Parasitology Exam 1 2
Terms
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- What are the 5 kingdoms?
-
1. Planta
2. Animalia
3. Protista
4. Monera
5. Fungi - KINGDOM ANIMALIA
- Helminths and Arthropods
- PLATYHELMINTHES
-
trematodes and cestodes
(Helminths) - NEMATHELMINTHES
-
nematodes
(helminths) - ACANTHOCEPHALANS
-
thorney headed worms
(helminths) - ANNELIDS
-
segmented worms
(helminths) - INSECTA
- flies, bots, lice, fleas
- ARACHNIDA
- ticks, mites
- PARASITE
- an organism which lives on (ectoparasite) or in (endoparasite) another living organism at whose expense ir obtains some advantage.
- ERRATIC OR ABERANT PARASITE
- an organism which wanders from its usual site of infection
- FREE-LIVING PARASITE
- an organism which is capable of living in the environment and leading a nonparasitic existance
- DEFINITIVE HOST
- a host that harbors the adult sexual or mature stage of the parasite, usually defined as the final host.
- INTERMEDIATE HOST
- harbors at least one developmental stage of the parasite before transferring it to another host
- TRANSPORT OR PARATENIC HOST
- harbors a stage of the parasite which does not undergo a developmental stage in the host
- RESERVIOR HOST
- a vertebrate host in which a parasite or disease occurs naturally and is a source of infection
- CARRIER HOST
- carry the parasie but do not show signs of illness
- How often should dogs/cats have fecal exams
- every 6 months, but at least once a year
- Proper fecal collection
- less than 24h 1tbsp (tsp needed) refrigerate, sealed platic or glass device.No paper products
- Handling fecal sample in lab
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Keep good records, lab log, label all samples (name, date species)
handle with caution, gloves, clean up immediately
wash hands - GROSS EXAMINATION
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Age of sample,Blood, Color, Consitency
Foreign materials, mucus, parasites - MICROSCOPIC EVALUATION
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10x to scan, 40x for protozoans
scan al fields of view, review edges when done. -
+
++
+++ -
+ few ova seen (rare)
++ btw few & 1/field (few/mod)
+++ 1+/field of view (many) - FLOTATION SOLUTIONS
-
Sodium Nitrate
Zinc Sulfate
Magnesium Sulfate
Saturated sodium chloride
Sugar (sheather's) - NaNO3
-
efficient in floating ova, even nematode.
expensive, crystals & air bubbles, distort ova, float debris. - ZnSO4
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floats proozoan little distortion.
may distort heminths - Sheather's (sugar solution)
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doesn't distort helminths, doesn't crystallize, inexpensive, long shelf life
sticky, slow rise, attract bugs, distor larva and tremaodes - COMMERCIALLY AVAILABLE FECAL DEVICES
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Ovatector
Ovassay Plus
Fecalyzer - DEWORMING PUPPY
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2,4,6,8 weeks
fecal 2-4 times first year - DEWORMING KITTEN
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3,5,7,9 weeks
fecal 2-4 times forst year - ARTIFACTS?
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slide clean? objective lense clean? more than one?
symmetrical? Intestinal system?
nucleus? reflective? Rough or smooth edge - NEMATODE CHARACTERISTICS
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straight complete intestine, epithelial cells, cylindrical, tapered ends, large body cavity
well developed, muscular esophagus, digestive tube and excretory system - How do nematodes move?
- appears as longitudinal waves of contraction
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How many life stages do nematods have?
Which is the infective stage? -
5 life stages
L3 is usually the infective stages - What are the 4 nematode stages?
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1. adult
2. pre-infective
3. infective
4. pre-adult - What are the 4 nematode transitions?
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1. contamination
2. development
3. infection (l3)
4. maturation - Dirofilaria immitis
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Heartworm
K-Animalia
P-nemathelminthes -
Dirofilaria immitis
Microfilaria -
larval stages l1-l5
tapered ant, blunt post
stationary sluggish motion
295-325um straight body -
D. immitis
ADULT -
found in the R and L ventricles and pulmonary arteries
F-14" M-9" -
D. immitis
INTERMEDIATE HOST - mosquito 60+ speciec worldwide
-
D. immitis
DEFINITIVE HOST - dogs (wild canid) cats, ferrets
-
D. immitis
LIFE SPAN -
adult- up to 5 yrs
microfilaria- up to 30 mnth -
D. immitis
L1 -
adults produce l1. Mosquito ingests l1 in bloodstream.
