Diagnostic parasitology techniques Flashcards
what are broad classifications of parasites?
endoparasites and ectoparasites
what does endoparasites break down into? (broad)
protozoa - unicellular
helminths - multicellular worms
what are the key characteristics of ectoparasites?
jointed appendages
what are common protozoal parasites in veterinary medicine?
flagellates, amoeba, ciliates, apicomplexans
what are the common helminth parasites in veterinary medicine?
trematodes (flukes), cestodes (tapeworms), nematodes
what are the common ectoparasites in veterinary medicine?
ticks, mites, lice, fleas, flies/bots
what are the possible diagnostic samples you may encounter?
feces
sputum/vomitus
blood
urine
skin scrapes
formalin-fixed tissues samples -> histopathology
what does a qualitative test tell you?
wether an animal is infected
what does a quantitative test tell you?
tells you the amount affected
what are qualitative tests to diagnose endoparasites for feces?
direct visualization
direct smear
concentration techniques - fecal flotation, fecal sedimentation, baermann, immunoassays, polymerase chain reaction (PCR), culture of eggs or larvae
how do you get a parasitologist to tell you what the parasite it?
save in 70% ethanol and submit to veterinary diagnostic lab
what type of parasites get expelled in the feces or vomitus?
adult endoparasites
how do you prepare a direct fecal smear?
drop of saline + small amount of fecal material + coverslip
what has a risk for false negatives and is not a great tool for detecting most GI parasites?
direct fecal smear
what test is most useful when observing the motility of protozoal parasites that have motile stages?
direct fecal smear
what must the fecal flotation have for the most common parasites eggs/cysts to float?
higher/heavier specific gravity than most common parasites eggs/cysts
what is a good test for nematode eggs?
fecal flotation
what test is used to detect eggs/cysts that are too heavy to concentration by fecal flotation?
fecal sedimentation
what test is most useful for non-nematode eggs and certain protozoal cysts?
fecal sedimentation
what are some non-nematode eggs that fecal sedimentation are useful for?
trematode or acanthocephalan
what are some certain protozoal cysts that fecal sedimentation are useful for?
amoebae, ciliates, Giardia spp.
what is the fecal sedimentation not sensitive for?
nematode eggs or coccidian oocysts
what is the baermann technique useful for?
nematode larvae
How does the Baermann technique recover nematode larvae?
nematode larvae will wiggle out of biological material, cannot swim against gravity and will fall through the water to the area of clamped off tubing