Figure 5.

DENV transmission cycles: (1) Wild forest animals are infected by the bites of mosquito-Aedes (blue line), this cycle is the sylvatic cycle. (2) The dwellings near the forests or within the sylvatic cycle are named the zones of emergence and/or re-emergence of the virus. The movement of populations infected by mosquito bites to urban areas leads to the urban cycle. (3) The urban cycle with transmission to urban mosquitoes, then transmission to humans induced by infected urban mosquitoes (blue line). (4) Transovarian transmission of infected mosquitoes is possible both in the forest and in urban areas (red circle).