Cryptosporidium spp

Question 1

Classification of cryptosporidium spp:

Answer 1

Protozoan
Sporozoan

Question 2

Direct of indirect life cycle?

Hosts:

Answer 2

Direct life cycle

Humans are definitive hosts

Cows are also major hosts of crypto.

Question 3

Explain transmission and life cycle stages:

Answer 3

1. Oocysts are excreted by feces and end up in water.
2. Hosts ingests and excystation occurs.
3. Four sporozoites are released and become trophozoites which parasitize epithelial cells.
4. In these cells trophozoites undergo asexual multiplication (schizogony/merogony) and form merozoites.
5. Merozoites undergo sexual replication (gametogony) and produce microgametes and macrogametes. Macrogametes get fertilized.
6. Two types of oocysts are formed. The thin walles (auto-infection) and the thick walled which are excreted by feces.

Question 4

Incubation:
Pathogenesis:
Intra- or extracellular:
Symptoms

Answer 4

Incubation:
7 days

Pathogenesis:
By trophozoites

Intra- or extracellular:
Both

Symptoms:
Diarrhea and vomiting. Self limiting in the healthy but can cet complicated in the immunocompromised.

Question 5

Where endemic:

Answer 5

Worldwide, but higher rates in developing countries.

Question 6

Diagnosis:

Answer 6

Microscopy
- Detecting oocysts

PCR
- Detecting DNA

Molecular
- Antigen detection in stool samples