Dengue Infections

Dengue fever is an acute illness characterized by fever, myalgia, arthralgia and rash. Severe dengue infection is characterized by abnormalities in hemostasis and by marked leakage of plasma from the capillaries; the latter may lead to shock (dengue shock syndrome).


Dengue fever is caused by infection due to any of the four serotypes of dengue viruses. Dengue viruses are arboviruses that belong to the family Flaviviridae.

The envelop protein bears epitopes that are unique to the serotypes


Dengue viruses are transmitted to humans through the bites of infected female Aedes mosquitoes. Mosquitoes generally acquire the virus while feeding on the blood of an infected person. After incubation for 8-10 days, an infected mosquito is capable, during probing and blood feeding, of transmitting the virus, to susceptible individuals for the rest of its life.


  • Fever — 104 F degrees
  • Headache
  • Muscle, bone and joint pain
  • Nausea
  • Vomiting
  • Pain behind the eyes
  • Swollen glands
  • Rash

Signs and symptoms of dengue hemorrhagic fever or dengue shock syndrome

  • Fever — 104 F degrees
  • Headache
  • Muscle, bone and joint pain
  • Severe abdominal pain
  • Persistent vomiting
  • Bleeding from your gums or nose
  • Blood in your urine, stools or vomit
  • Bleeding under the skin, which might look like bruising
  • Difficult or rapid breathing
  • Cold or clammy skin (shock)
  • Fatigue
  • Irritability or restlessness


If severe, dengue fever can damage the lungs, liver or heart. Blood pressure can drop to dangerous levels, causing shock and, in some cases, death.


Remove sources of standing water

Wear protective clothing. When you go into mosquito-infested areas, wear a long-sleeved shirt, long pants, socks and shoes.

Use mosquito repellent.

Drain water and fill up low areas

Avoiding Mosquito Bites When Traveling To Another Country

Reduce mosquito habitat. The mosquitoes that carry the dengue virus typically live in and around houses, breeding in standing water that can collect in such things as used automobile tires. You can help lower mosquito populations by eliminating habitats where they lay their eggs. At least once a week, empty and clean containers that hold standing water.


  • It has been observed that sequential infection with any two of the four serotypes of dengue virus results in severe dengue infections in an endemic area
  • Serotype cross-reactive antibodies generated from previous primary infection with a particular dengue viral serotype are not highly specific for the other serotypes involved in secondary infections. Hence, they bind to the virions but do not neutralize them, and instead increase their uptake by cells like dendritic cells, monocytes and macrophages.
  • Such antibody-coated virions are taken up more rapidly than uncoated virus particles and this leads to enhanced antigen presentation by the infected dendritic cells to the T cells, leading to the more rapid activation and proliferation of memory T cells.
  • The cytokines produced by the activated T cells cause Endothelial cell dysfunction in dengue virus infection manifests as diffuse increase in capillary permeability, which is responsible for the microvascular leakage, hemoconcentration and circulatory insufficiency.

Cause of thrombocytopenia

  • Dengue viral infection is commonly associated with thrombocytopenia, the cause of which is molecular mimicry between dengue virus proteins and endogenous self proteins. There is generation of antibodies against dengue virus proteins (especially NSl), which cross-react with platelet surface proteins and thus cause thrombocytopenia.


  • BLOOD –CBC,CRP,Urea,Creatinine,FBS, SGOT ,SGPT,Serum electrolyte Na,K,CL,HCO3
  • Dengu NS1,IgG,IgM
  • Dengu PCR
  • Liver Function Test
  • Renal Function Test
  • Urine routine
  • Ct Chest
  • Ultrasound Abdomen



Leave a Comment