a flavivirus (species West Nile virus of the genus Flavivirus) that causes an illness marked by fever, headache, muscle ache, skin rash, and sometimes encephalitis or meningitis and that is spread esp, a flavivirus originally isolated in eastern Africa, transmitted by mosquitoes, usually between birds, but sometimes causing epidemics of disease (typically fever or encephalitis) in humans and horses, virus belonging to the family Flaviviridae, related to viruses that can cause yellow fever and dengue and more closely to viruses that can cause encephalitis (inflammation of the brain), flaviviiruste hulka kuuluv ... viirus, mis on antigeenselt koostiselt sarnane Jaapani entsefaliidi viirusega