What is West Nile disease (encephalitis or meningitis)?
“Encephalitis” means an inflammation of the brain and can be caused by viruses and bacteria, including viruses transmitted by mosquitoes. West Nile encephalitis is an infection of the brain caused by West Nile virus, a flavivirus commonly found in Africa, West Asia and the Middle East. “Meningitis” is an inflammation of the covering of the brain. West Nile virus can also cause meningitis.