HORSE ( DEAD- END HOST)

Eastern and western equine encephalomyelitis have similar life cycles, but they are spread by different mosquito vectors. EEE is generally carried by Culiseta melanura; WEE is usually spread by Culex tarsalis. WEE virus is also amplified by small birds and is spread primarily by a different mosquito vector, Culex tarsalis, which breeds in irrigation ditches in agricultural areas as well as in natural ponds and waterways west of the Mississippi River. No outbreaks of WEE have occurred in recent years. However, the virus is still found in surveys of birds and mosquitoes, and an outbreak remains a possibility.