Lecture 4: Diagnostic and Treatment Flashcards
What are the 3 broad classifications of parasites
Protozoa, helminths, and ectoparasites
Are Protozoa and helminths ecto or endoparasites
Endoparasites
Are Protozoa unicellular or multicellular
Unicellular
Are helminths multicellular or unicellular
Multicellular
Ectoparasites have ___ appendages
Jointed
What are the 4 common Protozoal parasites in veterinary medicine
- Flagellates
- Amoeba
- Cilliates
- Apicomplexans
Giardia and tritichomonas are what type of Protozoal parasite
Flagellates
Acanthamoeba and entaemoeba are what types of protozoal parasites
Amoeba
Balantidium coli and ichtyhophthirius multifillis are what type of protozoal parasite
Cilliates
Toxoplasma gondii, sarcocystis neurona, neospora caninum, cryptosporidium spp, babseia, coccidia (elimeria, isospora) are what types of protozoal parasites
Apicomplexans
identify the type of protozoal parasite 1-4
- Flagellates
- Amoeba
- Cilliates
- Apicomplexans
What are the three common types of helminths classes in veterinary medicine
- Trematodes (flukes),
- cestodes (tapeworms)
3.nematodes
Fasciola hepatica, fascioloides magna, and paragonimus kellcoti are examples of what type of helminths parasite
Trematodes (flukes)
Dipylidium caninum, Taenia spp, echinococcus spp, and moniezia are what types of common helminths parasites
Cestodes (tapeworms)
Anycylostoma spp, strongylus spp, Haemonchus contortus, ostertagia ostertagi, roundworms (ascaris spp, toxocara spp, parascaris equorum) are examples of what types of common helminth parasite
Nematodes
What are the 5 common ectoparasites in veterinary medicine
Ticks, mites, lice, fleas, fleas/ bots
Rhipicephalus sanguineus, amblyomma americanum. Ixodes scapularis, and dermacenter variabilis are examples of what type of common ectoparasites
Ticks
Sarcoptes scabiei, demodex canis, cheyletiella spp, otodectes cyonotis are examples of what type of ectoparasites
Mites
Linognathus spp, haematripinus spp, trichodetes canis, folio cola subostratus, damalinia spp. are examples of what type of ectoparasites
Lice
Are the following lice bloodsucking or chewing: Linognathus spp, haematripinus spp
Blood sucking
Are the following lice bloodsucking or chewing: trichodetes canis, folio cola subostratus, damalinia spp.
Chewing
Ctenocephalides are examples of what type of ectoparasite
Fleas
Gasterophilus intestinal is, cuterebra cuniculi, melophagus ovinus are examples of what type of ectoparasite
Flies/bots
What are the concentration techniques in diagnosing endoparasites in feces
Fecal flotation, fecal sedimentation and baermann
What do qualitative tests help you determine and what don’t they conclude
Tests help you determine if an animal is infested but doesn’t tell you the degree of infection
What are the 5 techniques for feces endoparasites: qualitative
- Direct visual in feces
- direct fecal smear
- Fecal float
- Fecal sedimentation
- Baermann
Direct fecal smears are not great for detecting
Most GI parasites
What is direct fecal smear most useful at detecting
Observing the motility of protozoal parasites that have motile stages- ex: giardia or tritichomonas
The fecal flotation solution used must have a ____ specific gravity than most common parasites or egg/cysts
Higher
Higher specific gravity of flotation solution allows the eggs/cysts to ____
Float to the top of solution
What is a common floatation solution used
Zinc sulfate or sucrose
When are fecal sedimentation tests used
To detect eggs/cysts that are too heavy or delicate to concentrate by fecal flotation
What type of parasites are fecal sedimentation tests most useful at detecting
Non-nematode eggs: Trematodes and acanthocephalan
Certain protozoal cysts: amoebae, ciliates, Giardia spp
What is the baermann technique useful for recovering
Nematode larvae from samples that relies on their motility
What is the theory behind the baermann technique
Nematode larvae will wiggle out of the biological material, can’t swim against gravity and will fall through water to the area of clamped off tubing
What is the baermann technique useful for detecting
Lung worms and strongyloides
The baermann technique is useful at detecting what parasites in cats
Aelurostrongylus abstrusus (terminal airways/lungs)
What is the baermann technique useful at detecting in dogs
Crenosoma vulpis, angiostrongylus vasorum, strongyloides sterocoralis
What is the baermann technique useful at detecting in ruminants
Dictyocaulus spp
What parasites it the baermann technique not preferred in dogs, use flotation technique
Filaroides hirthi, filaroides osleri, eucoleus
What is a direct smear indicated for diagnosing endoparasites
Protozoal GI infection that has motile stages (ex: Giardia and tritichomonas spp)
What are the cons to direct smear
Not very sensitivity, do not use as primary diagnostic tool
When is a fecal flotation test indicated for diagnosing endoparasites
Nematode infection that produces eggs/cysts
What are the cons of fecal flotation
Some eggs and cysts are too heavy to float- use fecal sedimentation
When are fecal sedimentation tests indicated for diagnosing endoparasites
Infections with Trematodes, ancanthocephalans, amoebae, ciliates, Giardia
What are the cons of fecal sedimentation
Not very sensitive for nematode eggs or coccidian oocysts
When is the baermann test indicated for diagnosing endoparasites
Motile larvae will be present in feces- lung worm or strongyloides spp
What are the cons of the baermann test
Only useful for isolating motile larval stages
How can immunoassays diagnose endoparasites in feces: qualitative examination
Detection of antigens in feces
How does PCR diagnose in feces
