Dengue Fever

Dengue Fever

Dengue is a viral infection that can lead to fever (Dengue fever syndrome) and can sometimes result in severe bleeding (Dengue Haemorrhagic Fever) and shock (Dengue Shock Syndrome).

The Aedes mosquito spreads the dengue virus. This mosquito bites humans during daytime and breeds in relatively clean water stored for drinking or washing purposes and in rainwater that collects in various containers (e.g. tyres, bottles, tanks, shallow wells, plastic bottles.)

People of all ages and both sexes who are exposed to mosquito bites can get this disease. Children usually have a milder disease than adults.

There are basically four ways in which a patient – with Dengue presents himself:

1. Mild uncharacteristic fever.

2. “Break-bone” fever characterized by chills, high fever, severe headache, rash spreading from trunk to extremities, muscle and joint pains preventing all movements lasting for nearly 5 days.

3. DHF or Dengue Hemorrhagic Fever abrupt onset, high continuous fever lasting for 2-7 days with bleeding patches under skin, nose bleeding, gum bleeding, blood vomit, black tarry stool, capillary leakage ( ascites and pleural effusion), low platelet count and around 20% rise in haemotocrit.

4. DSS or Dengue Shock Syndrome shows all the signs and symptoms of DHF with cold clammy skin, weak and rapid pulse, hypotension and narrow pulse pressure.

Treatment

There is no specific drug or vaccine available that acts against the Dengue virus. Management follows general principles: –

  • Bed-rest under a mosquito net.
  • Sponge for fever.
  • Paracetamol for pain and fever.

Avoid Asprin and other NSAIDs that can reduce platelet count and increase bleeding

Cheek vital signs, haematocrit, urine output for signs of dehydration and electrolyte imbalance. Rapid intravenous replacement of fluids and electrolytes to sustain patient till recovery occurs. Plasma or plasma colloid preparations should be given if the haematocrit remains elevated. Care should be taken to avoid over hydration and pulmonary oedema (should this occur, diuretics may be used) Benzodiazepines (eg. diazepam) may be given to calm patients. Platelets concentrate needs to be given in those with low platelet count.

The disease cannot be spread by direct contact. It spreads only via Aedes mosquito bite. The transmission route is ‘Man-Mosquito- Man’.

This spread of the disease can be achieved by protecting individuals from mosquito bite (sleeping under a mosquito net, using insect repellants) and by controlling the Aedes mosquito population in the area.

The anti mosquito measures include:

  • Reduce Aedes mosquito breeding ground by getting rid of water holding containers such as discarded tins, empty pots, broken bottles etc.
  • Destroy larvae by adding oil to water collected in small ponds etc.
  • Kill adult mosquitoes by spraying insecticides.

Difference between Dengue Fever complicated by bleeding from DHF

Dengue Fever with Bleeding

  • Bleeding from pre-existing lesion like peptic ulcer.
  • Ascites and Pleural Effusion not seen.
  • Liver usually not enlarged.
  • Haematocrit falls.
  • Leucopaenia (fall of WBC)
  • Mild fall in Platelets count (rarely less than 1,00,000/cumm.

DHF – Dengue Hemorrhagic Fever

  • Bleeding under skin and from all mucosal surfaces.
  • Ascites and pleural effusion seen.
  • Liver enlargement seen in 1-2 days.
  • Haematocrit rises by 20% or more.
  • Leucocytosis (rise in WBC count)
  • Severe fall in Platelets count (usually less than 1,00,000/ cumm.)