Capillarids, Trichinella, Trichurids Flashcards Preview

Parasitology > Capillarids, Trichinella, Trichurids > Flashcards

Flashcards in Capillarids, Trichinella, Trichurids Deck (55)
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1
Q

Classification

A
Order: Enoplida
Superfamily: Trichinelloidea (Stichosome esophagus)
- Trichuris (whipworm)
- Capillarids (urinary,airway,GI)
- Trichinella spiralis (intestines)
Superfamily: Dioctophymatoidea
- Dioctophyme renale (giant kidney worm)
2
Q

Trichinelloidea - general characteristics

A
  • all lay eggs with 2 polar plugs
  • stichosome esophagus
  • tube surrounded by stichocytes arranged single file down length of tube
3
Q

Which Trichinelloidea spp is larviparous?

A

Trichinella spp

- females do not have polar plugs

4
Q

Trichuris spp. PPP varies with ______

A

Species: swine, canids, ruminants, felids, humans

5
Q

Trichuris spp - life cycle

A

Eggs passed in feces –> L1 develops in egg, does not hatch –> L1 in egg ingested –> hatches in SI –> migrates to mucosal glands of cecum –> L1, L2, L3, immature adult –> immature adults return to lumen of cecum –> adults attach to mucosa

6
Q

Trichuris suis - pathogenesis and clinical sign

A

Adult trichurids - hematophagous

  • diarreha
  • dehydration
  • anemia
  • weight loss
  • catarrhal enteritis
  • mucosal necrosis
  • hemorrhage
7
Q

Trichuris spp. - clinical signs

A
Ruminants
- usually subclinical 
- inappetence
- bloody diarrhea
Cats: rare and asymptomatic
8
Q

Trichuris vulpis - life cycle

A

Unembryonated eggs pass in feces –> L1 devleops in egg, infective eggs remain viable for years –> DH ingests L1 in egg –> hatch in SI (2-10 days) –> migrate to cecum –> Li-L3 in cecum –> penetrate to mucosa –> mature to adults in lumen of cecum –> adults attach to mucosa –> female can produce 2000 eggs/day

9
Q

Trichuris vulpis - clinical signs

A
  • mild: asymptomatic, subclinical
  • severe: hemorrhagic typhlitis or colitis, diarrhea with mucus and fresh blood
  • rarely: bloody diarrhea, weight loss, dehydration, anemia, and death
10
Q

Trichuris vulpis - pathology

A

Developing larvae
- mucosa of SI, no disease associated!!
Adults
- primarily in cecum, thread anterior ends thru superficial mucosa
- large posterior end extends into cecal lumen
- consume blood, tissue fluids, mucosal epithelium = bloody diarrhea, weight loss, dehydration

11
Q

Trichuris spp. - diagnosis

A
  • fecal float: eggs are double pored/plugged, must differentiate from capillarid egg
  • adult: necropsy, whip like
12
Q

Trichuris spp - treatment

A

Numerous approved anthelmintics!!

  • fenbendazole
  • milbemycin oxime
  • febantel
  • moxidectin
13
Q

Trichuris spp. - control

A

Management

  • maintain clean, dry environment
  • kennels: remove feces daily, thoroughly clean all areas at least twice a month
14
Q

Small animal capillarids

A
  • Eucoleus aerophilus: epithelium of trachea, bronchioles (cats, dogs, carniovores)
  • Eucoleus boehmi: muosa of nasal turbinates, or frontal/paranasal sinuses (canids)
  • Aonchotheca putorii: stomach (cats, dogs)
  • Pearsonema plica: urinary bladder mucosa (cat, dog)
  • Pearsonema felis-cati: urinary bladder mucosa or free in bladder (cats)
15
Q

Eucoleus aerophilus - hosts

A

DH: parasite of respiratory tract of fox

  • reported from dog, cat, other carnivores
  • foxes serve as reservoir for infections in domestic animals
  • distribution: NA, SA, Europe
16
Q

