Parasitic Infections Flashcards
Amoebiasis?
Entamoeba histolytica: cysts that are viable in the soil and water for wks to mnths
how are amoebia cysts transmitted?
fecal to oral, fly droppings, or human to human contact; humans are the only hosts
what is the pathophys behind amoebiasis?
- cysts pass through to the intestines where they hatch
- trophozites invade the mucosa and induce necrosis
where are amebic ulcers most likely to be found?
mebic ulcers are typically flask shaped and occur anywhere in the large bowel or termical ileum
how deep do amebic ulcers go?
typically limited to the muscularis, but can penetrate the serosa
what are complications of amebic ulcers?
if they penetrate the serosa, may cause perforation, abscess, or peritonitis
what are some clinical finding of an amebic infection?
- intestinal
- colits
- extratestinal dz
what are sx of intestinal dz?
often asx
what are sx of amebic colitis?
-mild to moderate (few seimformed stools w/o blood) or SEVERE DYSENTERY (greater number of liquid stolls streaked with blood ro bits of necrotic tissues
what are some pt complaints in an amebic colitis? severe dz?
- cramps, fatigue, weight loss, increased flatulence
- cycles of remission and recurrence are tyical
-severe: prostrate and toxic with fever, colic, tenesmus, and vomiting
what may physical exam reveal in amebic infxn? (colitis)
distention, hyperperistalsis, generalized abdominal tendernes
what are some complications of amebic colitis?
appendicitis, bowel perforation, fulminant colitis, massive mucosal sloughing, hemorrhage
what do localized ulcerative lesions of the colon and localized granulomatous lesions of colon potentially cause?
pain, intestinal obstruction, hemorrhage
what is an ameboma?
a localized granulomatous lesions of the colon
what must amebomas be differentiated from?
colon cancer, TB, or lymphogranuloma venereum (via bx that will reveal granulation tissue)
what can extraintestinal amebic dz cause?
hepatic amebiasis and amebic liver asscess:
can be asx or result in sx either suddenly or gradually over days to months
what are findings of a extraintestinal amebic dz?
fever, pain, tender hepatomegaly, malaise, prostration, sweating, chills anorexia and weight loss
what other signs may pts with EI amebic dz present with?
think LUNG
coughing and right lower lung findings: if abscess is in the superior liver
what is a complication of amebic abscess?
can rupture and spill into the pleural, peritoneal, or pericardial space which can be fatal
where else and amebiasis present? (rare)
metastasize to lungs, brain, or genitalia
diagnostic studes for amebic dz?
- stool specimens
- sigmoidoscopy, colonoscopy, rectal biopsy
- serology
- CBC
- US, CT, MRI
what will stool specimens reveal in amebic dz
reveal cysts or trophozoites
what will scopies and bxo of rectum reveal?
ulcers; if collection of exudates found need to be examined for trophozoites
what will serology show in amebic dz?
-can detect antiboides of up to 10 years after infection, so can’t be used to differenctiate past from prsent infxn