Apicomplexa pt 3

Question 1

Sarcocystis general characteristics

Answer 1

Worldwide distribution

• predator is the definitive host
• prey is the intermediate host
• indirect life cycle

Question 2

Sarcocystis - DH

Answer 2

PPP: 7-14 days

• no merogony
• gametogony

Question 3

Sarcocystis - IH

Answer 3

Merogony

- no gametogony

Question 4

Sarcocystis cruzi

Answer 4

DH: dog, wolves, coyotes, raccoons, foxes, hyena
IH: cattle, ox, bison

Question 5

S. cruzi - infective stages

Answer 5

DH: sarcocyst with bradyzoites

IH (or aberrant host): oocyst, sporocysts

Question 6

S. cruzi - route of infection

Answer 6

DH: ingestion of tissue cyst (sarcocyst) containing bradyzoites
IH: ingestion of oocysts/sporocysts in environment

Question 7

S. cruzi - site of infection

Answer 7

DH: intestinal tract
IH: extraintestinal - heart, skeletal muscle, tongue, esophagus, diaphragm

Question 8

S. cruzi - pathology

Answer 8

DH: asymptomatic, no immunity
IH: acute, anorexia, pyrexia, anemia, abortion in final trimester

Question 9

S. cruzi IH - diagnosis

Answer 9

• clinical signs
• presence of sarcocyst on histology (1 cm, cylindrical)
• antibody detection

Question 10

S. cruzi DH - diagnosis

Answer 10

• fecal float: sporocysts/oocysts
• free sporocysts
• oocyst is double the size of the sporocyst

Question 11

S. cruzi - treatment and control

Answer 11

IH: prophylactic

• predator/prey control
• avoid fecal contamination
• avoid uncooked meat
• bury or incinerate dead livestock

Question 12

Sarcocystis neurona

Answer 12

DH: opossums
IH: armadillo, raccoon, cat, skunk
Accidental host: horse
–> agent of EPM in US, Canada, Brazil, Panama

Question 13

S. neurona - infective stages

Answer 13

DH: sarcocyst (with bradyzoites) in an intermediate host
IH: sporocyst, oocysts
Accidental host: sporocyst, oocysts

Question 14

S. neurona - site of infection

Answer 14

DH: intestine
IH: skeletal muscle, tongue
Accidental host: CNS

Question 15

S. neurona - clinical signs

Answer 15

DH: none
IH: asymptomatic
Accidental host: neurological

Question 16

S. neurona - diagnosis

Answer 16

DH: oocyst, sporocyst on fecal float
IH: sarcocyst on histology, IFA, PCR

Question 17

S. neurona - EPM

Answer 17

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

Question 18

S. neurona - EPM treatment

Answer 18

FDA approved medication (ponazuril, diclazuril, combo sulfadiazine and pyrimethamine

• some vaccines, not efficatious
• relapse common
• protect feed/water source, reduce road kill

Question 19

EPM increased risk

Answer 19

• summer, spring, fall
• presence of oppossums, wooded area
• horses age (1-5 yrs, and greater than 13 yr)
• stress via transport, injury, parturition

Question 20

Sarcocystis spp. - other hosts

Answer 20

Waterfowl - S. rileyi

- white breast disease

Question 21

Sarcocystis - humans

Answer 21

DH: S. hominis, and S. suihominis
Clinical signs: 24 hr post ingestion of pork
- nausea, vomiting, diarrhea

Question 22

Cryptosporidium

Answer 22

Host: mammals, birds, reptile, fish

Question 23

Cryptosporidium - infection site

Answer 23

GI

• upper respiratory tract
• bursa/proventriculus of birds

Question 24

Cryptosporidium ______ life cycle

Answer 24

Direct

- autoinfection can occur!

Question 25

Cryptosporidium - routes of infection

Answer 25

Fecal-oral

• autoinfection
• contaminated water, feed, aerosol, mechanical transport

Question 26

Cryptosproidium - PPP

Answer 26

1 week or less

Question 27

C. parvum

Answer 27

Cattle

• intestinal disease in neonates (1-4 weeks)
• site of infection: ileum
• PPP: 3-6 days

Question 28

C. parvum - pathology

Answer 28

• diarrhea, depression, anorexia
• loss of epithelial cells
• dehydration
• electrolyte imbalance
• impaired nutrient digestion, absorption

Question 29

C. andersoni

Answer 29

Mature cattle

• no clinical disease
• chronic subclinical infections
• site of infection: abomasum

Question 30

C. andersoni - pathology

Answer 30

• dilation of peptic/pyloric glands
• hypertrophy of gastric mucosa
• thinning of epithelium
• impaired protein digestion

Question 31

C. bovis

Answer 31

Previously mistaken for C. parvum

• common in older calves (weaned)
• no clinical disease

Question 32

Cryptosporidium canis

Answer 32

Puppies less than 6 months

• asymptomatic shedding in older dogs
• rarely associated with disease
• low prevalence
• diarrhea, weight loss

Question 33

Cryptosporidium felis

Answer 33

Rarely associated with disease

- diarrhea, anorexia, weight loss

Question 34

Cryptosporidium - diagnosis

Answer 34

Oocyst detection on sugar float

• modified acid fast
• PCR
• intermittent shedding

Question 35

Cryptosporidium - oocyst morphology

Answer 35

No sporocyst

• 4 sporozoites (free in oocyst)
• sporulates in host

Question 36

Cryptosporidium - treatment/control

Answer 36

No efficacious treatments

• fluid and electrolyte therapy
• self-limiting in immune compotent host
• clean up environment

Question 37

What are the 3 species of cyrptosporidium in avian hosts?

Answer 37

• C. meleagridis (turkey, human)
• C. baileyi (poultry)
• C. galli (finches, chickens)

Question 38

What are the 3 forms of cryptosporidium in avian hosts?

Answer 38

• 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