Eucoleus aerophilus - life cycle

A

Eggs in sputum or feces –> embryonate in 30-50 days –> L1 from ingested eggs hatch in SI –> penetrate mucosa –> adult inhabit bronchiole, bronchi, trachea, threaded thru epithelial surface –> tracheal mucus, saliva –> migrate by bloodstream to lungs –> L1 penetrate alveoli, migrate up air passages as they develop (L2-L4) –> adults inhabit epithelium of bronchioles, bronchi, trachea –> thin bodies threaded thru epithelial surface

17
Q

Eucoleus aerophilus - clinical signs

A

Often light, inapparent infection

  • slight cough, wheezing, nasal discharge
  • secondary bacterial infections
  • possibly severe in foxes: tracheitis, bronchitis, pneumonia
18
Q

Eucoleus aerophilus - diagnosis

A

Fecal float for eggs

19
Q

Eucoleus boehmi - clinical signs

A

Epithelium becomes hyperemic and hyperplastic

  • sneezing, rhinitis
  • nasal discharge +/- bloody
20
Q

Eucoleus boehmi - diagnosis

A
  • fecal float
  • nasal discharge
  • looking for eggs*
21
Q

Eucoleus boehmi - life cycle

A

Direct

- adults threaded through nasal sinus mucosa

22
Q

E. aerophilus, boehmi, and Trichuris vulpis egg comparison

A
  • E. aerophilus: multicellular embryo fills egg, net-like pattern or ridges on surface
  • E. boehmi: multicellular embryo does not fill egg, pitted surface
  • T. vulpis: lemon-shaped, contains single cell when passed in feces
23
Q

Aonchotheca putorii - clinical signs

A
  • hyperplastic pyloric gastritis
  • superficial mucosal fibrosis
  • ulceration
  • diagnosis via fecal float
24
Q

Pearsonema plica - clinical signs

A

Usually subclinical

  • hematuria
  • dysuria
  • cystitis
  • diagnosis (eggs): urine sediment, flotation of urine, contaminated feces
25
Q

Pearsonema spp - treatment

A

No approved treatments in dogs and cats

  • off label: fenbendazole and ivermectin
  • requires several doses to eliminate infection
26
Q

Eucoleus spp - treatment

A

Both E. aerophilus and E. boehmi have been successfully treated with ivermectin or fenbendazole

27
Q

Trichinella spp - hosts

A

DH: carnivores, omnivores

  • has to be a meat eater!
  • can cause human disease
28
Q

Trichinella spiralis

A

Swine, carnivores, humans

  • worldwide distribution
  • adults in mucosa of small intestine
  • direct life cycle
29
Q

Which Trichinella spp are found in the US?

A
  • T. nativa
  • T. pseudospiralis
  • T. murelli
30
Q

Trichinellosis - life cycle

A

DH: adult nematodes in intestines (PPP: 5-6 days)
- female nematodes burrow into intestine –> produces larvae (L1) –> bloodstream –> L1 distributed in cysts (nurse cell) throughout muscle of host (especially tongue, diaphragm!!) –> infected muscle is ingested by DH

31
Q

Trichinella spiralis sylvatic cycle

A

Predation

- wild carnivorous/omnivorous mammals and prey species

32
Q

Trichinella spiralis domestic cycle

A

Meat scraps/cannibalism

- prey species (rats) ingested by pigs, dogs, or cats

33
Q

Trichinella spiralis - human infections

A

Undercooked:

  • pork
  • pork products
  • horse meat
  • bear meat
  • walrus meat
34
Q

Trichinellosis

A

Ingestion of undercooked meat containing encysted larvae of Trichinella spp

35
Q

Trichinellosis - pathogenesis

A

Exposure to gastric acid and pepsin:

  • larvae released from the cysts
  • invade small bowel mucosa
  • develop into adults (females larger)
  • live 4 weeks in the bowel
  • after 1 week: females release larvae, larvae migrate to striated muscle
36
Q

Trichinellosis - diagnosis

A

Based on clinical signs

  • serology
  • muscle biopsy
37
Q

Trichinella spiralis - clinical signs

A

No signs in naturally infected swine!!

