In general, Ae. aegypti is less susceptible to infection by DENV than Ae. albopictus, which could act as a selection mechanism for more virulent strains of DENV; the lower susceptibility would require a higher viral load in the human host in order to infect the mosquito. High viral titers in humans have been seen to be correlated to severe DHF/DSS. On the contrary, the secondary vector Ae. albopictus could transmit DENV strains that do not replicate to such high titers resulting in less clinically overt or severe disease. This scenario proposes that Ae. albopictus could function as a maintenance vector involved in the silent transmission of DENV during inter-epidemic periods. However, the susceptibility of the mosquito vector and transmission dynamics are also dependent on DENV strains, but the mechanisms underlying the inter-specific and inter-strain differences in vector susceptibility to DENV infection remains to be determined.