DENV4

DENV-4, or dengue virus type 4, is one of the four serotypes of the dengue virus (DENV-1–DENV-4) in the Flaviviridae family. Like the other serotypes, it is transmitted to humans mainly by Aedes mosquitoes, principally Aedes aegypti and Aedes albopictus, and occurs in tropical and subtropical regions around the world.

The virus has a positive-sense single-stranded RNA genome of about 11 kilobases. The genome encodes a single polyprotein that is cleaved to yield three structural proteins—capsid (C), premembrane/membrane (prM/M), and envelope (E)—and seven nonstructural proteins (NS1–NS5). The envelope protein is the major target of neutralizing antibodies and drives serotype-specific immunity.

Ecology and transmission involve urban and peri-urban cycles in which infected humans serve as the source of virus for biting mosquitoes. DENV-4 often co-circulates with other dengue serotypes, and outbreaks have occurred in the Americas, Asia, and other regions. Immunity after infection with one serotype does not confer long-lasting protection against others; subsequent infection with a different serotype, including DENV-4, can heighten the risk of severe dengue through mechanisms such as antibody-dependent enhancement in some cases.

Diagnosis is based on molecular methods such as RT-PCR during the acute phase, isolation of virus, or serology to detect dengue-specific IgM and IgG antibodies. Prevention focuses on reducing Aedes mosquito populations and exposure to bites; vaccines that provide tetravalent protection against all four serotypes are available in some countries, and recommendations depend on serostatus and local public health guidance.