206.2 📚 國考版

206.2.0.1 必背 — Types

• Flu A: H1N1, H3N2 (seasonal), pandemic potential via reassortment
• Flu B: Victoria only (Yamagata extinct post-COVID)

206.2.0.2 必背 — Antigenic Variation

• Drift: point mutations → annual variation
• Shift: reassortment → pandemic (only Flu A)

206.2.0.3 必背 — Clinical

• Fever ≥ 39 + headache + myalgia + fatigue + cough
• Abrupt onset, “knocks flat”
• 5-7d duration

206.2.0.4 必背 — High-Risk Groups

• ≥ 65 yr
• < 2 yr
• Pregnant
• Chronic cardiopulmonary/DM/CKD/immunocompromise
• BMI ≥ 40

206.2.0.5 必背 — Complications

• Primary viral pneumonia (ARDS)
• Secondary bacterial (S. pneumo, S. aureus PVL+ necrotizing, GAS)
• Myocarditis, MI
• Encephalopathy (IAE pediatric)
• Myositis, rhabdomyolysis
• No aspirin in children (Reye’s)

206.2.0.6 必背 — Treatment

• Oseltamivir 75 bid × 5d — within 48 hr onset
• Baloxavir single dose alternative
• Hospitalized: start empirical immediately
• Pregnancy: oseltamivir safe + recommended

206.2.0.7 必背 — Vaccines

• Universal ≥ 6 mo annual
• 2024-2025 trivalent (Yamagata dropped)
• IIV3, RIV, LAIV (nasal, 2-49 yr), High-dose / Adjuvanted for ≥ 65

206.2.0.8 必背 — H5N1 2024

• USA dairy cattle outbreak
• Farmworker mild cases
• First USA death Jan 2025
• Pandemic preparedness alert

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