Epidemiology

Etiology

There are 4 dengue virus serotypes, and secondary infection with a different viral serotype is common and is usually associated with more severe illness.

Pathophysiology

Clinical features

• Dengue fever (nonhemorrhagic)
  • Flu-like febrile illness with marked myalgia &/or arthralgia
    • Often referred to as “break-bone fever”
  • Diffuse maculopapular rash
  • Retroorbital pain
  • Leukopenia
• Severe dengue (hemorrhagic, formally called dengue hemorrhagic fever or DHF)
  • DHF typically occurs as a result of an antibody-dependent reaction in patients who are reinfected with a different serotype
  • Generally develops as the initial fever subsides (∼ 1 week after onset)
  • Temperature change: ranges from hypothermia to a second spike in fever
  • Severe hemorrhagic manifestations (e.g., petechiae, ecchymoses, purpura, hematemesis, melena) due to thrombocytopenia (&lt 100,000/mm3)
  • Severely increased vascular permeability
    • Pleural effusion, respiratory distress
    • Ascites, abdominal pain
    • Severe ↑ or ↓ Hct
  • Positive tourniquet test (petechiae after sphygmomanometer cuff inflation for 5 min)
  • Spontaneous bleeding → shock

Diagnostics

Treatment