WHO case definitions for dengue fever

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)

Reference:

• (1) World Health Organization (WHO) 2012. Handbook for clinical management of dengue
• (2) Centers for Disease Control and Prevention (CDC). Dengue. Clinical descrioption for case definitions