The Dengue virus is a mosquito-borne virus that causes dengue fever, a tropical disease characterized by high fever, severe headaches, joint and muscle pain, and rash. It is primarily transmitted by the Aedes aegypti mosquito, which thrives in urban areas. There are four distinct serotypes of the virus, meaning a person can be infected multiple times. Dengue fever is prevalent in many tropical and subtropical regions, including parts of Southeast Asia, Latin America, and Africa. While most cases are mild, severe dengue can lead to serious complications, including hemorrhagic fever and shock, requiring immediate medical attention.