Cryptosporidium Flashcards
What kind of parasite is cryptosporidium spp?
Apicomplexan protozoan parasite
How many species of cryptosporidium are there?
39 different species some zoonotic
What cryptosporidium species has a low host specificity?
Cryptosporidium parvum
How many hosts does cryptosporidium have?
1- No intermediate host direct
Where does cryptosporidium parasitize?
Parasitizes mucosa
Cryptosporidium is intracellular extracytoplasmic what does this mean?
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
Describe the life cycle of cryptosporidium
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
Describe the pathology of cryptosporidium
Enteritis
Villouse atrophy
Crypt hyperplasia
Loss of mature epithelial cells
When do clinical symptoms of cryptosporidium occur?
3-7 days after infection- coincides with oocyst shedding
What are the clinical signs of cryptosporidium?
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
Why does the animal usually resolve itself after 4-7 days?
Self limiting infection
Stimulates good immunity
How does zoonosis of cryptosporidium often occur?
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
How is cryptosporidium diagnosed?
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
How is cryptosporidium controled?
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
What parasite causes coccidiosis?
Eimeria spp
Very host specific just to let you know
- No worries
How many hosts are involved in Eimeria life cycle?
1- direct life cycle
Describe the Eimeria life cycle
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
What is the difference between cryptosporidum and eimeria spp?
Crypto- does not invade cells, eimeria does
What is the difference between Eimeria and toxoplasma sporulated oocysts?
Eimeria has 4 sporocysts with 2 sporozoites each
Toxoplasma 2 sporocysts containing 4 sporozoites each
What ruminants does eimeria affect?
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
What is infection of Eimeria often associated with?
Poor housing
Poor hygeine
Over-stocking
What ate the clincal signs of eimeria?
Profucse diarrhoea
Dehydration
Weight loss
Damaged intestinal mucosa- Oedamtous, inflamed, possible mucosal haemorrhage
How is Eimeria treated?
Treatment with coccidiocidal drugs- toltrazuril, diclazuril
Strong immunity
Diagnosis- typical clinical findings usually affecting large numbers of animals
How many hosts are involved in sarcocystis life cycle and briefly describe it?
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
What are the hosts involved with sarcocystis capracanis and hiricanis?
Sheep to dog
What species are involved with sarcocystis hirsuta?
Cattle to cat
What are the problems of sarcocystis?
Meat condemnation from cysts
Cattle infected in 3rd trimedter may abort
