Anal Discomfort Flashcards
Enterobius vermicularis
Anal Discomfort Pinworms MOI -*Ingestion of eggs -fecal oral Human Stage -Female worm migrates out anus & lays eggs on perianal skin, causing itching Disease -causes *Enterobiasis -*Anal pruritus at night Diagnosis -*Scotch Tape test w/ microscopy for eggs (*ovoid and flat on one side)
Trichuris trichiura
Anal Discomfort
Whipworms
MOI
-Ingestion of eggs from fecally contaminated soil or food
Human Stage
-Worms in colon may cause rectal prolapse
Outside Human
-Eggs survive in environment
Disease
-causes Trichuriasis
-Diarrhea, cramps; blood in stools; anemia; tenesmus, rectal prolapse
Diagnosis
-Stool exam for O&P (lemon-shaped eggs)(*football shaped?)
Ascaris lumbricoides
Anal Discomfort
Giant Roundworm
MOI
-Ingestion of eggs from fecally contaminated soil or food
Human Stage
-Larvae migrate to lung, causing pneumonia
Outside Human
-Eggs survive in environment
Disease
-causes Ascariasis
-Pulmonary larval migration (cough and eosinophilia); intestinal discomfort; obstruction of a viscus, or intestinal perforation
Diagnosis
-Stool exam for O&P (scalloped, oval eggs)
Ancylostoma duodenale
Necator americanus
Anal Discomfort
Hookworms
MOI
-Larvae in soil penetrate skin
Human Stage
-Worms in colon cause blood loss (anemia)
Outside Human
-Egg→rhabditiform larvae (noninfectious, feeding)→*filariform larvae (infectious, nonfeeding)
**secretes anticoagulant
Disease
-causes *Necator americanus
-“Ground itch”; pulmonary larval migration (cough and eosinophilia); diarrhea, abdominal discomfort; anemia; hypoproteinemia; occult blood in stools
Diagnosis
-Stool exam for O&P (oval segmented thin shelled eggs)
Strongyloides stercoralis
Anal Discomfort
Threadworms
MOI
-Larvae in soil penetrate skin and (rarely) internal auto-infection
Human Stage
-Worms disseminate to various tissues in immunocompromised (auto infection)
Outside Human
Egg→rhabditiform larvae→filariform larvae; also “free living” cycle in soil
Disease
-causes *Strongyloidiasis
-Skin rash at site of infection *“ground itch”; *pneumonia; *diarrhea, abdominal discomfort; persistent *eosinophilia
Diagnosis
-Stool exam, sputum, bronchial lavage for O&P (larvae)
Toxocara canis
Anal Discomfort
Dog roundworm
MOI
-Ingesting eggs in soil contaminated by dog feces; eating undercooked meat containing larvae cysts
Human Stage
-Larvae in internal organs
Outside Human
-Adult worms in dog intestine→eggs
Disease
-causes Toxocariasis; Visceral or ocular larva migrans
-Hepatosplenomegaly, wheezing, fever, ocular involvement (*leukocoria)
Diagnosis
-Medical history, physical exam, Serology; eosinophilia
Trichinella spiralis
Anal Discomfort MOI -Eating undercooked, infected pork or other animal (larvae cyst) Human Stage -Larvae encyst in muscle causing myalgia Outside Human -Larvae in muscle of pig, bear, and other animals Disease -causes *Trichinosis -Nausea, fatigue, abdominal pain, then muscle soreness, weakness Diagnosis -Serology and muscle biospy (larvae)
Taenia saginata
Anal Discomfort Beef tapeworm -has 4 suckers but no hooklets MOI -Ingest larvae in undercooked beef Human Stage -Adult tapeworm in intestine Outside Human -Larvae in muscle of cattle Disease -Epigastric pain, vomiting, diarrhea; *pruritus ani Diagnosis -Proglottids in stool
Taenia solium
Anal Discomfort Pork tapeworm -has four suckers and circle of hooks MOI A. Ingest larvae in undercooked pork B. Ingest eggs from human feces in contaminated food or water Human Stage A. Adult tapeworm in intestine B. Cysticerci in brain, skin & eyes Outside Human -Larvae in muscle of pig Disease **Taeniasis = adult tapeworms in small intestines A. Epigastric pain, vomiting, diarrhea **Cysticerosis = larvae develop in eyes, muscles or brain B. Muscle pain & weakness; ocular & neurologic problems, epilepsy Diagnosis A. Proglottids in stool B. Biopsy, CT scan
Diphyllobothrium latum
Anal Discomfort
Fish tapeworm
-has 2 elongated sucking grooves (no hooklets) w wide proglottids containing “rosette-shaped” uterus
MOI
-Ingest larvae in undercooked fish
Human Stage
-Adult tapeworm in intestine can cause vitamin B12 deficiency
Outside Human
-Larvae in body cavity of copepod→larvae in muscles of freshwater fish
Disease
-Abdominal pain, weight loss, anorexia, malnutrition, B12 deficiency
Diagnosis
-Operculated eggs in stool
-oval yellow/brown eggs
-has an *operculum (hatch)
Echinococcus granulosus
Anal Discomfort
Cystic echinococcosis
MOI
-Ingest eggs in food contaminated with dog feces; direct contact with infected dogs
Human Stage
-*Hydatid cysts, especially in liver and lung
Outside Human
-Adult tapeworm in dog intestine produces eggs
Disease
-unilocular hydatid cyst disease
-Large cysts produce various symptoms, usually in lungs or liver
Diagnosis
-CT scans, MRI, x-rays, serology