Larva stay in mosquito's midgut 1 day then migrate and develop into l2 -
D. immitis
L2 - Larva 10 days after infection then turn into L3
-
D. immitis
L3 - Infective stage larva 3 days later. Migrate to mouthprts and find host
- D. immitis from mosquito to host
- mosquito inserts probiscis into host, l3 migrate out through mouthparts onto skin in a "hemolytic pool" Mosquito removes probiscis, l3 migrate through hole left.
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D. immitis
L4 - reside in sq tissues and muscles of abdomen and thorax for 2-3 months.
-
D. immitis
L5 -
Juvenile adults
migrate via bldstrm to cranial/caudal venacava through R atria snd lodge w/i the R ventricle and pulm arteries where they mature - How long does the D. immitis life cycle take?
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6 months for dog
8 months for a cat - When are D. immitis microfilaria most susceptible to death by daily preventatives?
- During the L3-L4 molt
- When is are D. immitis microfilaria most susceptible to death by the monthly preventatives?
- From l3 to the termination of L4
- How many D. immitis adults can live in the dogs heart?
- 1 to 250
-
D. immitis
CHRONIC INFECTION -
1. Dead worm arterial thrombosis, pulm hypertension from thrombosis and iflmtn due to myointimal proliferation.
2. Inflammation and lesions of lung lobes - MYOINTIMAL PROLIFERATION
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assoc with chronic D. immitis
cells on vessel walls causing thickening due to irritation from th worms -
D. immitis
MILDER CASES - dyspnea, cough, exercise intolerance, wt.loss, lethargy, poor body condition
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D. immitis
MODERATE CASES - syncope, hemoptysis, abdominal distension, split S2 sound, murmurs, cardiac gallop, jug distension and pulse
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D. immitis
SEVERE CASES - splenomegaly, hepatomegaly, ascites
-
D. immitis
ACUTE INFECTION -
Venacava syndrome, liver failure, collapse, death
3-5yo never on hwp hemoglobinuria.No standard therapy. manually remove wrms through jugular -
D. immitis
DIAGNOSIS - Signs, hx, detect circulating microfilaria, rads (bkwds D)cardiology, granulocytosis, serology
-
D. immitis
ANTIGEN TEST - best test becuase of "occult hw cases" (no L1)because of preventatives that supress or kill L1
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D. immitis
MICROFILARIAL TEST -
1.direct preparation
2.buffy coat
3.millipore filtration
4.modified knotts test - PRE-ADULTICIDE TREATMENT
-
build up system w/ diet vitamins, rid of parasites
cbc/prof
Rad/angiography/ultrasound -
ADULTICIDE TREATMENT
MILD/MODERATE CLINICAL SIGNS - 2 im (lumbodorsal) inj 24hrs apart repeat in 4 months if necessary
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ADULTICIDE TREATMENT
SEVERE CLINICAL SIGNS -
give 1 im inj.
1mnth later give 2 im inj 24 hrs apart - IMMITICIDE
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adulticide treatment arsenic
Melarsomine Dihydrochloride - POST- ADULTICIDE TREATMENT
- Strict confinement. 4-6 weeks, leash walk, quiet calm, poss meds (aspirin), vitamins and dietary instuctions
- MICROFILARICIDE TREATMENT
-
Heartgard, or interceptor
Bovine Ivomec -
D. immitis
RETESTING -
ADULTS 4 mnths post with antigen
MICROFILARIA microfilarial test 1 mnth post - IVERMECTIN, PYRANTEL
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Heartgard, Triheart plus, Iverheart
rounds, hooks - MILBEMYCIN OXIME
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Interceptor
round, hook,whips - DIETHYLCARBAMAZINE CITRATE, OXIBENDAZOLE
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Filaribits plus
rounds, hooks, whips - MOXIDECTIN
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Proheart
inj-hooks - MILBEMYCIN OXIME, LUFENUERON
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Sentinal
rounds, hook, whip, fleas - SELAMECTIN
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Revolution
round, hooks cats
fleas, ticks, earmites, mange -
Dirofilaria immitis
FELINE PATIENT -
need to be exposed to many more L3. L4 can become ectopic
adults live 2yrs smaller 1-9 burden, usually males, 80% of cats occult -
D. immitis
Why are tests less diagnostically significant in cats? -
low worm burden-antigen
cats can spontaneously recover and antibody tests for exposure - What signs can feline D. immitis mimic?
