Dengue fever is a mosquito-borne viral disease. The mosquitoes transmitting it are Aedes aegypti and Aedes albopictus .These bite during day time and breed in clean and fresh water and therefore protection from mosquitoes at night by nets and creams cannot prevent dengue. Mainly they breed in (manmade) containers tube, old tyre, cans and drums which contain water. Aedes albopictus can survive in cold weather and therefore people in cold region also can develop dengue. Four serotypes dengue virus can cause disease therefore a previous attack does not confer protection.
Incubation Period : 4-10 days
Illness Features : High fever, orbital pain (eye ball), headache, rashes, joint aches, nausea.
Type of Dengue Fever:
- Dengue fever or break bone fever with no serious complications
- Dengue hemorrhagic fever with bleeding, low platelet and plasma leakage
- Dengue shock syndrome with low blood pressure
Warning signs occur 3-7 days after the first day of symptom when the temperature begins to decrease. Therefore when the temperature begins to drop one must be wary of severe abdominal pain, rapid breathing, bleeding gums, or bleeding elsewhere red spots (PETECHIAE) and severe tiredness.
Because a virus causes the disease, antibiotics are of no use. Supportive treatment is utmost important.
Diagnostic Dengue Test:
NS1 Antigen (Non structural Protein-1 Antigen) Immunoglobulin M( IgM)Immunoglobulin G ( IgG)
Ig M Result
Ig G Result
Low or negative or not tested
Four-fold increase in samples taken 2-4
Low or negative
Too soon after initial exposure for antibodies to develop or symptoms due to another cause
|Ig M Result
||Ig G Result
| Low or negative or not tested
|| Four-fold increase in samples taken 2-4 weeks apart
|Low or negative
||Too soon after initial exposure for antibodies to develop or symptoms due to another cause
NS1 Antigen is detected within 1 to 2 days following infection and upto 9 days following symptom. NS1 in secondary dengue is detected only during 1-4 days following symptoms.
Test for Management:
Haematocrit (utmost important), Platelet Count: Normal Range 1.5 to 4.0 Lakhs,Liver function test, Ultrasound abdomen if indicated as decided by the treating doctor
When Admission is Needed:
1. Persistent vomiting, Dehydration, Abdominal tenderness, Hepatomegaly, Ascites , Oedema, Mucosal bleed, Respiratory distress, Pleural effusion, Hypotension/shock& Oliguria.
2. Rising Haematocrit > 60%
3. Dropping trend of Platelets to < 50000 Cell Count
4. Comorbid Conditions: Heart disease, Bronchial Asthma, DM, HTN, Peptic Ulcer, Haemolytic anaemia, Pregnancy, Infancy, Old age, Living alone, Far away from hospital
Persons with good urine output taking good amount of oral fluid without any abdominal pain, without breathlessness, Normal BP, without rapid heart rate, with platelet above 01 Lakh will most likely not require admission. Family member are requested to consult the treating doctor.
Indications for Platelet Transfusion:
- 1. For Adults: a) <50000 in the presence of bleeding; b) <10000 even if there is no bleeding
- 2. Prolonged shock with coagulopathy and prolonged PT, APTT (Lab Tests)
- 3. Systemic massive bleeding. In this circumstance blood and platelet maybe indicated which will be decided by the attending physician.
The public must not pressurize the doctors to hospitalize patients whose illness can be better managed at home. Also platelet transfusion must be done only after diagnostic conclusions and in consultation with a physician to avoid undue complication.