is the actual name for threadworm?
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Strongyloides stercoralis
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What are 2 names for the disease caused by S. stercoralis?
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-Strongyloidiasis
-Cochin-china diarrhea |
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what is the geographic distrib of strongyloides stercoralis?
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similar to hookworm - east, in asia/china, everyhwere.
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what are the hosts of s. stercoralis?
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-Humans
-Dogs -Monkeys |
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What is the ovum of S. stercoralis similar to?
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Hookworm - identical in fact.
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How do you know if you've got S. stercoralis or hookworm?
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-Hookworm is id'd by presence of ova in feces
-S. stercoralis is id'd by the presence of LARVAE in feces. |
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what's the pneumonic for remembering strongyloides' characteristics?
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Short
Sexy Slit |
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on what basis are hookwrom and stercoralis rhabditiform larva diffntiated?
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-Buccal cavity
-Genital primordium -Tail |
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What are the characteristics of hookworm and s. stercoralis
-Buccal cavity -Genital primordium -Tail |
Hookworm: long, small, pointy
Strongyl: short, large, blunt |
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what's the tail diffnc between hkwm/strongyl filariform larvae?
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Hookworm: pointed tail
Strongyl: slit tail |
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In what patients is strongyloides forced into autoinfection?
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patients on immunosuppressant therapy - not AIDS patients.
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What are the 3 stages of strongyloidiasis?
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-penetration of skin
-larval lung migration -adult in small intestine |
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what symptoms develop after adults develop in sm. intestine?
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-v. DRAMATIC inflamm response
-abdominal cramps -diarrhea w/ mucus -nausea |
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how is strongyloidiasis diagnosed?
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-rhabdit larvae in stool
-ova in duodenal intubation spec -eosinophilia maybe -anemia maybe |
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how is strongyloides treated?
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MUST USE thiabendazole, not the others.
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what nematode larvae is charactized by its tendancy to migrate from lymphatics to striated muscle?
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trichinella spiralis
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where do humans get trichinosis from?
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ingesting undercooked pork meat.
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where geographically is trichinosis found?
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worldwide
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what are the hosts of trichinella?
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humans
hogs rats bears |
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how do you identify trichinella spiralis morphologically?
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by the larva in muscle cells.
never see adults, and they don't have any ovum |
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how do trichinella reproduce?
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moms give birth to little baby trichinellas - no ovum
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what's the life cycle of trichinella?
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-hogs have it, humans ingest their muscles.
-the larvae get into the small intestine, develop into adults. -adults fertilize, females deposit larvae in lymphatics -larvae enter blood, go to striated muscle and encyst. DEAD END. |
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What are the 3 stages of trichinosis infection?
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1. Adult invasion of sm. intest
2. Migration of larvae 3. Encystation |
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What symptoms are seen in the adult stage of inf?
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nausea, diarrhea, abdom pain, but pretty vague - not diagnostic.
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what symptoms of trichinosis are seen during larval migration?
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fever - consistent, days
periorbital edema - larvae around the eyes -muscle pain -pneumonia/allergic response -petechial lesions in skin hemorrhage |
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what are 4 ways trichinosis is diagnosed?
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1. Symptoms - during stages
2. Muscle biopsy 3. WBC diff 4. Serological testing |
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what is seen in the wbc diff for trichinosis?
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-eosinophilia
-general leukocytosis |
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what 4 serological tests are done for trichinosis?
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flocculation
latex agglutination fluorescent antibody elisa |
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how is trichinosis treated?
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nothing's very good
mebendazole if anything |
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how is trichinella prevented?
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cook pork well
freeze it don't use same meat grinder as for beef. |
