Table 2.

2009 World Health Organization (WHO) dengue case definitions*¹⁴

Probable dengue
Live in or travel to dengue endemic area, fever and two of the following:
Nausea, vomiting
Rash
Aches and pains
Tourniquet test positive
Leucopenia
Any “Warning Sign”
Dengue with Warning Signs
Abdominal pain or tenderness
Persistent vomiting
Clinical fluid accumulation
Mucosal bleed
Lethargy, restlessness
Liver enlargement > 2 cm
Laboratory increase in HCT concurrent with rapid decrease in platelet count
Severe dengue (short form)
Severe plasma leakage
Shock (DSS)
Fluid accumulation with respiratory distress
Severe bleeding (as evaluated by clinician)
Severe organ involvement
Liver AST or ALT >/= 1,000
CNS impaired consciousness
Heart and other organs
Severe dengue (long form)
There is evidence of plasma leakage, such as:
High or progressively rising hematocrit;
Pleural effusions or ascites;
Circulatory compromise or shock (tachycardia, cold and clammy extremities, capillary refill time greater than 3 seconds, weak or undetectable pulse, narrow pulse pressure or, in late shock, unrecordable blood pressure).
There is significant bleeding
There is an altered level of consciousness (lethargy or restlessness, coma, convulsions).
There is severe gastrointestinal involvement (persistent vomiting, increasing or intense abdominal pain, jaundice).
There is severe organ impairment (acute liver failure, acute renal failure, encephalopathy or encephalitis, or other unusual manifestations, cardiomyopathy) or other unusual manifestations.

^*HCT = hematocrit; DSS = dengue shock syndrome; AST = aspartate aminotransferase; ALT = alanine aminotransferase; CNS = central nervous system.