Coccidian Parasites Flashcards
Coccidian Parasites includes
Toxoplasma gondii
Isospora
Cryptosporidium
Cyclospora
Sarcocystis
Definitive and intermediate host in case of Toxoplasma gondii
Definitive - Cats (oocyst/Sexual reproduction)
Intermediate - Humans
Infective forms in case of Toxoplasma gondii infection
Sporulated oocyst
Tachyzoites
Bradyzoites
Mode of Transmission in case of Toxoplasma gondii
1) Ingestion - Sporulated cyst via contaminated food/water, Bradyzoites via contaminated undercooked meat
2) Blood transfusion - Tachyzoites (actively multiplying)
Congenital Toxoplasmosis is more severe in which trimester
1st trimester
Congenital Toxoplasmosis is more commonly transmitted in which trimester
3rd Trimester
Congenital Toxoplasmosis Clinical features
3C2M
Chorioretinitis
Cerebral calcification - Parenchymal
Convulsions
Microcephaly, Hydrocephalus
Mental retardation
Adult Toxoplasmosis C/F in immunocompetent pt.
Mostly asymptomatic
Painless Cervical Lymphadenopathy
Adult Toxoplasmosis C/F in Immunocompromised pt - HIV +ve
Encephalitis
M/C brain stem involvement
Adult Toxoplasmosis C/F in case of Bone marrow transplantation
Features of pneumonia
On CXR - Bilateral ground glass opacities
IgM + and IgG - Interpretation in case of Toxoplasmosis
Acute infection
IgM + , IgG + (low avidity) interpretation in case of Toxoplasmosis
Acute infection
IgM +, IgG + (Strong avidity) interpretation in case of Toxoplasmosis
Chronic infection
IgM -, IgG + interpretation in case of Toxoplasmosis
Remote infection
IgM -, IgG - interpretation in case of Toxoplasmosis
No infection
Toxoplasma gondi can be grown on
Intraperitoneal injection (mice) can grow
Non cultivable on cell free media
Gold standard method in case of Toxoplasmosis infection
Sabin Feldman test - type of Complement fixation test
Sabin Feldman test procedure
Patient serum (Ab +) + Tachyzoites - Activates complement system + add methylene blue - Tachyzoites distorted
If Ab + Colorless
If Ab - Color present
Treatment of Toxoplasmosis
Pyrimethamine (+ Folinic acid) + Sulfadizine
Organisms causing diarrhea in immunocompromised hosts
Cryptosporidium
Isospora
Cyclospora
Which Coccidian parasites can cause autoinfection
Cryptosporidium
Infective form in Cryptosporidium infection
Sporulated oocysts
Sporozoites in case of Cryptosporidium attaches to
Brush border epithelium (Parasito-phorous vacuoles)
Difference in life cycle of Cryptosporidium and Isospora, Cyclospora
In case of Isospora and Cyclospora
- No parasito phorous vacuoles
- released unsporulated oocyst (No autoinfection)