-
1.Paragonimus kellicotti
2.Aelurostrongylus abstrusus
3.feline asthma or bronchitis
4.cardiomyopathy
5.fur balls -
D. immitis FELINE
when are cats most at risk? -
when worms first reach heart (L5)
and when adults first start to die - FELINE HEARTWORM FACTS
-
fewer mosquitoes will feed.
microfilaria only live 1 month, poor reservoir hosts - ARDS
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acute respiratory distress syndrome
HW in fel can cause an intense reaction in lungs resulting in ARDS -
D. immitis FELINE
CARDIAC SIGNS - pulm hypertension R sided heart failure and cardiac signs minimal.
-
D. immitis FELINE
What happens in L5 - 100 days post bite immunologic response causes asthma like symptoms. after adults signs disappear and become intermittent
- PIMS
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Pulm Intravascular Macrophages
cats spec macrophages. envelope and digest materials. - What happens when adult heartworms start to die off in the feline pateint?
- PIMs cause an intense reaction wich irritates the lungs and cause them to stop functioning
-
D. immitis FELINE
CLINICAL SIGNS -
4-7 months post bite int asthma like sign
When worms begin to die
acute death acute signs chronic signs -
D.immitis FELINE
CHRONIC SIGNS - coughing vomiting dyspnea lethargy anorexia wt. loss
-
D. immitis
ACUTE SIGNS - collapse dyspnea convulsions diarrhea/vomiting blindness tachycardia syncope sudden death
- What are the most common signs of D.immitis in the FELINE
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1.vomiting
2.respiratory signs
3.wtloss
4.anorexia - Why vomiting in a cat with D. immitis
- a release of substance by cells which regulate the inflammatory procss in the lungs wich stimulate the area of the brain that can trigger vomiting
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D. immitis FELINE
DIAGNOSTIC TESTS - cbc(nRBC,anemia, basophilia) rads fecal(other par) EKG echocardiography tracheal wash (eos par) arteriogram antibody antigen
-
D. immitis FELINE
ANTIGEN TESTING -
don't detect males or early infections(l6m)low# of fem.
Positive is a defenitive dx of heartworm -
D.immitis FELINE
ANTIBODY TESTING - screening for cats, exposure fails to determine adults
- THIACETARSAMIDE
-
Caparsolate
tx for feline hw
30-50% cats die from sudden death of worms. oxygen cage 2wks hospital -
D.immitis FELINE
CORTICOSTEROID TX - qod for short time watch for signs of dyspnea or cyanosis
- ADULTICIDEIN COMPLICATIONS IN CATS
-
1.pulmoanry edema
2.embolism
3.anorexia
4.sudden death -
D.immitis FELINE
ALTERNATIVE TX -
mechanical removalof adultworms(risky)
put on heartworm preventative (still talk) -
D. immitis FELINE
POST TREATMENT -
antigen test 12wks post adulticide
prevention - FELINE HEARTWORM PREVENTATIVE
-
Heartgard for cats, interceptor for cats(higher dose than dogs)
Revolution - What does ELISA stand for?
