Dengue remains one of the most common causes of acute febrile illness in India. With case counts rising annually and dengue presenting earlier and more severely in repeat infections, every Indian doctor seeing fever patients needs a current, practical protocol. This guide covers NS1 testing, clinical warning signs, fluid management, platelet decisions, and when to admit or discharge. Practical Dengue OPD Protocol for Indian Doctors (2026) 1. Triage at First Contact Confirm day of illness (from first fever day). Check for warning signs and shock immediately. Ask about: prior dengue, pregnancy, comorbidities (DM, CKD, heart disease), distance from hospital. Classify: Group A: No warning signs, tolerating oral fluids, stable vitals. Group B: Any WHO warning sign, but no shock/severe organ failure. Group C: Shock, severe bleeding, or severe organ impairment (ICU). 2. What Tests to Order and When At first visit (any suspected dengue): CBC with differential (platelets, haematocrit, WBC). NS1 antigen: Best on days 1–5. Sensitivity drops after day 5. IgM/IgG ELISA: IgM rises from day 4–5; useful for late-presenting cases. IgG indicates prior exposure. RT-PCR: Most sensitive in first 5 days; reserve for atypical presentations or confirmatory purposes. A negative NS1 on day 1–2 does not exclude dengue — repeat CBC and NS1 if fever persists. Serial Monitoring: Frequency of CBC Group A (outpatient): Daily CBC; review in OPD every 24 h until afebrile 48 h and platelet trend is upward. Group B (admitted): CBC every 6–12 hours; haematocrit trend is your most critical parameter. 3. WHO Warning Signs (Admit All of These) Abdominal pain or tenderness. Persistent vomiting (unable to tolerate oral fluids). Clinical fluid accumulation: ascites, pleural effusion, oedema. Mucosal bleeding (gum bleed, epistaxis, haematemesis, melena). Lethargy, restlessness, or altered sensorium. Liver enlargement > 2 cm. Rising haematocrit with rapid platelet drop. This combination is the key haematological warning sign. 4. Fluid Management Outpatient (Group A): Encourage oral fluid intake ≥2–3 litres/day (ORS, coconut water, glucose water, soups). Avoid plain water in excess. IV fluids (Group B, admitted): Normal saline or Ringer's lactate at 5–7 mL/kg/hour; titrate to urine output 0.5–1 mL/kg/h, stable vitals, and falling haematocrit. Avoid: Aggressive IV fluids in a patient with normalised haematocrit — will cause fluid overload and pulmonary oedema in the recovery phase. 5. Platelet Transfusion: When Is It Actually Needed? Do NOT transfuse platelets prophylactically just because count is falling. Transfuse if: Platelet < 10,000 µL without bleeding, OR < 20,000 µL with active bleeding or before invasive procedure. Platelets typically recover within 24–48 hours of defervescence; over-transfusion increases thrombosis risk. 6. Discharge Criteria (Group A/B Once Stable) Afebrile for ≥48 hours without antipyretics. Improvement in clinical status (appetite returning, alert, no abdominal pain). No warning signs on last assessment. Haematocrit stable; platelets ≥50,000 µL with upward trend. Adequate urine output; tolerating oral fluids and diet. 7. Drugs to Avoid in Dengue NSAIDs (ibuprofen, diclofenac, aspirin): Increase bleeding risk; avoid completely. Paracetamol: Safe and first-choice antipyretic; max 4 g/day in adults. Corticosteroids: No evidence of benefit; may worsen outcomes. Antibiotics: Not indicated unless secondary bacterial infection is confirmed.