What is Dengue Fever?
Dengue is a viral infection transmitted by the Aedes aegypti mosquito. It is one of the most common and dangerous mosquito-borne diseases in Sri Lanka, especially during and after the rainy seasons (May-June and October-November).
There are 4 serotypes of dengue virus. Infection with one serotype provides lifelong immunity to that serotype but not to the others. A second infection with a different serotype increases the risk of severe dengue.
Phases of Dengue
| Phase | Duration | What Happens |
|---|---|---|
| Febrile Phase | Day 1-3 | High fever, body pain, headache. Virus is multiplying. |
| Critical Phase | Day 3-7 | Fever drops but this is the MOST DANGEROUS phase. Plasma leakage and bleeding can occur. |
| Recovery Phase | Day 7-10 | Fluid is reabsorbed. Appetite returns. Rash may appear. Platelet count rises. |
Symptoms
Common Symptoms
- High fever (39-40°C) lasting 2-7 days
- Severe headache (especially behind the eyes)
- Severe body and joint pain
- Muscle pain
- Nausea and vomiting
- Loss of appetite
- Skin rash (may appear day 3-5)
Danger Signs
- Severe abdominal pain
- Persistent vomiting
- Bleeding (gums, nose, vomit, stools)
- Restlessness or drowsiness
- Cold, clammy skin
- Reduced urine output
- Rapid, weak pulse
Home Management
Care at Home (Under Medical Supervision)
- Paracetamol ONLY for fever: 500mg-1000mg every 6 hours. Do NOT take aspirin, ibuprofen (Brufen), or diclofenac (Voltaren) — they increase bleeding risk.
- Adequate fluids: Drink at least 2-3 liters daily. King coconut water, oral rehydration solution (Jeevani), barley water, soups, and plain water.
- Complete bed rest: Avoid all physical activity.
- Monitor daily FBC: Your doctor will order daily full blood count tests from Day 3 onwards to monitor platelet count and hematocrit.
- Monitor urine output: Should pass urine at least every 6 hours. Dark or reduced urine is a warning sign.
- Watch for warning signs: The critical period is when fever comes down (Day 3-7). Be most vigilant during this time.
Understanding Your Blood Count
| Test | Normal Range | Significance in Dengue |
|---|---|---|
| Platelet count | 150,000 - 400,000 | Drops in dengue. Below 100,000 needs close monitoring. |
| Hematocrit (PCV) | 36-46% | Rising hematocrit indicates plasma leakage — a danger sign. |
| White blood cells | 4,000 - 11,000 | Usually low in dengue. Helps confirm diagnosis. |
Prevention
- Eliminate mosquito breeding sites: Remove stagnant water from flower pots, tires, gutters, coconut shells, and discarded containers
- Use mosquito repellent on exposed skin
- Wear long sleeves and pants during peak mosquito hours (early morning and late afternoon)
- Use mosquito nets or screens on windows
- Keep surroundings clean — participate in community cleanup efforts
When to Seek Immediate Medical Help
Go to a hospital or call us immediately if:
- Severe abdominal pain or tenderness
- Persistent vomiting (3 or more episodes in 24 hours)
- Any bleeding — gums, nose, vomiting blood, black stools
- Restlessness, irritability, or excessive drowsiness
- Cold hands and feet, pale skin
- No urine for more than 6 hours
- Platelet count below 50,000 or rapidly falling
- Rising hematocrit with dropping platelet count
- Feeling worse when fever comes down (this is the critical phase)
Important: This information is for educational purposes only. If you are unsure about your symptoms or they are severe, please consult a doctor. Our doctors are available for home visits and telemedicine consultations.