232.3 🩺 內科專科考前版

232.3.0.1 1⃣ HIV Toxoplasma Encephalitis vs PCNSL

Feature Toxoplasma PCNSL
Lesion number Multiple (most) Single (most)
Lesion appearance Ring-enhancing Homogeneous enhancing
EBV PCR CSF Negative Positive
Thallium SPECT No uptake Uptake
FDG-PET Reduced uptake Increased uptake
Empirical Tx response Yes 1-2 wk No
Biopsy if needed Atypical or refractory Definitive

232.3.0.2 2⃣ Empirical Treatment Strategy

  • HIV + CD4 < 100 + MRI ring lesions + Toxo IgG+ → empirical Toxo Tx
  • 1-2 wk reassessment
  • If clinical / radiographic improvement → continue (likely Toxo)
  • If no improvement → brain biopsy (consider PCNSL)
  • Biopsy from start if atypical features

232.3.0.3 3⃣ Maternal Screening Programs

  • France: universal monthly seroconversion screening
  • Italy, Austria, Portugal: routine
  • USA: not universal; selective + symptomatic
  • WHO: not universal but consider in endemic
  • Detection + spiramycin for primary infection during pregnancy

232.3.0.4 4⃣ Congenital Toxoplasmosis Long-term Follow

  • Ophthalmology screening lifelong (chorioretinitis reactivates)
  • Audiology
  • Developmental
  • Neurology
  • Multi-disciplinary team

232.3.0.5 5⃣ Atypical Strains + Immunocompetent Severe

  • South American + Tropical strains (TgCMI, TgCM2, others)
  • Cause severe disease in immunocompetent (pneumonitis, retinal disease, severe mononucleosis)
  • Outbreaks linked to specific source (water, soil)
  • Increasing recognition

232.3.0.6 6⃣ Ocular Toxoplasmosis Reactivation

  • Often years-decades after congenital infection
  • May be silent (one eye) or symptomatic
  • Lifelong ophth surveillance for congenital cases
  • Treatment of reactivation reduces visual sequelae

232.3.0.7 7⃣ Transplant + Toxoplasma

  • Donor-recipient transmission (D+/R-)
  • Cardiac transplant especially (Toxo cysts in heart muscle)
  • TMP-SMX prophylaxis post-transplant
  • Monitoring + treatment if reactivation

232.3.0.8 8⃣ 健保 / Taiwan

  • 公費 / 健保 maternal Toxo screening (in some hospitals)
  • 健保 sulfadiazine + pyrimethamine + leucovorin + spiramycin for confirmed
  • HIV TMP-SMX prophylaxis routine

232.3.0.9 9⃣ Recent Outbreaks

  • 2024-2025 reports: highly virulent S American strains
  • Water contamination outbreaks (rare but ongoing)
  • Recreational water concerns

232.3.0.10 10. Future + Vaccines

  • Vaccine in research (animal models, clinical trials uncertain)
  • Veterinary vaccine for cats (limits oocyst shedding) — not widely deployed
  • Detection improvements (PCR + serology combinations)