219.2 📚 國考版

219.2.0.1 必背 — Virology + Serotypes

• ssRNA flavivirus
• 4 serotypes: DENV-1, 2, 3, 4
• Each homologous lifelong immunity
• Heterologous immunity transient (months) → ADE risk on different serotype

219.2.0.2 必背 — Vector

• Aedes aegypti primary (daytime biter, peridomestic)
• Aedes albopictus secondary (also chikungunya, Zika)

219.2.0.3 必背 — ADE (Antibody-Dependent Enhancement)

• Sub-neutralizing Ab from prior infection
• Binds different serotype
• Increased entry via Fc receptor → severe dengue

219.2.0.4 必背 — Clinical Phases

• Febrile (days 1-3): high fever, retro-orbital + bone pain, rash
• Critical (days 4-7): plasma leakage may occur (around defervescence)
• Recovery (days 7-10): fluid reabsorption, itchy rash

219.2.0.5 必背 — Warning Signs

1. Abdominal pain
2. Persistent vomiting
3. Plasma leakage signs
4. Mucosal bleeding
5. Lethargy
6. Hepatomegaly
7. ↑ Hct + ↓ platelets

219.2.0.6 必背 — Severe Dengue Categories

1. Severe plasma leakage (DSS)
2. Severe bleeding
3. Severe organ involvement

219.2.0.7 必背 — Diagnosis

• NS1 antigen first 5-7 days
• PCR acute
• IgM after day 3-5
• Paired IgG for confirmation

219.2.0.8 必背 — Treatment

• Supportive (no antiviral)
• Fluid management key
• NO NSAIDs / aspirin
• NO routine steroid
• ICU for severe dengue

219.2.0.9 必背 — Vaccines

• Dengvaxia (Sanofi 2015): seropositive 9-45 yr only (screening required)
• Qdenga (Takeda 2022): broader use 4-60 yr, regardless of prior infection
• 預防 mosquito control + DEET

219.2.0.10 必背 — Dengue Mimickers

• Chikungunya, Zika, leptospirosis, malaria, HEV, typhoid, severe COVID-19

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