Mode of Transmission for Dengue Fever
Dengue fever is transmitted to humans through the bite of infected Aedes mosquitoes, primarily Aedes aegypti and Aedes albopictus, which are day-biting mosquitoes. 1, 2
Primary Vector Transmission
The principal mode of transmission is through the bite of infected female Aedes species mosquitoes, with Aedes aegypti being the primary vector and Aedes albopictus serving as a secondary vector. 3, 4, 5
These mosquitoes are diurnal (day-biting) insects, which distinguishes them from many other disease-carrying mosquitoes that bite primarily at dawn or dusk. 1, 5
The mosquitoes acquire the dengue virus when they feed on the blood of an infected human during the viremic phase (typically the first few days of illness), and subsequently transmit the virus to other humans through subsequent blood meals. 2, 4
Geographic and Environmental Context
Dengue transmission historically occurred in tropical and subtropical regions, but climate change and globalization have expanded the geographic range of competent Aedes vectors into more temperate regions, including parts of Europe and North America. 3
Rainfall and temperature are critical factors that affect mosquito breeding sites and the development of both the mosquito vector and the virus within the mosquito's body (extrinsic incubation period). 3
Unplanned urbanization and increased air travel have significantly contributed to the expansion of dengue's geographic and demographic distribution. 6
Alternative Transmission Routes (Rare)
Transfusion-transmitted dengue is a recognized but rare mode of transmission, with only five formally documented cases as of 2015, including one case of dengue hemorrhagic fever. 7
The American Association of Blood Banks placed dengue virus in the highest category of emerging infectious agents for potential impact on transfusion recipient safety. 7