- enzyme linked immunosorbent assay
- COMPONENTS OF ELISA
-
1.solid phase or test surface
2.sample
3.conjugate
4.wash solution
5.chromogen - WHOLE BLOOD
- antigoagulant rbc wbc plasma serum
- PLASMA
- fibrinogen
- SERUM
- no fibrinogen
- What is the basic principle of ELISA technology
- when conjugate and chromogen combine, you will ALWAYS get a color change
- CHROMOGEN
- a reagent which changesor produces color when exposed to a catalyst
- CONJUGATE
- an antibody that has been bound or conjugated to an enzyme
- DIROCHECK
-
serum or plasma
refrigerate
15 minutes
single or batch - POSITIVE CONTROL
- tells you that when you ran the test, the reagents contained in the kitwere functioning properly
- NEGATIVE CONRTOL
- tells you that the operator of the test ran the test properly and according to the directions
-
MEMBRANE ELISA KIT
Idexx snap -
less dependent on user technique than microwell
whole blood, plasma, serum
refrigerate
10 minutes - ICT
-
Immunochromatographic Technology
latex and gold staining replace enzyme/chrom - BENEFITS OF ICT TESTS
-
greater test stability=room temp storage
no wash step - COMPONENTS OF ICT TEST
-
solid phase
sample
colloidal gold or latex conjugate
+/- flow solution - FALSE POSITIVE TESTS
-
sample quality
inadequate washing
overincubation
defective test
cross-reaching protein in sample - Toxocara canis
- Large Roundworms of dogs
-
T. canis
OVA - round thick braided outer membrane, large round dark nuclei. infective in 2-4wks in soil. can survive in soil for years
-
T. canis
ADULTS -
spaghetti-like seen in feces f-20cm m-10cm
most puppies are born with them -
T.canis
METHODS OF TRANSMISSION -
1.direct (trachael somatic)
2.transmammary
3.transplacental
4.predation of paratenic - HYPOBIOTIC
- encysted larva that can be reactivated during high stress
-
T.canis
TRACHAEL (HEPATOTRACHAEL) TRANSMISSION - Puppies eggs in soil swallowed by dog hatch in stomach penatrate the intestinal mucosa migrate-liver-lungs-cough-swallow migrate, mature in small intestine 1month
-
T. canis
SOMATIC MIGRATION -
adults eggs swallowed hatch in stomah migrate to tissues.
hypobiotic -
T.canis
TRANSPLACENTAL - hypobiotic larva reactivate during pregnancy. enter puppies in utero during 3rdtri (d42)larva take trachael route pos 3wks
-
T.canis
TRANSMAMMARY - hypobiotic pregnancy lactation shed in milk swallowed tracheal route adults in 2-3wks
-
T.canis
PREDATION OF PARATENIC HOSTS - least common for dogs ingested in soil by phost. larva hatch in stomach somatic route. dog eats rodent(or uncooked meat) larva reactivates and develops in si 3-4wks
-
T. canis
CLINICAL SIGNS - puppies, lack of growth loss of condition dull hair coat, potbelly, vomiting worms, D/C, cough, bacterial pneumonitis, anemia
-
T.canis
DIAGNOSIS -
microscopic id of eggs in feces
gross detection of adult worms in feces or vomitus -
T.canis
CONTROL -
rid area of feces treat all puppies, use 1% chlorox solution to clean
control rodent pop -
T.canis
ZOONOTIC TRANSMISSION -
humans ingest infective eggs
eggs hatch in si can enter blood stream & tissues
can damage or kill hosts infected tissue -
T.canis
ZOONOTIC SIGNIFICANCE - visceral larva migrans, cns neurological ocular larva migrans(blindness)fever, irritability, abdominal pain &hives
-
T.canis
TREATMENT FOR HUMANS WITH OLM & VLM -
diethylcarbamazine
albendazole
mebendazole - Toxocara cati
- Large roundworm of cat
-
T.cati
OVA - ova looks like canis but a bit smaller and more cytoplasm
-
T.cati
ADULTS -
spaghetti-feces f-12cm m-6cm
not passed transplacentally -
T. cati
METHODS OF TRANSMISSION -
1.direct
2.transmammary
3.predatation of paratenic host -
T.cati
DIRECT TRANSMISSION -
same as on dogs.
