Dengue Fever

Basics

Description

  • Dengue fever occurs secondary to dengue viral infection
  • Most prevalent mosquito-borne viral infection
  • Poorly understood immunopathologic response causes dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS)
  • DHF and DSS usually occur in patients with previous exposure to dengue virus
  • Hemorrhagic manifestations occur after defervescence of fever
  • Vascular permeability increases
  • Plasma extravasates into extravascular space, including pleural and abdominal cavities
  • Dengue fever, DHF, and DSS
  • World Health Organization – required criteria for the diagnosis of DHF:
    • Fever
    • Bleeding evidenced by one of the following: Positive tourniquet test, petechiae, ecchymosis, purpura, GI tract bleeding, injection site bleeding
    • Increased vascular permeability and plasma leakage as evidenced by an elevated hematocrit (>20%), decreased hematocrit >20% after volume replacement or pleural effusions, ascites or hypoproteinemia
    • Thrombocytopenia (<100,000/mm3)
  • World Health Organization – required criteria for diagnosis of DSS:
    • All 4 criteria of DHF +
    • Rapid and weak pulse
    • Narrow pulse pressure or hypotension for age
    • Cold, clammy skin
    • Restlessness
  • A vaccine is under development

Etiology

  • Occurs in tropical and subtropical regions: Asia, Africa, Central and South America, and the Caribbean
  • Caused by dengue virus serotypes 1–4. A fifth serotype was identified in 2013
  • Transmitted by mosquitoes: Aedes aegypti and Aedes albopictus
  • Incubation period of 3–14 d
  • There is only transient and poor cross protection among the 4 serotypes
  • Up to 390 million infections occur per year with nearly 100 million resulting in illness

There's more to see -- the rest of this topic is available only to subscribers.