  • adults in intestine: females burrowing = diarrhea, abdominal pain, fever
  • larvae (L1) in muscles: slow down physically, difficulty breathing if invade diaphragm, neurologic signs if in CNS
38
Q

T. spiralis - clinical signs in humans

A
  • inapparent
  • abdominal pain
  • diarrhea
  • fever
  • myalgia
  • malaise
  • periorbital edema
  • death
39
Q

Trichinella spiralis - pathology

A

Larvae enter myocytes
- encapsulated by host derived membrane, takes 3 months
Cysts calcify over time
- larvae may remain alive for 2 years
Myocarditis
- no gross lesions, nurse cells with larvae histologically

40
Q

Trichinella spiralis - diagnosis

A

Muscle biopsy/squash

  • may be negative even in heavy infections
  • larvae may be at early development
  • inconspicuous
  • identification of nurse cell parasite complex in muscle biopsy/squash
  • squash uses 1-5g muscle pressed between 2 glass slides
  • artificial digestion of muscle, then sedimentation to recover larvae
  • detects 3 larvae/g of muscle!!
41
Q

Trichinella spiralis - human diagnosis

A

Clinical signs, serology, biopsy

  • look for antibodies (ELISA)
  • PCR: detection of Trichinella-specific DNA
  • sensitive/specific for detecting small numbers of larvae in muscle tissue
42
Q

World Organization for Animal Health

A
  • requirements for declaring country or parts free of trichinae in domestic swine
  • guarantees the transparency of animal disease status worldwide
43
Q

Trichinella spiralis - pre slaughter control

A

Reduce risks:

  • exposure to infective rodents in wildlife
  • prevent cannibalism in pig herds
  • illegal to feed raw garbage
44
Q

National Trichinella certification program

A

Farm audits performed by veterinarians!!

  • certify farms as free from Trichinella spiralis infection
  • purpose is to open up trade restrictions
45
Q

Trichinella spp - zoonotic potential

A

Certain wild game have high zoonotic risk since we inspect meat from domestic swine
- some Trichinella are resistant to normal freezing processes (T. nativa, T. britovi)

46
Q

Trichinella spp - post harvest methods for management

A
  • slaughter testing: squash preps, muscle digestion
  • processing techniques: traditional approach for US, heating, curing, freezing (not for T. nativa), irradiating
  • consumer education: larval death in 6 min @ 55C, cook to internal temp of 77 C
47
Q

Dioctophyme renale - hosts

A

DH: mustelids, carnivores, canids, felids (PPP 6 months)
IH: invertebrate (2-3 months) ingests L1-L3
PH: crustaceans, fish, amphibians (L3, infective stage, encyst)

48
Q

Dioctophyme renale - incidental hosts

A
  • other mammals
  • herbivores
  • humans: ingest undercooked PH, public health risk!
  • larvae in subq tissue, sporadic distribution including NA
49
Q

Diocotophyme renale adults are usually located in the -_______

A

Right kidney!

50
Q

Dioctophyme renale infections

A
  • patent infection: found in right kidney pelvis
  • latent infection: free in abdominal cavity
  • pathology: destroy/damage right kidney, enlarged left kidney, pressure necrosis
51
Q

Dioctophyme renale - diagnosis

A

Nematodes in kidney, eggs in urine

  • no specific management implications
  • eggs: thick shelled, brown, barrel shaped, bipolar plugs, heavily pitted surface
52
Q

Dioctophyme renale eggs are shed in ______

A

Urine (sediment)

  • unlarvated eggs
  • larvated eggs ingested by intermediate host
53
Q

Dioctophyme renale - clinical signs

A

None in naturally infected hosts

- unilateral infections: compensation, dysruia, hematuria, lumbar pain, fatal if in both kidneys

54
Q

Dioctophyme renale in humans

A

Not usual DH, does not usually present the way it would in natural DH
- often larvae wind up in subq nodules and do not develop further

55
Q

Dioctophyme renale - treatment and control

A

Most infections are symptomatic

  • treatment is not pursued
  • surgical removal of adult nematodes along with affected kidney or from peritoneal cavity will eliminate infection