Cryptosporidium spp. (1)

Question 1

What are the hosts?

Answer 1

Wide range of vertebrates

Cross infection among host species occurs

C. hominis - humans

C. parvum - Cattle (can infect humans)

C. andersoni - Cattle (weaned cattle - abomasum)

Question 2

How do you identify?

Answer 2

Oocysts

 - 4-8 micro m
 - Colorless 
 - Transparent
 - Small 
 - Contains 4 sporozoites 

Similar to other coccidian except:

 - Small and at the microvillar surface of epithelial cells
 - Neonatal or young animals

Question 3

Explain the life cycle

Answer 3

Transmission direct

Sporulated Oocysts - infective
- Passed in feces

Autoinfection occurs

Chronicity of certain cases of immune sufficient hosts

Lethal hyperinfection in immune deficient hosts

Ingestion or inhalation of Sporulated Oocysts, sporozoites are released

Infect epithelium of digestive or respiratory tracts

3 asexual and sexual stages

 - Sporulation
 - Infection and Schizogony 
 - Gametogony and oocyst formation

Unique distinguishing characteristics

 - Small
 - Located at the microvillar surface of epithelial cells

Found in neonatal or young animals

Question 4

What are the sites of infection?

Answer 4

Epithelial cells of digestive and respiratory tracts

Question 5

Describe the Pathogenesis

Answer 5

Clinical signs unapparent

Diarrhea

Immunocompromised patients may develop a life-threatening hyper infective form

Question 6

How do you diagnose?

Answer 6

Oocysts in fecal slides: direct smear with stain or concentrated sugar
flotation
- Oocysts are difficult to see on fecal slides

Staining of slides
- Acid fast stains such as Zichl-Neelsen stains parasite red

IFA

Concentrated sugar solution is the medium

ELISA antigens

Question 7

How do you treat and prevent?

Answer 7

No effective treatment

Supportive therapy

Water filter prevents transmission
- Use filters with 4 micro m aperture

Sanitation

Question 8

What is important about Cryptosporidium spp.?

Answer 8

It is ZOONOTIC