Apicomplexa pt 3 Flashcards
Sarcocystis general characteristics
Worldwide distribution
- predator is the definitive host
- prey is the intermediate host
- indirect life cycle
Sarcocystis - DH
PPP: 7-14 days
- no merogony
- gametogony
Sarcocystis - IH
Merogony
- no gametogony
Sarcocystis cruzi
DH: dog, wolves, coyotes, raccoons, foxes, hyena
IH: cattle, ox, bison
S. cruzi - infective stages
DH: sarcocyst with bradyzoites
IH (or aberrant host): oocyst, sporocysts
S. cruzi - route of infection
DH: ingestion of tissue cyst (sarcocyst) containing bradyzoites
IH: ingestion of oocysts/sporocysts in environment
S. cruzi - site of infection
DH: intestinal tract
IH: extraintestinal - heart, skeletal muscle, tongue, esophagus, diaphragm
S. cruzi - pathology
DH: asymptomatic, no immunity
IH: acute, anorexia, pyrexia, anemia, abortion in final trimester
S. cruzi IH - diagnosis
- clinical signs
- presence of sarcocyst on histology (1 cm, cylindrical)
- antibody detection
S. cruzi DH - diagnosis
- fecal float: sporocysts/oocysts
- free sporocysts
- oocyst is double the size of the sporocyst
S. cruzi - treatment and control
IH: prophylactic
- predator/prey control
- avoid fecal contamination
- avoid uncooked meat
- bury or incinerate dead livestock
Sarcocystis neurona
DH: opossums
IH: armadillo, raccoon, cat, skunk
Accidental host: horse
–> agent of EPM in US, Canada, Brazil, Panama
S. neurona - infective stages
DH: sarcocyst (with bradyzoites) in an intermediate host
IH: sporocyst, oocysts
Accidental host: sporocyst, oocysts
S. neurona - site of infection
DH: intestine
IH: skeletal muscle, tongue
Accidental host: CNS
S. neurona - clinical signs
DH: none
IH: asymptomatic
Accidental host: neurological
S. neurona - diagnosis
DH: oocyst, sporocyst on fecal float
IH: sarcocyst on histology, IFA, PCR
S. neurona - EPM
Diagnosis - neuro exam - equine CSF, blood tests Problem with diagnostics - organism difficult to detect - rule out: N. hughesi, EHV, lyme disease, west nile, etc Pathology: - lesions on neural tissue
S. neurona - EPM treatment
FDA approved medication (ponazuril, diclazuril, combo sulfadiazine and pyrimethamine
- some vaccines, not efficatious
- relapse common
- protect feed/water source, reduce road kill
EPM increased risk
- summer, spring, fall
- presence of oppossums, wooded area
- horses age (1-5 yrs, and greater than 13 yr)
- stress via transport, injury, parturition
Sarcocystis spp. - other hosts
Waterfowl - S. rileyi
- white breast disease
Sarcocystis - humans
DH: S. hominis, and S. suihominis
Clinical signs: 24 hr post ingestion of pork
- nausea, vomiting, diarrhea
Cryptosporidium
Host: mammals, birds, reptile, fish
Cryptosporidium - infection site
GI
- upper respiratory tract
- bursa/proventriculus of birds
Cryptosporidium ______ life cycle
Direct
- autoinfection can occur!
Cryptosporidium - routes of infection
Fecal-oral
- autoinfection
- contaminated water, feed, aerosol, mechanical transport
Cryptosproidium - PPP
1 week or less
C. parvum
Cattle
- intestinal disease in neonates (1-4 weeks)
- site of infection: ileum
- PPP: 3-6 days
C. parvum - pathology
- diarrhea, depression, anorexia
- loss of epithelial cells
- dehydration
- electrolyte imbalance
- impaired nutrient digestion, absorption
C. andersoni
Mature cattle
- no clinical disease
- chronic subclinical infections
- site of infection: abomasum
C. andersoni - pathology
- dilation of peptic/pyloric glands
- hypertrophy of gastric mucosa
- thinning of epithelium
- impaired protein digestion
C. bovis
Previously mistaken for C. parvum
- common in older calves (weaned)
- no clinical disease
Cryptosporidium canis
Puppies less than 6 months
- asymptomatic shedding in older dogs
- rarely associated with disease
- low prevalence
- diarrhea, weight loss
Cryptosporidium felis
Rarely associated with disease
- diarrhea, anorexia, weight loss
Cryptosporidium - diagnosis
Oocyst detection on sugar float
- modified acid fast
- PCR
- intermittent shedding
Cryptosporidium - oocyst morphology
No sporocyst
- 4 sporozoites (free in oocyst)
- sporulates in host
Cryptosporidium - treatment/control
No efficacious treatments
- fluid and electrolyte therapy
- self-limiting in immune compotent host
- clean up environment
What are the 3 species of cyrptosporidium in avian hosts?
- C. meleagridis (turkey, human)
- C. baileyi (poultry)
- C. galli (finches, chickens)
What are the 3 forms of cryptosporidium in avian hosts?
- intestinal (SI): enteritis, diarrhea, distended SI, mucus, villous atrophy, lesion in proventriculus
- respiratory: rails, coughing, sneezing, dyspnea, “swollen head syndrome”
- renal: pale kidneys, enlarged, fibrotic area
