Protazoa.

- Immunocompetent: mononucleosis-like symptoms, ⊝ heterophile antibody test.- Reactivation in AIDS → brain abscesses usually seen as multiple ring-enhancing lesions on MRI.- Congenital toxoplasmosis: triad of chorioretinitis, hydrocephalus, and intracranial calcifications.

- Transmission: Cysts in meat; oocytes in cat feces; crosses placenta

Diagnosis: Serology, biopsy (tachyzoite)

Treatment: Sulfadiazine + pyrimethamine