WHO case definitions for dengue fever

Last reviewed 01/2018

WHO’s case definitions for dengue fever

The 1997 WHO guideline classified dengue into dengue fever (DF), dengue hemorrhagic fever (DHF) (Grades 1 and 2) and dengue shock syndrome (DSS) (DHF Grades 3 and 4).
Several limitations of the 1997 definition led to a new WHO classification in 2009 which classifies dengue according to levels of severity:

  • dengue without warning signs
    • probable dengue
      • live in/travel to dengue endemic area
      • fever and 2 of the following criteria:
        • nausea, vomiting
        • rash
        • aches and pain
        • tourniquet test positive
      • any warning sign
    • laboratory confirmed dengue (important when no sign of plasma leakage)
  • dengue with warning signs - requires strict observation and medical intervention
    • dengue as defined above with any of the following:
      • abdominal pain or tenderness
      • persistent vomiting
      • clinical fluid accumulation (ascites, pleural effusion)
      • mucosal bleeding
      • lethargy, restlessness
      • liver enlargement >2 cm
      • laboratory – increase in HCT concurrent with rapid decrease in platelet count
  • severe dengue - dengue with at least one of the following criteria:
    • severe plasma leakage leading into:
      • shock (DSS)
      • fluid accumulation with respiratory distress
    • severe bleeding – as evaluated by clinician
    • severe organ involvement
      • liver: AST or ALT ≥ 1000
      • CNS: impaired consciousness
      • failure of heart and other organs (1,2)

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