The dengue virus is a mosquito-borne virus that causes dengue fever, a tropical disease. It is primarily transmitted by the Aedes aegypti mosquito, which thrives in urban areas. Symptoms of dengue fever include high fever, severe headaches, joint and muscle pain, and rash. In some cases, it can lead to severe dengue, which can be life-threatening. There are four distinct serotypes of the dengue virus, meaning a person can be infected multiple times. Prevention focuses on reducing mosquito populations and avoiding bites, as there is no specific antiviral treatment for the infection. Vaccines are available in some regions to help protect against the virus.