感染預防

Buzzwords → Dx

Vaccinations

• Pre-splenectomy / pre-HCT (2-4 wk before): PCV20 + PPSV23 + MenACWY + MenB + Hib + influenza.
• Post-HCT vaccination resumption: 6 mo for inactivated (PCV, influenza, dTaP, HPV, Hib); 12 mo for some live not allowed; 24 mo + no immunosuppression × 3 mo for live (MMR, VZV, RZV recombinant).
• Recombinant zoster (Shingrix) — preferred over live VZV vaccine for HCT, severe immunosuppression.
• Annual influenza for all heme-onc pts.
• Eculizumab/ravulizumab users: meningococcal ACWY + B + antibiotic prophylaxis until vaccine response.

Treatment Algorithm

flowchart TD
  A[Plan immunosuppressive therapy] --> B[Risk assessment: regimen + duration + comorbidities]
  B --> C{High-risk for PJP?<br>steroids ≥20 mg ≥4 wk, fludarabine, CAR-T, post-HCT, alemtuzumab}
  C -- yes --> D[TMP/SMX prophylaxis<br>or dapsone (G6PD-test) / atovaquone]
  B --> E{Prolonged neutropenia or post-HCT?}
  E -- yes --> F[Posaconazole or voriconazole<br>+ acyclovir/valacyclovir]
  B --> G{Allo-HCT?}
  G -- yes --> H[Letermovir for CMV ppx (seropositive)<br>+ posaconazole + acyclovir + PJP ppx]
  B --> I{Rituximab / anti-CD20 + HBV+?}
  I -- yes --> J[Entecavir or tenofovir lifelong / ≥12 mo post-rituximab]
  B --> K{Eculizumab / ravulizumab?}
  K -- yes --> L[Meningococcal vaccinations + abx ppx until established]
  B --> M{Splenectomy / functional asplenia?}
  M -- yes --> N[Penicillin V (children <5)<br>+ encapsulated organism vaccines<br>+ aggressive febrile workup]

Pearls / Pitfalls

• TMP/SMX dose-adjust for renal failure; alternative if sulfa allergy: dapsone (G6PD screen!) or atovaquone or pentamidine.
• Letermovir (CMV ppx) is now standard for CMV-seropositive allo-HCT recipients (Marty NEJM 2017) — replaced preemptive ganciclovir-based monitoring in many centers.
• Posaconazole > voriconazole > fluconazole for mold prophylaxis. Posaconazole tablets > suspension (better absorption). Levels for therapeutic monitoring.
• Voriconazole AEs: hepatotoxicity, visual disturbances (photophobia, color changes), QT prolongation, periostitis, fluorosis, skin cancer (squamous cell long-term).
• Echinocandins (caspofungin, micafungin, anidulafungin): yeast + Candida; less mold (no Aspergillus efficacy in some species).
• Antifungal in steroid-treated GVHD: posaconazole until steroid weaned and ANC >1000.
• Rituximab + HBsAg/core+ → fulminant hepatitis — entecavir / tenofovir prophylaxis ≥12 mo after rituximab.
• Live vaccines contraindicated during active immunosuppression: MMR, VZV (use recombinant zoster Shingrix), oral polio, oral typhoid, BCG, yellow fever.
• CAR-T post-infusion: PJP ppx + acyclovir/valacyclovir + IVIG if hypogammaglobulinemia.
• Eculizumab/ravulizumab = meningococcal vaccine + antibiotic prophylaxis (penicillin or ciprofloxacin) until vaccine response established.
• Latent TB screening before alemtuzumab, anti-TNF, prolonged steroids — IGRA preferred.
• Strongyloides screening for endemic-region pts before steroid initiation — fatal hyperinfection if missed.

Cross-references

• Febrile Neutropenia
• Allo-HCT — comprehensive infection ppx
• CAR-T post-infusion ppx
• PNH — meningococcal ppx with eculizumab
• SCD — penicillin + vaccinations
• G6PD before dapsone
• Drug Regimens — TMP/SMX, posaconazole, letermovir

相關題目

• Q-150 — Post-allo-HCT — CMV prophylaxis
• Q-205 — PJP prophylaxis — high-risk regimens
• Q-206 — HBV reactivation prophylaxis
• Q-207 — Antifungal prophylaxis in AML induction

Sources