The main hosts of Kyasanur forest disease virus (KFDV) are small rodents, but shrews, bats, and monkeys may also carry the virus. KFD is transmitted from the bite of an infected tick (Haemaphysalis spinigera is the major vector). Humans can get these diseases from a tick bite or by contact with an infected animal, such as sick or recently dead monkey.

Larger animals such as goats, cows, and sheep may become infected with KFD, but they do not have a role in the transmission of the disease. Furthermore, there is no evidence of the disease being transmitted via the unpasteurized milk of any of these animals.