Parasitology Flashcards
list some techniques for parasitology dx
fecal float
fecal PCR
necropsy
blood smear
skin scraping
what test is recommended for recovering a nematode larvae from feces
Berman test for larvae
what is the fecal test recommended for recovering nematode eggs?
fecal float
what is the disadvantage of morphological tests for parasitology diagnosis?
requires trained technicians
samples for fecal exams should be __ and at least __ g
samples for fecal exams should be fresh and at least 3g
a direct saline smear uses a tiny amount of feces mixed with a drop of saline which can detect __ because they move such as _ and __. This technique is not for __.
a direct saline smear uses a tiny amount of feces mixed with a drop of saline which can detect protozoan trophozoites because they move such as giardia and trophozoites. This technique is not for cysts.
when doing a routine fecal flotation, always __.
centrifuge
direct smear sensitivity
low -> alot of false negatives
direct smear specificity
high if person is well trained, low if they’re not trained well
giardia is best detected in what solution?
zinc sulfate
zinc sulfate has a specific gravity of __ while sheathers solution has a specific gravity of __
zinc sulfate has a specific gravity of 1.18-1.2 while sheathers solution has a specific gravity of 1.25-1.28
T/F: sheathers solution gets the most things but is sticky
T
how can sensitivity be improved in a fecal exam?
repeat the test or combine with another test (giardia antigen test)
spurious parasites
things that are parasites of other animals and show up in samples because of coprophagy or predation. increases false positives and decreases specificity
common helminths are > __um and common protozoa are < __um
common helminths are > 40 um and common protozoa are < 60 um
