Dengue virus infection occurs when people are bitten by a mosquito carrying any one of four closely related viruses. In most cases, the disease causes a flu-like illness that passes on its own within a couple of weeks. However, more severe types of dengue virus infection can be fatal.

A mosquito known as Aedes aegypti is the most common carrier of dengue viruses. Mosquitoes often become infected after biting a person who has dengue. About a week later, the mosquito becomes contagious and passes the virus to other people after biting them.

Dengue infection usually occurs in tropical urban areas of the world, where Aedes aegypti mosquitoes live. However, the virus also can appear in other regions if people visit or return to those places after being infected in a tropical part of the world. Dengue infection can take several forms of varying severity. Symptoms of the first, dengue fever, typically include a sudden high fever and severe joint and muscle pain. Symptoms of the more severe and potentially life-threatening condition called dengue hemorrhagic fever include tendency to bruise easily, bleeding from the nose or gums, and internal bleeding.

Two blood tests performed two to three weeks apart can help diagnose dengue infection. These tests reveal the presence of antibodies created by the immune system in response to dengue infection.

Treatment of dengue virus infection varies depending on the nature of the illness. There is no standard treatment for dengue virus aside from rest and drinking plenty of fluids until the virus passes from the system, usually in about two weeks. Treatment of the more serious dengue hemorrhagic fever usually requires hospitalization and fluid and electrolyte replacement therapy.