Western equine encephalitis virus (WEEV) is an arbovirus that belongs to the Togaviridae family and Alphavirus genus. It is primarily found in the western regions of North America. WEEV is transmitted to humans and equines through the bite of infected mosquitoes, primarily those of the Culex tarsalis species.
WEEV is known to cause Western equine encephalitis (WEE), a rare but potentially severe neurological disease. The virus primarily affects horses, causing inflammation of the brain and spinal cord, leading to symptoms such as fever, weakness, lack of coordination, and sometimes paralysis. In humans, WEEV infection can result in fever, headache, nausea, vomiting, drowsiness, and in severe cases, encephalitis, which can lead to coma or even death.
The natural reservoirs for WEEV include wild birds, particularly passerines and shorebirds. Mosquitoes become infected with the virus when they feed on infected birds, and subsequently transmit it to other animals or humans during subsequent feedings.
Prevention and control of WEEV involve mosquito control measures, such as using insecticides, wearing protective clothing, and avoiding outdoor activities during peak mosquito activity times. In equines, vaccination is available to reduce the risk of infection. There is currently no specific antiviral treatment for WEEV in either humans or animals, and supportive care is the primary approach.
WEEV is considered a significant public health concern due to its potential to cause severe disease in both humans and horses.