Detection of parasite DNA
What parasites are immunoassays most commonly used for
GI protozoal parasites- Giardia and cryptosporidium
What parasites does PCR detect
GI protozoal parasites Giardia and cryptosporidium
What will quantitative test indicate
Indicate negative or if detected and if detected a Ct value
What does a Ct value determine
Burden of infection
Low Ct value=
Higher burden
In order for a culture of eggs or larvae to get exact speciation what larvae stage must the nematode be at
L3
Culturing of eggs or larvae is commonly used when
For trichostrongyles and stronglyes that commonly infect large animals
What is a common technique for diagnosing endoparasites in feces quantitatively
Dilution egg counts
What are dilution egg counts good at detecting
Trichostrongyle/strongyle in ruminants and horses
Why use a quantitative test not qualitative test in large animals
Large animals almost always have low levels of egg shedding unless they are actively being treated, therefore the question is not are they infected but the degree to which they are infected
How does the Cornell-McMaster dilution egg count technique work
Quantify eggs within a diluted fecal sample that is further diluted (1:1) in fecal flotation solution
Provides an estimate of eggs/gram of feces
Why does the Cornell-McMaster technique dilute with flotation solution
- Dilution decreases number of eggs you must count—> enhances accuracy
- Flotation solution allows the eggs to float to to of chamber, floating above fecal debris
What are the 4 common types/classifications of eggs
- Nematode
- Trematodes
- Cestodes
- Protistan cysts and oocysts
What are the 4 types of nematodes
- Ascaridoid
- Strongyle type
- Trichuroid
- Oxyurid
Round worms are what type of nematode
Ascaridoid
Hookworms, strongyle, and trichostrongyles are what type of nematode
Strongyle-type
Trichuris spp (whipworms) and capillarids (eucoleus spp) are examples of what type of nematode
Trichuroid
Pinworms are what type of nematode
Oxyurid
What are the general characteristics of Ascaridoid (roundworms) on histology
Light brown to brown, round to oval, thick wall
What type of endoparasites is this
Ascaridoid eggs/roundworm eggs (nematodes)
What is the public health significance of toxocara or bayliscascaris procyonis
Toxocara ocular larval migrants in humans
Baylisascaris procyonis is a neurotropic parasite- cerebral larval migration
What are the general characteristics of strongyle type nematodes
Elongated oval, thin wall, clear, embryonated
What is the following endoparasite
Strongyle type- nematodes
What are the general characteristics of Oxyurid eggs/pinworms
Colorless shell and small operculum (cap) on one end
what endoparasite is this
Oxyurid egg/pinworms (nematode)
What are the general characteristics of Trichuroid eggs (ex: whipworms)
Bipolar plugs (bioperculated), elongate to barrel shape, smooth thick wall
What type of endoparasite is this
Trichuroid egg- whipworms egg (nematode)
What kind of technique would work best to isolate Trichuroid eggs
Fecal flotation
What are the general characteristics of Trichuroid egg: capillarids (whipworms lookalike)
Bipolar plugs less prominent than whipworms and slight curved appearance, can have pitted irregular shells
Identify the following endoparasite
Trichuroid egg- capillarids (nematode)
What are the general characteristics of trematode eggs
Brown egg with an operculum
What kind of technique would work best to isolate the Trematodes egggs
Fecal sedimentation
what type of endoparasite is this
Trematode eggs
What are the general characteristics of cestodes eggs
Embryonated, 6-hooked oncosphere present inside a thick striated shell, outer shells can vary
identify the endoparasite
Cestode eggs
What are the general characteristics of protistan cysts and oocysts
Smaller than most other eggs (4-30 microns)
identify the endoparasite. Which are cysts and which are oocysts
Protistan cysts- left 2
Protistan oocysts- right 4
What are the 3 common techniques for blood parasites
- Direct blood smears
2.immunoassays - Microfilaria concentration techniques:
- modified knot’s
- millipore filter test
What is the direct blood smear typically used for
Identify circulating microfilariae, Protozoa, and rickettsia (bacteria)
Identify the parasite in blood smear
dirofilaria immitis
identify the parasite in blood smear
Babesia canis
What is the preferred microfilaria concentration technique
Modified knots
How does microfilaria concentration technique work
Concentrate/filter the loop to increase likelihood microfilaria will be visualized. Usually involves losing RBC
When do you do a microfilaria test
After positive immunoassay
Why might you get false negatives in microfilaria concentration techniques
Microfilariae are not present in all heart worm infected dogs (rarely found in cats)
What are 4 techniques for detecting ectoparasites
- Direct visualization/identification
- Skin scarping
- Cellophane tape prep
- Skin histopathology
How can you use direct visualization to identify species of ticks, lice, and mites
Use external characteristics like ornamentation, mouth parts
Short palps and inornate sputum indicate what type of tick
Rhipichephalus
Short palps and ornate sputum indicate what type of tick
Dermacentor
Long palps and inornate scutum indicates what type of tick
Ixodes
Long palps and ornate scutum indicates what type of ticks
Ambylomma
When would you use skin scraping technique
Suspect mite infestation
When is cellophane tape prep used
Typically for trapping/catching mites/lice that are close to surface, can also be used for Oxyurid equi (pinworm) that deposit eggs along anus