Changes

Disease associated with EEE, WEE and VEE is largely restricted to the Western Hemisphere, ranging from temperate to desert climates.  EEE in the United States is mainly seen in the Southeastern United States but has been detected in all states east of the Mississippi River and some Western states.  Large outbreaks of WEE have been described in California and other Western states but the incidence of clinical disease in these areas has experienced a dramatic decrease. The reason for this unknown but may be due to geographical variation in virulence.  Equine disease associated with WEE is rare on the Eastern seaboard ofthe United States. VEE  virus is a very important human andveterinary pathogen in the Western Hemipshoere that can cause large outbreaks of disease in humans and horses over large geopgrahic areas.  VEE has spread into Central America, causing devastating epidemics as far north as Texas. The disease distribution is determined by climatic conditions as well as agricultural practices, such as irrigation, which favour the life cycle and spread of mosquitoes.

Disease associated with EEE, WEE and VEE is largely restricted to the Western Hemisphere, ranging from temperate to desert climates.  EEE in the United States is mainly seen in the Southeastern United States but has been detected in all states east of the Mississippi River and some Western states.  Large outbreaks of WEE have been described in California and other Western states but the incidence of clinical disease in these areas has experienced a dramatic decrease. The reason for this unknown but may be due to geographical variation in virulence.  Equine disease associated with WEE is rare on the Eastern seaboard ofthe United States. VEE  virus is a very important human andveterinary pathogen in the Western Hemipshoere that can cause large outbreaks of disease in humans and horses over large geopgrahic areas.  VEE has spread into Central America, causing devastating epidemics as far north as Texas. The disease distribution is determined by climatic conditions as well as agricultural practices, such as irrigation, which favour the life cycle and spread of mosquitoes.

WEE virus infection in horses is often observed over a wide geographical area, e.g. sporadic cases over 1000 square miles. EEE virus infections are usually observed in limited geographical areas

WEE virus infection in horses is often observed over a wide geographical area, e.g. sporadic cases over 1000 square miles. EEE virus infections are usually observed in limited geographical areas

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