Protozoa - coccidia - Cystoisospora & Crytosporidium

Question 1

Lifecycle of cystisospora

Answer 1

Direct and host specific (one feline indirect)

• schizogony and gametogony in the intestinal epithelium. Oocysts passed in faeces and ingested by specific species

Question 2

Diagnosis of cystisospora

Answer 2

Faecal float -> unsporulated oocysts

• schizonts / merozoites in faces

Question 3

Treament of Cystisospora

Answer 3

• supportive care
• sulphonamides for 1-2 weeks
• Toltrazuril for 1-3 days

Question 4

Prevention and control of Cystisospora

Answer 4

• treat all animals
• prevent predation
• beware around whelping/lactation

Question 5

Pathogenesis of Cystisospora

Answer 5

• mostly only mild pathogenesis but can cause diarrhoea
• young animals susceptible but can develop strong immunity afterwards.

Question 6

Controlling cystisospora in piglets

Answer 6

Hygiene, biosecurity

medicate the sow with feed with coccidiostats

Piglet:

• single oral dose of toltazuril at 3-5 days
• Long acting sulphonamide injection at 6 days of age

Question 7

Significance of Crytosporidium

Answer 7

• diarrhoeal disease
• faecal-oral transmission
• waterborne epidemics

zoonosis vs host specificity

Question 8

Forms of Cryprosporidiosis

Answer 8

Intestinal: diahrrhoea, steatorrhea (fatty faeces)

Gastric: Postpandrial regurgitation

Respiratory: mostly birds

Question 9

Most important cattle Cryptosporidia

Answer 9

C. parvum, C. bovis, C. andersoni

Question 10

Major Cryptosporidia of birds

Answer 10

C. meleagridis

C galli

C. baileyi

Question 11

Cryptosporidium lifecycle

Answer 11

Direct - faecal oral

• sporogony occurs within the host
• thick walled oocyst passed in the faeces (resistant to heat/chlorination)
• thin walled oocysts = autoinfection

Question 12

Position of merozoite

Answer 12

Epicellular - intracellular but extracytoplasmic

Question 13

Pathogenesis of Cryptosporidium

Answer 13

Villous atrophy

Epithelial mucosa release cytokines -> increase H20 and Cl-

• get watery diarrhoea (foul smelling) and malabsorption
• young animals susceptible
• older animals become more resistant
• immunocompromised animals can have a chronic disease whichmay be fatal

Question 14

Features of Cryptosporidia

Answer 14

• Neonatal/post weaning diarrhoea (livestock, foals, pigs, pups, kittens)
• poor colostrum intake
• immunocompromised
• major waterborne pathogen
• self limiting diarrhoea

Question 15

Zoonotic Cryptosporidium

Answer 15

C. parvum

Question 16

How zoonosis occurs with C. parvum

Answer 16

• Only in calves less that 4 weeks old
• high intensity of oocyst excretion
• low infective dose

Question 17

Diagnosis of Cryptosporidium

Answer 17

• Zinc or sucrose floats
• small oocytes, immunofluorescence
• smea with Ziehl-Neelsen
• ELISA or immunochromatography
• PCR

Question 18

Treatment of Cryptosporidium

Answer 18

Supportive care - fluids/electrolytes

Hyper-immune bovine colostrum

• Halofuginone?
• Nitazoxanide?

Question 19

Control of Cryptosporidium?

Answer 19

Hygiene (heat 70 degrees - steam, flame gun, ammonia)

• biosecurity/quarantine
• identify and isolate infected animals
• disinfect contaminated surfaces
• boil water prior to consumption (humans)