PetriKey

Disease

Toxoplasmosis

Cat / undercooked-meat protozoal infection

TOK-so-plaz-MOH-sis

protozoazoonosiscongenitalopportunistictissue-cyst

High-yield clue

Ring-enhancing brain lesions in AIDS and a congenital triad of chorioretinitis, hydrocephalus, and intracranial calcifications are the classic toxoplasmosis clues.

Overview

A protozoal infection by Toxoplasma gondii, studied for latent tissue cysts, reactivation during immunosuppression, and congenital transmission across the placenta.

Classification

  • Protozoal zoonosis syndrome
  • Toxoplasma gondii infection
  • Foodborne and cat-feces exposure
  • Latent bradyzoite tissue cysts

Lab & identification clues

  • Toxoplasma IgG/IgM serology concept
  • Ring-enhancing CNS lesions on imaging vocabulary
  • Bradyzoite tissue cyst vocabulary

Associations

  • Transmission: cat-feces oocysts, undercooked meat, congenital
  • Usually asymptomatic or mono-like in immunocompetent hosts
  • Reactivation encephalitis when CD4 is low (AIDS)
  • Congenital triad vocabulary

Commonly confused with

  • CNS lymphoma
  • CMV (congenital TORCH)
  • Cryptococcal meningitis

Your notes

Original student-study summary. Sources checked: OpenStax Microbiology 2e, NCBI Bookshelf Medical Microbiology, and CDC topic pages where applicable; reviewed 2026-06. Educational only; no diagnosis, treatment, dosing, or specimen-handling guidance.

OpenStax: Microbiology 2e organism classification foundationssourceNCBI Bookshelf: Medical Microbiology organism chapterssourceCDC: CDC disease and public-health topic pagessource