somatic more common
takes 2 months -
T.cati
TRANSMAMMARY -
same as dog
takes 2 months -
T.cati
PREDATION OF PARATENIC HOST -
by far most common method of transmission in cat
same as dog
takes 2 months -
T.cati
ZOONOSIS - same as dogs
- Toxascaris leonina
- roundworms of dogs and cats
-
T. leonina
OVA -
round/oval large round thin outer mbrn, nucleus does not fill ova
infective in 1wk does not survive in soil as long -
T. leonina
ADULTS -
spaghetti feces f-10cm m-cm
not transmitted transplacentally pr transmammary -
T. leonina
METHODS OF TRANSMISSION -
Direct-ingested si 2-2.5 mnth
predation of paratenic host
2mnths -
T. leonina
DIAGNOSIS TX & CONTROL - same as toxocara
-
T. leonina
ZOONOSIS - not considered zoonotic
- Ancylostoma caninum
- hookworm
-
A. caninum
ADULTS -
avg.10mm (6-20) f-larger
very large buccal cavity
2-3 pair of sharp teeth
common in NE - How many eggs can female Ancylostoma caninum produce?
- 10,000-25,000 eggs/day
-
A. caninum
DEFINITIVE HOST - dogs
- A. tubaeforme
- hooks of cats
- A. braziliense
-
hooks dogs and cats
more pathogenic to humans - Uncinaria stenocephala
-
hooks of dogs and cats
less common and less pathogenic - A. duodenale
- humans in S. Europe, Africa, N. Asia and S. America
- Necator americanus
- humans in southeastern USA
-
Ancylostoma caninum
ADULTS -
attach to si, causes hemorrhages, feed on hosts blood
can have devastating effects on humans - How many humans are infected per year?
- 1 billion
-
A. caninum
LARVAL STAGES -
1. Rhabditiform
2. Filariform - HOOKWORMS IN HUMANS
- penetrate skin or ingested adults in 1wk attach si suck blood
- HOOKWORMS IN HUMANS SIGNS
-
D and cramps itching & rash a site
anemia wt.loss
stunted growth and mental development in heavy infestation - CUTANEOUS LARVA MIGRANS
- a linear toruous erythematous and intensely puritic eruption of the skin usually caused by migration of nematode larvae
-
A. caninum
OVA - oval shaped thin outer membrane clusters w/i ova consitst of 2-8 morula stage cells
-
A.caninum
LIFE CYCLE -
rhabditiform larva hatch within 1-2
molt into filariform larva -
A.caninum
MODES OF TRANSMISSION -
1.ingestion(direct)
2.percutaneous
3.transmammary
4.transplacental -
A.caninum
INGESTION(DIRECT) -
ingest infective filariform larva.develop in si, eggs passed 2wks postingest.
not all mature some invade skeletalmsc or gut wall and arrest -
A. caninum
PERCUTANEOUS INFECTION -
penetrate skin, extensive tissue migration, enter bldtrm-lungs-cough-swallow-si
shed eggs 1 month
some will arrest -
A. caninum
TRANSMAMMARY & TRANSPLACENTAL -
arrested larva can infect puppies in utero 2 weeks prebirth (d49)
can ingest while nursing -
A. caninum
SIGNS - internal bleeding, erythmatous foot pad, anemia protein loss, iron deficiency, anorexia, lethargy, dull hair, tarry stool, pale mm, sudden death
-
A.caninum
CLINICAL FORMS -
1.peracute hook dz(dam to pups)
2.acute hook dz (sudden exp. older pups)
3.chronic(compensated)hook dz(adults)
4.secondary(compensated)hook dz (old dogs) - Trichuris vulpis
- whipworms
- ADULT WHIPWORMS
-
T.campanula & T.serrata(cat)
rare in cats 25-90mm
whip head(fine) stout post
f-produces 2,000 eggs/day -
T. vulpis
OVA -
football/lemon shape
operculum(plug)each end
remain in soil for yrs
very resistant, heavy to float -
Trichuris vulpis
LIFE CYCLE -
eggs infective 9d soil
dog ingest ova-hatch si-cecum devlope to adult
start prod 70-100/d 3mnths -
T. vulpis
SIGNS -
depends on # in si
pups-dehydration, emaciation, anemia, abdmnl pain death.
adults-bite at flanks mucoid bldyD, intermittent D or asymptomatic -
T.vulpis
DIAGNOSIS -
shedding of ova intermittent
difficult to dx
min15minutes for float 4 neg fecals over 4 days - SUGAR FLOATATION
-
3gm feces:15ccsugar solution
stir&strain mix pour in TT
centrifuge 1500rpm/5-10min
coverslip -4min read 10x