Lecture 29 - Coccidia [Parvum] 1

Question 1

what are select characteristics of apicomplexan

Answer 1

• intracellular w/ apical complex
• gliding motility
• alternating life cycle
• “zoites” and “-onts”

Question 2

what are the types of asexual reproduction

Answer 2

1. binary fission
2. multiple fission
3. budding

Question 3

T/F: asexual reproduction creates many organisms quickly and damages host cells

Answer 3

TRUE

Question 4

sporozoite

Answer 4

infective stafe; spore-like

Question 5

merozoite

Answer 5

inside host cell; will start asexual reproduction

Question 6

merogony

Answer 6

merozoite going through asexual replication

Question 7

meront

Answer 7

containing many merozoites

Question 8

sporogony

Answer 8

asexual replication within oocyst resulting in sporozoites

Question 9

gametogony

Answer 9

merozoite develops into gamete

micro = male
macro = female

Question 10

T/F: a zygote in sexual replication becomes on oocyst later in development

Answer 10

TRUE

Question 11

T/F: C. parvum has a high host specificty

Answer 11

FALSE

Question 12

what is the morphology of C. parvum

Answer 12

oocyte with 4 sporozoites

Question 13

T/F: C. parvum is zoonotic

Answer 13

TRUE

Question 14

what is the transmission of C. parvum

Answer 14

direct life cycle (fecal-oral or ingestion of oocyst)

Question 15

describe the invasion technique of C. parvum

Answer 15

invade microvillus border of enterocyte

Question 16

where does sporulation occur

Answer 16

host gut

Question 17

T/F: the oocyst is immediately infectious after sporulation

Answer 17

TRUE

Question 18

describe the dissemination of C. parvum oocyst

Answer 18

1. thin-walled
   autoinfection (excyst within the same host)
   normal immune system = low grade chronic (D+)
   immunocompromised = hyperinfection
2. thick-walled
   exit in host feces (infectious)

Question 19

describe the direct pathogenesis of C. parvum in 3 steps

Answer 19

1. small intestine microvillus atrophy and dysfunction
2. decreased surface area and absorption
3. increased secretory activity

Question 20

describe the indirect damage caused by C. parvum in 2 steps

Answer 20

1. inflammation
2. increased permeability with fluid loss

Question 21

what clinical disease is caused by C. parvum

Answer 21

mild to severe watery diarrhea

Question 22

what signalment is common to C. parvum clinical disease

Answer 22

neonatal calf (1-2 wk/o) with a subacute (2-3day) history of weight loss, emaciation, and dehydration

Question 23

T/F: C. parvum can be severe/lethal in immunodeficient hosts

Answer 23

TRUE

Question 24

what are the differentials for “calf scours” < 21 days old

Answer 24

1. cryptosporidium 7-16 days
2. enterotoxigenic E. coli
3. rotavirus
4. coronavirus
5. salmonella

Question 25

how is C. parvum diagnosed

Answer 25

1. fecal float centrifugation 2. fecal smear with acid fast stain 3. ELISA/PCR

Question 26

T/F: C. parvum is usually self-limiting

Answer 26

TRUE

Question 27

what is the treatment for C. parvum?

Answer 27

fluid replacement therapy with electrolytes and allow milk access

Question 28

what are control mechanisms for C. parvum

Answer 28

1. sanitation and hygiene 2. isolation/separation of sick and young animals 3. ensure adequate colostrum intake 4. extreme temps and disinfectants for oocyte targeting

Question 29

what are the 4 risk factors of C. parvum infection

Answer 29

1. dirty/contaminated environment 2. stress factors 3. housing sick calves with healthy 4. not enough or low-quality colostrum

Question 30

T/F: C. parvum is not zoonotic

Answer 30

FALSE

Question 31

how is C. parvum transmitted

Answer 31

1. human-to-human 2. direct contact with animals 3. contamination of drinking water 4. food-borne

Question 32

T/F: C parvum incidence is common in veterinarians and farmers

Answer 32

TRUE

Question 33

A 12-day-old calf presents with severe scours. what is your treatment plan?

Answer 33

tx: fluid replacement with electrolytes, milk access, monitor for 3 days