The dengue virus is a mosquito-borne virus of the family Flaviviridae, genus Orthoflavivirus. It consists of a single positive-sense RNA genome inside an enveloped capsid. Four antigenically distinct serotypes (DENV‑1 to DENV‑4) infect humans. The virus is transmitted primarily by Aedes aegypti mosquitoes and causes dengue fever.
## Explanation
The dengue virus has a spherical, enveloped particle about 50 nanometres in diameter. Its genome encodes a single polyprotein that is cleaved into structural proteins (capsid, membrane and envelope) and nonstructural proteins required for replication. After a mosquito ingests viremic blood, the virus infects and replicates in the mosquito’s midgut and salivary glands. When that mosquito bites a person, the virus enters skin dendritic cells and then spreads to lymph nodes and the bloodstream. Dengue fever typically begins after an incubation period of 4–10 days with high fever, headache, severe muscle and joint pain, and rash【618573500755251†L580-L604】. Most infections are self‑limited, but a small proportion progress to severe dengue with plasma leakage, bleeding or organ impairment. Secondary infection with a different serotype increases the risk of severe disease due to antibody‑dependent enhancement. There is no specific antiviral therapy; management focuses on maintaining fluid balance and monitoring for warning signs. A live attenuated vaccine is licensed in some countries, and several other candidates are under investigation. Control efforts rely on reducing mosquito breeding sites, using insecticides and personal protective measures such as bed nets and repellents.
## Transmission and control
Dengue is endemic in more than 100 countries, and about half of the world’s population lives in areas at risk【618573500755251†L580-L604】. Outbreaks occur in tropical and subtropical regions, including parts of Asia, the Americas and Africa. Urbanisation, travel and climate change facilitate the spread of Aedes mosquitoes and the virus. Surveillance and laboratory testing are important for early detection and management of outbreaks. Vector control programs often include removing standing water, covering water storage containers and releasing mosquitoes infected with Wolbachia bacteria to reduce virus transmission. Public education about eliminating breeding sites and seeking medical care promptly can reduce morbidity and mortality.
Dengue virus remains a significant public health challenge. Early diagnosis, supportive care and integrated vector management are key to reducing disease burden.
**Related Terms:** Mosquito, Flavivirus, Dengue fever, Vector, Aedes