Systematic Veterinary Virology

EASTERN EQUINE ENCEPHALITIS

• The main mode of transmission and amplification of EEE is a mosquito-vertebrate-mosquito cycle.
• The primary mosquito vector for the EEE is the Culiseta melanura. Large numbers of these insects are found in swamp areas.
• During the late summer and early fall, mosquitoes leave the swamp breeding sites and move to drier, upland forested habitats.
• Aedes vexans and A canadensis mosquitoes (which breed in containers) are also believed to be responsible for bird to mammal transmission.
• The identification of vectors in epidemics is difficult because no single species is consistently associated with the transmission of the virus to horses and people.