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Datasheet
West Nile virus
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Pictures
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| Picture | Title | Caption | Copyright |
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 | Title | Virions |
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| Caption | Electron micrograph of West Nile virions. Original magnification was approx. 50,000X. Scale bar in photo represents 300 nm.
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| Copyright | Diagnostic Virology Laboratory of the National Veterinary
Services Laboratory, VS, APHIS, USDA. |
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| Virions | Electron micrograph of West Nile virions. Original magnification was approx. 50,000X. Scale bar in photo represents 300 nm.
| Diagnostic Virology Laboratory of the National Veterinary
Services Laboratory, VS, APHIS, USDA. |
 | Title | Eggs |
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| Caption | Culex quinquefasciatus (southern house mosquito); egg raft. USA. |
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| Copyright | Public Domain/released by CDC (Centers for Disease Control and Prevention) - Original photograph by Harry Weinburgh |
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| Eggs | Culex quinquefasciatus (southern house mosquito); egg raft. USA. | Public Domain/released by CDC (Centers for Disease Control and Prevention) - Original photograph by Harry Weinburgh |
 | Title | Female Aedes mosquito |
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| Caption | Aedes albopictus (Asian tiger mosquito); adult female, inserting mouthparts to feed on a human host. |
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| Copyright | Public Domain/released by Centers for Disease Control - original image by James Gathany. |
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| Female Aedes mosquito | Aedes albopictus (Asian tiger mosquito); adult female, inserting mouthparts to feed on a human host. | Public Domain/released by Centers for Disease Control - original image by James Gathany. |
 | Title | Female |
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| Caption | Aedes albopictus (Asian tiger mosquito); close-up of an adult female, inserting mouthparts to feed on a human host. |
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| Copyright | Public Domain/released by Centers for Disease Control - original image by James Gathany. |
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 |
| Female | Aedes albopictus (Asian tiger mosquito); close-up of an adult female, inserting mouthparts to feed on a human host. | Public Domain/released by Centers for Disease Control - original image by James Gathany. |
 | Title | Female |
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| Caption | Aedes albopictus (Asian tiger mosquito); adult female, feeding on a human host. Note the hugely distended abdomen, indicating that she is almost fully engorged. |
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| Copyright | Public Domain/released by Centers for Disease Control - original image by James Gathany. |
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 |
| Female | Aedes albopictus (Asian tiger mosquito); adult female, feeding on a human host. Note the hugely distended abdomen, indicating that she is almost fully engorged. | Public Domain/released by Centers for Disease Control - original image by James Gathany. |
 | Title | Mated pair |
|---|
| Caption | Aedes albopictus (Asian tiger mosquito); a pair of mosquitoes during their mating ritual, while the partially engorged female continues to feed on her human host. |
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| Copyright | Public Domain/released by Centers for Disease Control - original image by James Gathany. |
|---|
 |
| Mated pair | Aedes albopictus (Asian tiger mosquito); a pair of mosquitoes during their mating ritual, while the partially engorged female continues to feed on her human host. | Public Domain/released by Centers for Disease Control - original image by James Gathany. |
Identity
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Preferred Scientific Name
- West Nile virus Heinz et al., 2000
Other Scientific Names
International Common Names
English acronym
Taxonomic Tree
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- Domain: Virus
- Unknown: "Positive sense ssRNA viruses"
- Unknown: "RNA viruses"
- Order: Nidovirales
- Family: Flaviviridae
- Genus: Flavivirus
- Species: West Nile virus
Distribution Table
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The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.
Pathogen Characteristics
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WNV virions are approximately 40 nm in diameter, spherical and contain a lipid envelope. The positive-sense single stranded RNA genome is 11.3 kb in size and contains three structural and seven non-structural proteins. The structural proteins comprise a capsid protein (C), the major envelope protein (E) and either a prM (immature virion) or M (mature virion). WNV is stable at an alkaline pH of 8.0 but is readily inactivated by acidic pH, temperatures above 40°C, organic solvents, detergents, UV-light and gamma-irradiation.
Two genetic lineages have been described (Berthet et al., 1997). Lineage 1 includes isolates from Europe, the Middle East, Africa, India, Australia (KUNV) and from North America (Lanciotti et al., 1999). Lineage 2 includes isolates from West, Central and East Africa and Madagascar which have not been associated with disease outbreaks. Scherret et al. (2001) suggested on the basis of genetic and antigenic analyses that WN viruses should be subdivided into at least 6 subtypes.
The close antigenic relationship of WNV to other flaviviruses is demonstrated in binding assays such as ELISA and haemagglutination-inhibition (HI) using polyclonal and monoclonal antibodies. Neutralising assays are more discriminating, with the envelope glycoprotein E the main target for neutralising antibody. The E protein is also responsible for inducing protective immunity.
References
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Berthet FX; Zeller HG; Drouet MT; Rauzier J; Digoutte JP; Deubel V, 1997. Extensive nucleotide changes and deletions within the envelope glycoprotein gene of Euro-African West Nile viruses. Journal of General Virology, 78(9):2293-2297; 22 ref.
Lanciotti RS; Roehrig JT; Deubel V; Smith J; Parker M; Steele K; Crise B; Volpe KE; Crabtree MB; Schereet JH, 1999. Origin of the West Nile virus responsible for an outbreak of encephalitis in the northeastern United States. Science, 286(5448):2333-2337.
OIE, 2003. West Nile fever in Oman. Disease Information, 16(48).
OIE, 2004. West Nile fever in Belize in october 2003. Disease Information, 17(10).
OIE, 2005. West Nile fever in Cuba. Virus detection in equids. Disease Information, 18(7).
Scherret JH; Poidinger M; Mackenzie JS; Broom AK; Deubel V; Lipkin WI; Briese T; Gould EA; Hall RA, 2001. The relationships between West Nile and Kunjin Viruses. Emerging Infectious Diseases, 7(4):697-705.
Distribution Maps
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