228.3 🩺 內科專科考前版

228.3.0.1 1⃣ Babesia vs Malaria Differential

Feature Babesia Malaria
Geography USA NE/Midwest, Europe Tropical worldwide
Vector Tick Mosquito
Liver stage No Yes
Multiple rings in 1 RBC Common Uncommon
Pigment (hemozoin) None Yes
Gametocytes None Yes
Maltese cross Pathognomonic Absent
Severity Asplenic + immunocompromise All non-immune

228.3.0.2 2⃣ Asplenic Patient with Tick Exposure

  • Highest risk
  • Pre-immunization counseling + tick avoidance
  • Suspicious febrile illness → immediate workup
  • Lower threshold for hospitalization + treatment
  • Exchange transfusion readiness

228.3.0.3 3⃣ Exchange Transfusion Indications

  • Parasitemia > 10%
  • Severe hemolysis (Hb < 7)
  • AKI
  • Refractory to antibiotic
  • Multi-organ involvement
  • Asplenic + high parasitemia
  • ICU setting; rapid reduction of parasitemia

228.3.0.4 4⃣ Babesia in Pregnancy

  • Acquisition + vertical transmission
  • Severe disease + obstetric complications
  • Quinine 3rd trimester avoided (PROM, abortion risk)
  • Alternative: clindamycin + atovaquone-proguanil

228.3.0.5 5⃣ Immunocompromise Babesia Management

  • Longer treatment (6+ wk minimum)
  • Combination therapy more aggressive
  • Monitor PCR for clearance
  • B-cell depletion (rituximab) — recurrence common, may need maintenance
  • Transplant recipients: reduce immunosuppression cautiously

228.3.0.6 6⃣ Transfusion Transmission

  • USA NE NIH/FDA priority
  • Donor screening expanded 2024
  • Recipients in non-endemic areas can acquire
  • Hospital surveillance

228.3.0.7 7⃣ 健保 / Taiwan

  • 眕芋 endemic; mostly imported
  • 通報 mandatory
  • 健保 atovaquone + azithro + clindamycin + quinine for confirmed
  • Tick-borne disease awareness

228.3.0.8 8⃣ Recent Babesia Research

  • B. duncani severity reports increasing
  • Climate change → Ixodes range expansion
  • New diagnostic + therapeutic targets
  • Vaccine research

228.3.0.9 9⃣ Diagnostic Challenges

  • Microscopy may miss low parasitemia
  • PCR gold standard
  • Always consider in NE USA + asplenic/immunocompromise
  • Tick exposure history essential

228.3.0.10 10. Future

  • Vaccines in research
  • Newer antiparasitics (tafenoquine alternative explored)
  • Better surveillance + tick control