Morphology: Enveloped, single-stranded positive-sense RNA virus. Family Flaviviridae. **Four serotypes (DENV-1, -2, -3, -4)** — partial cross-immunity → **antibody-dependent enhancement (ADE)** with secondary heterologous infection (worse disease). Transmitted by Aedes aegypti + A. albopictus mosquitoes (also vectors for Zika, chikungunya, yellow fever).
Typical drugs
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Empiric therapy when resistant
No specific antiviral therapy — supportive care only. AVOID NSAIDs and aspirin (bleeding risk); use acetaminophen for fever. IV fluid resuscitation is the cornerstone in severe disease (dengue hemorrhagic fever / dengue shock syndrome).
Resistance notes
N/A — no antiviral therapy.
Pearls
Classic vignette: returning traveler from tropics 3–14 days after return → high fever + severe myalgia + retro-orbital pain + headache + maculopapular rash ("breakbone fever") + thrombocytopenia + leukopenia. Critical phase at defervescence (days 3–7) — plasma leakage → hemorrhagic fever / shock. AVOID NSAIDs / aspirin — increases bleeding. Supportive IV fluid resuscitation is the management; ICU for severe cases. Dengvaxia vaccine (Sanofi) — only for seropositive ≥9 yo (ADE concern in seronegatives); Qdenga (Takeda) newer, broader indication. Co-infection screening: Zika, chikungunya, malaria (share regions / vectors). WHO 2009 classification: dengue without warning signs, dengue with warning signs (abdominal pain, persistent vomiting, fluid accumulation, mucosal bleeding, lethargy, liver enlargement, ↑Hct with ↓plt), severe dengue (severe plasma leak / hemorrhage / organ failure).
References
- WHO Dengue Guidelines for Diagnosis, Treatment, Prevention, and Control (2009)
- CDC Dengue Clinical Care