223.2 📚 國考版

223.2.0.1 必背 — Lassa Fever

• ssRNA Arenaviridae
• W Africa endemic (Nigeria, Sierra Leone, Liberia, Guinea)
• Mastomys natalensis (multimammate rat) reservoir
• Transmission: rodent excreta + person-to-person + aerosol + vertical + healthcare
• 80% mild, 20% severe
• Severe: fever + facial edema + pharyngitis + bleeding + organ failure
• SNHL in 30% survivors (often permanent)
• Pregnancy 3rd trimester: 80%+ mortality
• Treatment: ribavirin (early start essential) + supportive
• Vaccines in trials (MVA-LASV, rVSV-Lassa)

223.2.0.2 必背 — LCMV

• House mouse reservoir
• Vertical → congenital LCMV (mimics congenital CMV: microcephaly, hydrocephalus, chorioretinitis, calcifications)
• Transplant transmission = severe multi-organ disease
• Aseptic meningitis postnatally acquired
• Treatment: supportive; ribavirin off-label for severe

223.2.0.3 必背 — S. American Hemorrhagic Fevers

• Junin (Argentine, Calomys musculinus) — Candid #1 vaccine effective
• Machupo (Bolivian)
• Guanarito (Venezuelan)
• Sabia (Brazilian)
• Treatment: ribavirin + supportive

223.2.0.4 必背 — Ribavirin for Arenaviruses

• IV regimen for Lassa
• Early start critical
• Hemolytic anemia (reversible)
• Teratogenic (avoid pregnancy except life-threatening)

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