parasit. Flashcards
(30 cards)
cryptosporidiosis diarrhea
profuse, water, self-limiting, more sever in AIDS
cryptosporidiosis treatment
none
crypstosporidiosis auto infection
20% thin wall cysts
crypstosporidiosis stain
ziehl-nilsson, modified acid-fast smears(won’t see on trichrome)
crypto/giardia dfa
fluorescent antibody test (use formalin), HIV services
most specific/sensitive
cyclospora cayatanensis
fecal-oral FOOD and water, nausea diarrhea, anorexia
parasitology autofluorescence
cyclospora (size important), isospora belli
crypto/cyclo oocysts
crypto (8-10 um) cyclo (4-6 um)
isospora bell
diarrhea, abdominal pain, ONLY COCCIDIAN PARASITE IN WHICH MAN IS DEFINITIVE HOST, oocysts not immediately infectious (unsporulated when passed)
isospora diagnosis
zn- acid fast
auramine-rhodamine
oocysts best iseen in whet prep
sarcocystis bovihominis/suihominis
cow and pig (wide range of mammalian and avian hosts (humans can be intermediate or definitive (multiplies asexually)
micrsporidia
emerging infection of AIDS patients (obligate intracellular parasite) polar tubue-extrusion mechanism for injecting spore contents, NO OOCYST
microsporidium genera
encephalitozoon, nosema, pleistophora, enterocytozoon, septatat, vittaforma, trachipleistophora (enterocytozoon bieneusi)
microsporidia diagnosis
modified trichrome (belt-like stripe)
modified gram stain
giemsa
calcofluor
microsporidia key points
30% of AIDS, modified trichrome difficult to interpret
mAB improve sens/spec.
toxoplasma
ingestion of infective oocysts, or tissue cysts in meat, transplacental, blood transfusion, organ transplant
cat definitive host (excretes oocysts
toxo stages
tachyzoites, bradyzoites, oocysts
toxoplasma stain
giemsa
toxo morphology
crescent shape, 2-3 x 4-8
bradyzoites in cysts seen with PAS stain (periodic acid Schiff)
toxo serology
1: 16-1:64- past exposure/early disease
1: 256- recent exposure
1: 1024 significant infection
pneumocystis jiroveci
disease: pcp
acquired: unknown environmental
leading cause of death in AIDS
pneumocystis forms
cysts, sporozoites, trophozoites
cysts contain 8 sporozoites which mature into trophozoites, before encysting and repeating the cycle
pneumo specimens
respiratory (sputum)
stain cyst: toluidine blue ) methenamine silver nitrate, crystal violet, calcofluor
Troph: Giemsa/WRight
DFA
Naegleria fowleri
primary amoebic meningoencephalitis
acquired: water exposure (headache, vomiting, fever, confusion, seizures
site: CSF/brain (no other organ involvement)