232.4 📌 章末速蚘

  • Toxoplasma gondii: apicomplexan, cat = definitive host, intermediate hosts (mammals) + tissue cysts
  • Transmission: undercooked meat (tissue cysts), cat feces oocysts, vertical (1° maternal pregnancy), transfusion/transplant
  • Immunocompetent: 80-90% asymptomatic; symptomatic = mononucleosis-like
  • Congenital: chorioretinitis + hydrocephalus + intracerebral calcifications (Sabin tetrad)
  • HIV encephalitis: multi-ring enhancing MRI brain lesions (CD4 < 100 + IgG+); empirical Tx standard
  • Diagnosis: serology (IgM + IgG + avidity) + PCR + MRI
  • Treatment:
    • Maternal acute: spiramycin (vertical prevention)
    • Fetal infection / newborn / encephalitis / ocular severe: sulfadiazine + pyrimethamine + leucovorin
    • HIV encephalitis: 6 wk + maintenance
    • Newborn congenital: × 1 year
  • Prevention: pregnant women avoid cat litter, undercooked meat, unwashed produce
  • HIV CD4 < 100 + IgG+: TMP-SMX prophylaxis (covers PJP too)
  • Pre-transplant + transplant: serology + prophylaxis
  • PCNSL vs Toxo: multi-ring (Toxo) vs single (PCNSL); EBV PCR + thallium SPECT for differentiation
  • 盧醫垫 hint: å­•å©Š + 接觞 cat + 食材 unsafe → maternal screening + spiramycin if positive; HIV CD4 < 100 + neuro → MRI + empirical Toxo