title: Variations in biological features of West Nile viruses.
abstract: Pathological findings in humans, horses, and birds with West Nile (WN) encephalitis show neuronal degeneration and necrosis in the central nervous system (CNS), with diffuse inflammation. The mechanisms of WN viral penetration of the CNS and pathophysiology of the encephalitis remain largely unknown. Since 1996, several epizootics involving hundreds of humans, horses, and thousands of wild and domestic bird cases of encephalitis and mortality have been reported in Europe, North Africa, the Middle East, Russia, and the USA (see specific chapters in this issue). However, biological and molecular markers of virus virulence should be characterized to assess whether novel strains with increased virulence are responsible for this recent proliferation of outbreaks.
authors.affiliation: Institut Pasteur, Unité de Biologie des Infections Virales Emergentes, Lyon, France. vdeubel@cervi-lyon.inserm.fr
authors.forename: V
authors.initials: V
authors.lastname: Deubel
authors.forename: L
authors.initials: L
authors.lastname: Fiette
authors.forename: P
authors.initials: P
authors.lastname: Gounon
authors.forename: M T
authors.initials: MT
authors.lastname: Drouet
authors.forename: H
authors.initials: H
authors.lastname: Khun
authors.forename: M
authors.initials: M
authors.lastname: Huerre
authors.forename: C
authors.initials: C
authors.lastname: Banet
authors.forename: M
authors.initials: M
authors.lastname: Malkinson
authors.forename: P
authors.initials: P
authors.lastname: Desprès
mesh_terms: D000330:Aedes / Q000821:virology; D000818:Animals; D001717:Birds / Q000821:virology; D000882:Haplorhini / Q000821:virology; D006736:Horses / Q000821:virology; D006801:Humans; D051379:Mice / Q000821:virology; D014901:West Nile Fever / Q000473:pathology*; D014902:West Nile virus / Q000472:pathogenicity* / Q000648:ultrastructure