Coccidian Flashcards
1
Q
Name 3 species
A
Toxoplasma gondii
Cryptosporidium
Cyclospora
2
Q
Describe the life cycle of Toxoplasma gondii
A
- Oocysts (containing sporozoites) in cat faeces
- Cysts (containing bradyzoites) in tissues
- Pseudocysts (containing tachyzoites) in macrophages
3
Q
What are the routes of infection of Toxoplasma gondii?
A
- Ingestion of oocysts containing sporozoites (through contamination with cat faeces)
- Ingestion of cysts contaning bradyzoites (ingestion of infected meat)
- Infection via tachyzoites from pseudocysts (congenital infection during acute infection, organ transplants, blood transfusion)
4
Q
How does Toxoplasma gondii oocyst appear under microscope?
A
Has 2 sporocysts containing 4 sporozoites each
5
Q
What are the clinical presentations of acute Toxoplasmosis?
A
Lymphadenopathy, fever (PUO), eye lesions (choroiditis, retinitis, uveitis)
6
Q
When does Toxoplasma gondii reactivate?
A
Upon immunosuppresion (organ transplants)
7
Q
What are the congenital infection of toxoplasmosis?
A
- Neonatal illness - jaundice, anaemia
- Encephalitis
- Intracerebral calcification, retinochoroiditis, hydrocephalus with bulging forehead and micropthalmia of left eye: traid of suggestive toxoplasmosis
- Hepatomegaly
- Splenomegaly
- Abortion/stillbirth
8
Q
What is the risk factor for congenital infection of toxoplasmosis?
A
- Increases with gestation age
- Severity decreases with gestation age
9
Q
Describe toxoplasmic encephalitis
how does it arise? spread to organs? how is it detected?
A
- Complication in AIDS patient resulting from immunocompromised state
- Recrudescence of a latent infection
- Multifocal disease
- No spread to other organs
- Progresses to convulsions
- Detected by CT or MRI (ring enhancing lesions on CT)
10
Q
How to diagnose Toxoplasma gondii?
A
- Serodiagnosis (indirect immunofluorescence, enzyme immunoassay)
- Isolation of organism
- PCR
11
Q
How to treat Toxoplasma gondii?
A
- Pryimethamine + Trisulfapyrimidines
- Spiramycin
