Dengue fever is a mosquito-borne tropical disease caused by the dengue virus.

• Dengue is a mosquito-borne viral infection.
• The virus responsible for causing dengue, is called dengue virus (DENV). There are four DENV serotypes, meaning that it is possible to be infected four times.
• While many DENV infections produce only mild illness, DENV can cause an acute flu-like illness. Occasionally this develops into a potentially lethal complication, called severe dengue.
• Severe dengue is a leading cause of serious illness and death in some Asian and Latin American countries. It requires management by medical professionals.
• There is no specific treatment for dengue/severe dengue. Early detection of disease progression associated with severe dengue, and access to proper medical care lowers fatality rates of severe dengue to below 1%.
• Dengue is found in tropical and sub-tropical climates worldwide, mostly in urban and semi-urban areas.
• The global incidence of dengue has grown dramatically in recent decades. About half of the world’s population is now at risk. There are an estimated 100-400 million infections each year.
• Dengue prevention and control depends on effective vector control measures. Sustained community involvement can improve vector control efforts substantially.
  

  Symptoms

  Symptoms include high fever, headache, rash and muscle and joint pain. In severe cases there is serious bleeding and shock, which can be life threatening.

               Pain areas: In the abdomen, back, back of the eyes, bones, joints, or muscles

               Whole body: Chills, fatigue, fever, or loss of appetite

               Gastrointestinal: Nausea or vomiting

               Skin: Rashes or red spots

               Also common: Easy bruising or headache

  Transmission

  The virus is transmitted to humans through the bites of infected female mosquitoes, primarily the Aedes aegypti mosquito. Other species within the Aedes genus can also act as vectors, but their contribution is secondary to Aedes aegypti.

  After feeding on an DENV-infected person, the virus replicates in the mosquito midgut, before it disseminates to secondary tissues, including the salivary glands. The time it takes from ingesting the virus to actual transmission to a new host is termed the extrinsic incubation period (EIP). The EIP takes about 8-12 days when the ambient temperature is between 25-28°C . Variations in the extrinsic incubation period are not only influenced by ambient temperature; a number of factors such as the magnitude of daily temperature fluctuations, virus genotype , and initial viral concentration  can also alter the time it takes for a mosquito to transmit virus. Once infectious, the mosquito is capable of transmitting virus for the rest of its life