WHO Dengue Severity Classification
The WHO 2009 dengue classification categorizes patients into three severity groups: dengue without warning signs, dengue with warning signs (requiring close monitoring), and severe dengue (life-threatening).
About
The WHO 2009 dengue classification replaced the previous 1997 WHO classification (dengue fever, dengue hemorrhagic fever, dengue shock syndrome). The new classification is simpler and more clinically relevant. Dengue is defined as fever plus ≥2 of: nausea/vomiting, rash, aches/pains, positive tourniquet test, leukopenia, or any warning sign. Warning signs include: abdominal pain/tenderness, persistent vomiting, fluid accumulation, mucosal bleeding, lethargy/restlessness, liver enlargement >2cm, increasing hematocrit with decreasing platelets. Severe dengue involves severe plasma leakage leading to shock or respiratory distress, severe bleeding, or severe organ impairment (liver AST/ALT ≥1000, impaired consciousness, heart or other organ failure).
Formula
Classification based on: fever + symptoms → warning signs → severe criteria.
Dengue without warning signs: fever and ≥2 symptoms, no warning signs. Dengue with warning signs: fever + warning signs (≥1). Severe dengue: severe plasma leakage (shock, respiratory distress), severe bleeding, or severe organ involvement.
Score Interpretation
Dengue is the fastest-spreading mosquito-borne viral disease, with 390 million infections annually and 96 million clinically apparent cases. Early classification using WHO criteria guides appropriate management and reduces mortality from >20% to <1% with proper fluid management.
No Dengue — 0–0
No evidence of dengue.
Management: Investigate alternative diagnoses.
Dengue without Warning Signs — 1–1
Mild dengue. Self-limiting in most cases.
Management: Adequate oral fluids, acetaminophen for fever (avoid NSAIDs), monitor for warning signs.
Dengue with Warning Signs — 2–2
Requires hospital monitoring.
Management: Hospitalize, monitor vitals/hematocrit/platelets, IV fluids if needed, watch for severe dengue.
Severe Dengue — 3+
Life-threatening. Requires emergency care.
Management: Emergency ICU care, IV fluid resuscitation (colloids), blood transfusion if bleeding, organ support.
Reference Ranges
| Population | Normal Range |
|---|---|
| Patients with suspected dengue infection | Dengue without warning signs / with warning signs / severe dengue |
Tabeeb+ Medical Review Team
Expert tropical medicine review panel.
View medical review board & editorial policy →Example Calculation
A child with fever for 3 days, abdominal pain, vomiting, and petechiae. No bleeding, no shock. Classification: Dengue with warning signs (abdominal pain + vomiting + mucosal bleeding).
Related Conditions
Related Medications
Common Mistakes
Using NSAIDs for fever or pain in suspected dengue.
Acetaminophen (paracetamol) is the recommended antipyretic. NSAIDs increase bleeding risk.
Frequently Asked Questions
What is the critical phase of dengue?
References
- WHO. Dengue: Guidelines for Diagnosis, Treatment, Prevention and Control. 2009.