Cryptosporidium

Question 1

What kind of parasite is cryptosporidium spp?

Answer 1

Apicomplexan protozoan parasite

Question 2

How many species of cryptosporidium are there?

Answer 2

39 different species some zoonotic

Question 3

What cryptosporidium species has a low host specificity?

Answer 3

Cryptosporidium parvum

Question 4

How many hosts does cryptosporidium have?

Answer 4

1- No intermediate host direct

Question 5

Where does cryptosporidium parasitize?

Answer 5

Parasitizes mucosa

Question 6

Cryptosporidium is intracellular extracytoplasmic what does this mean?

Answer 6

It sits on the top of the cell, outside the cytoplasm covered by the outer cell membrane

Found in the microvillus border of epithelial cells linining alimentary and respiratory tracts

Question 7

Describe the life cycle of cryptosporidium

Answer 7

3-4 days

Sporozoites leave oocyst and attach to epithelial cells between microvilli

Microvilli fuse and expand around the parasite- merogony

Parasite enters trophozoite stage

Trophozite to type 1 meront- 4-8 merozoites

Merozoites enter lumen ansd infect new epithelial cells- type 2 merozoites

Merozoites enter lumen to become either microgamont (M) or macrogamont (F)

The gamonts fuse together to form zygote

Zygote develops into oocyst

Zygote can rupture and cause autoinfection of host or pass thorugh into faeces

Question 8

Describe the pathology of cryptosporidium

Answer 8

Enteritis

Villouse atrophy

Crypt hyperplasia

Loss of mature epithelial cells

Question 9

When do clinical symptoms of cryptosporidium occur?

Answer 9

3-7 days after infection- coincides with oocyst shedding

Question 10

What are the clinical signs of cryptosporidium?

Answer 10

Profuse watery diarrhoea in very young calves and lambs

Dehydration

Inappetance

GI discomfort

Can affect puppies and kittens

Due to rapid onset- mortality is not uncommon

Question 11

Why does the animal usually resolve itself after 4-7 days?

Answer 11

Self limiting infection

Stimulates good immunity

Question 12

How does zoonosis of cryptosporidium often occur?

Answer 12

Livestock shed large numbers of oocysts into environment

Survive for years in optimum conditions

Contamination of water via water fun off into reservoirs

Highly resistant to water treatment systems

Question 13

How is cryptosporidium diagnosed?

Answer 13

Oocysts in faeces- very small- stain with Ziehl-Neelsen or Safronin

Oocysts in environmental samples- immunofluorescent essays

Copro-antigen test (dogs)

Clinical signs

Age of calves

Question 14

How is cryptosporidium controled?

Answer 14

Halofuginone licenced in calves not lambs

Control of environemental contamination- faecal-oro transmission, resistant oocysts

Hygiene

• Good biosecurity
• Quarentine new stock for 7 days to check for scouring
• Disinfect between calves
• Keep feeders clean
• Keep clothing clean

Question 15

What parasite causes coccidiosis?

Answer 15

Eimeria spp

Very host specific just to let you know

• No worries

Question 16

How many hosts are involved in Eimeria life cycle?

Answer 16

1- direct life cycle

Question 17

Describe the Eimeria life cycle

Answer 17

Lambs ingest infective sporocyte- releases sporozoites which invade gut cell and develop and multiply asexually to produce merozoites

First generation of merozoites released and invade neighboring cells

Parts of gut wall packed with parasited differentiate into male and female- gametes- male fertalizes female to form oocyst which is shed

Under correct conditions oocyst sporulates and becomes infective, can take 1 week to 1 year

Sporolated oocys contains 4 sporocysts with 2 sporozoites each

Question 18

What is the difference between cryptosporidum and eimeria spp?

Answer 18

Crypto- does not invade cells, eimeria does

Question 19

What is the difference between Eimeria and toxoplasma sporulated oocysts?

Answer 19

Eimeria has 4 sporocysts with 2 sporozoites each

Toxoplasma 2 sporocysts containing 4 sporozoites each

Question 20

What ruminants does eimeria affect?

Answer 20

Affects calves and lambs

Lambs 4-8 weeks

Housed dairy calves- 3-4 week after weaning

Beef cattle- spring born calves from natural water supplies

Question 21

What is infection of Eimeria often associated with?

Answer 21

Poor housing

Poor hygeine

Over-stocking

Question 22

What ate the clincal signs of eimeria?

Answer 22

Profucse diarrhoea

Dehydration

Weight loss

Damaged intestinal mucosa- Oedamtous, inflamed, possible mucosal haemorrhage

Question 23

How is Eimeria treated?

Answer 23

Treatment with coccidiocidal drugs- toltrazuril, diclazuril

Strong immunity

Diagnosis- typical clinical findings usually affecting large numbers of animals

Question 24

How many hosts are involved in sarcocystis life cycle and briefly describe it?

Answer 24

Two host life cycle- prey- predator

Prey- asexual repro and muscle cyst development (sacrocyst)

Final predator host- intestinal sexual reproduciton and production of mature oocysts

Question 25

What are the hosts involved with sarcocystis capracanis and hiricanis?

Answer 25

Sheep to dog

Question 26

What species are involved with sarcocystis hirsuta?

Answer 26

Cattle to cat

Question 27

What are the problems of sarcocystis?

Answer 27

Meat condemnation from cysts

Cattle infected in 3rd trimedter may abort