Dengue virus is primarily transmitted by Aedes mosquitoes, particularly A. aegypti.[4] These mosquitoes usually live between the latitudes of 35° North and 35° South below an elevation of 1,000 metres (3,300 ft).[4] They typically bite during the day, particularly in the early morning and in the evening,[19][20] but they are able to bite and thus spread infection at any time of day all during the year.[21] Other Aedes species that transmit the disease include A. albopictus, A. polynesiensis and A. scutellaris.[4] Humans are the primary host of the virus,[4][14] but it also circulates in nonhuman primates.[22] An infection can be acquired via a single bite.[23] A female mosquito that takes a blood meal from a person infected with dengue fever, during the initial 2–10 day febrile period, becomes itself infected with the virus in the cells lining its gut.[24] About 8–10 days later, the virus spreads to other tissues including the mosquito's salivary glands and is subsequently released into its saliva. The virus seems to have no detrimental effect on the mosquito, which remains infected for life.[6] Aedes aegypti is particularly involved, as it prefers to lay its eggs in artificial water containers, to live in close proximity to humans, and to feed on people rather than other vertebrates.[6]