231.3 🩺 內科專科考前版

231.3.0.1 1⃣ Chagas in Non-Endemic Countries

  • USA ~ 300,000 chronic infections (immigrants from Latin America)
  • Spain ~ 70,000 (largest non-endemic country)
  • Most undiagnosed
  • Screening immigrant populations + symptomatic patients
  • CDC + state public health priorities

231.3.0.2 2⃣ Pre-Immunosuppression Screening

  • Patients from endemic countries (born or extended residence):
    • Latin American immigrants 18-65 yr from endemic countries (especially Bolivia, Argentina, Brazil, Mexico, others)
    • Pre-organ transplant
    • Pre-anti-TNF (rheumatologic, IBD)
    • Pre-chemotherapy
    • HIV + from endemic regions
  • 2 serology tests
  • Treat if positive before immunosuppression
  • Reduces reactivation risk dramatically

231.3.0.3 3⃣ BENEFIT Trial Lessons

  • Benznidazole vs placebo in established Chagas cardiomyopathy (NEJM 2015)
  • No mortality benefit in advanced chronic CM
  • PCR negativization improved
  • Implication: treat earlier (before CM develops) for benefit

231.3.0.4 4⃣ Chagas Cardiomyopathy Management

  • Same as other DCM/HFrEF (ACEi/ARB, beta-blocker, MRA)
  • Anticoagulation for AF or LV thrombus
  • Pacemaker for advanced conduction disease
  • ICD for sudden death prevention (controversial in early stages)
  • Heart transplant for refractory HF (good outcomes, but Chagas reactivation post-transplant risk)
  • Trypanocidal therapy at presentation if 18-50 yr without advanced disease

231.3.0.5 5⃣ Heart Transplant + Chagas Reactivation

  • Reactivation in 30-60% of transplant recipients with Chagas
  • Pre-transplant: treat chronic Chagas
  • Post-transplant: PCR monitoring + pre-emptive treatment
  • Treatment dramatically reduces reactivation morbidity/mortality

231.3.0.6 6⃣ Maternal + Newborn Treatment

  • Maternal screening in pregnancy
  • Don’t treat during pregnancy (benznidazole + nifurtimox teratogenicity concerns)
  • Treat postpartum
  • Newborn screening + treatment of seropositive infants
  • 90%+ cure rate in newborns
  • Important transmission interruption

231.3.0.7 7⃣ Oral Outbreaks (Açaí etc.)

  • Food / juice contaminated with infected triatomine bug feces
  • Acute oral Chagas more severe (high inoculum)
  • Outbreaks reported (Brazil, Venezuela, Bolivia, Colombia)
  • Public health investigation + treat all affected

231.3.0.8 8⃣ Romaña Sign Recognition

  • Unilateral painless periorbital edema + conjunctivitis + preauricular LAP
  • Pathognomonic for acute Chagas
  • Often missed (transient)
  • Endemic country physicians more likely to recognize

231.3.0.9 9⃣ 健保 / Taiwan

  • 眕芋 endemic; mostly imported (immigrants from Latin America)
  • 通報 mandatory
  • 健保 benznidazole + nifurtimox limited availability
  • Specialty ID consultation

231.3.0.10 10. Future + Vaccines

  • Vaccines in research (subunit, DNA, mRNA candidates)
  • Not near clinical use
  • Drug development: fexinidazole + posaconazole + new targets
  • New chemotherapeutics in trials