West nile virus: Difference between revisions

Jump to navigation Jump to search
VisualWikitext
No edit summary
No edit summary
 
(32 intermediate revisions by 7 users not shown)
Line 1: Line 1:
'''For patient information click [[{{PAGENAME}} (patient information)|here]]'''.
__NOTOC__
{{West nile virus infection}}


{{Taxobox
{{About0|West nile virus infection}}
| name = ''West Nile virus''
| image = NIAID-west-Nile.jpg
| virus_group = iv
| familia  = ''[[Flaviviridae]]''
| genus = ''[[Flavivirus]]''
| species = '''''West Nile virus'''''
}}
{{Infobox_Disease
| Name          = West Nile Fever
| DiseasesDB    = 30025
| ICD10          = {{ICD10|A|92|3}}
| MeshID        = D014901
}}


{{West nile virus}}
{{CMG}}
{{CMG}}


==[[West nile virus overview|Overview]]==
==Overview==
WNV is an enveloped positive-sense ssRNA virus of 11000 base pairs (bp) that is considered a member of the Japanese encephalitis serocomplex. It belongs to the genus Flavivirus and family Flaviviridae. Its RNA encodes structural and non-structural proteins. Although 7 lineages of WNV have been described, only lineage 1 and 2 are clinically significant. The viral natural reservoir includes many species, such as humans, horses, dogs, and cats; but the main natural reservoir is birds.


==[[West nile virus historical perspective|Historical Perspective]]==
==Taxonomy==
Viruses; ssRNA viruses; ssRNA positive-strand viruses, no DNA stage; Flaviviridae; Flavivirus; Japanese encephalitis virus group<ref name=NCBI>{{cite web | title = West Nile Virus | url = http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=11082&lvl=3&lin=f&keep=1&srchmode=1&unlock }}</ref>


==[[West nile virus pathophysiology|Pathophysiology]]==
==Biology==


==[[West nile virus epidemiology and demographics|Epidemiology & Demographics]]==
{| style="float: right;"
| [[File:WNV2.jpg|200px|thumb|none| Presence of West Nile virus virions, in an isolate that was grown in a cell culture.<SMALL> ''Image provided by the CDC [http://phil.cdc.gov/phil/details.asp Centers for Disease Control and Prevention] ''<ref>{{Cite web | title = http://phil.cdc.gov/phil/details.asp | url = http://phil.cdc.gov/phil/details.asp}}</ref></SMALL>]]
|}
WNV is a member of Japanese encephalitis serocomplex and belongs to the [[genus]] [[Flavivirus]], family [[Flaviviridae]].  Other [[species]] of the this serocomplex include the [[St Louis encephalitis virus]] and the [[Japanese encephalitis virus]].<ref name="pmid23860989">{{cite journal| author=Petersen LR, Brault AC, Nasci RS| title=West Nile virus: review of the literature. | journal=JAMA | year= 2013 | volume= 310 | issue= 3 | pages= 308-15 | pmid=23860989 | doi=10.1001/jama.2013.8042 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=23860989  }} </ref>


==[[West nile virus epidemiology and demographics|Risk Factors]]==
The WNV has an icosahedral symmetry, with a smooth surface.<ref name="Mukhopadhyay2003">{{cite journal|last1=Mukhopadhyay|first1=S.|title=Structure of West Nile Virus|journal=Science|volume=302|issue=5643|year=2003|pages=248–248|issn=0036-8075|doi=10.1126/science.1089316}}</ref>  It is an enveloped virus with a nucleocapsid core built of [[RNA]] and [[capsid]] proteins.  Its [[genome]] is contained in a single-stranded [[RNA]] of about 11000 bp.<ref name="CampbellMarfin2002">{{cite journal|last1=Campbell|first1=Grant L|last2=Marfin|first2=Anthony A|last3=Lanciotti|first3=Robert S|last4=Gubler|first4=Duane J|title=West Nile virus|journal=The Lancet Infectious Diseases|volume=2|issue=9|year=2002|pages=519–529|issn=14733099|doi=10.1016/S1473-3099(02)00368-7}}</ref>  It contains a single open reading frame ([[ORF]]), a 5' untranslated region ([[UTR]]), and another 3' region which is also not translated. The ORF contains a single polyprotein that produces 3 smaller types of structure proteins and 7 of non-structural proteins following processing and translation.
* Structural proteins are responsible for the formation of the viral particle and include:
:* Envelope proteins
:* Membrane proteins
:* C proteins
* Non-structural proteins are responsible for viral replication, evasion of the immune system, and assembly of virions. They include:
:*NS1
:*NS2A
:*NS2B
:*NS3
:*NS4A
:*NS4B
:*NS5


==[[West nile virus screening|Screening]]==
The WNV may be classified in 7 phylogenetic lineages.  Of these, only 1 and 2 have been identified as causative agents of disease in humans and are considered clinically significant.<ref name=CDC>{{cite web | title = West Nile Virus | url = http://wwwnc.cdc.gov/eid/article/10/1/pdfs/02-0616.pdf }}</ref><ref name="pmid12890319">{{cite journal| author=Miller DL, Mauel MJ, Baldwin C, Burtle G, Ingram D, Hines ME et al.| title=West Nile virus in farmed alligators. | journal=Emerg Infect Dis | year= 2003 | volume= 9 | issue= 7 | pages= 794-9 | pmid=12890319 | doi=10.3201/eid0907.030085 | pmc=PMC3023431 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12890319  }} </ref><ref name="pmid16704810">{{cite journal| author=Bakonyi T, Ivanics E, Erdélyi K, Ursu K, Ferenczi E, Weissenböck H et al.| title=Lineage 1 and 2 strains of encephalitic West Nile virus, central Europe. | journal=Emerg Infect Dis | year= 2006 | volume= 12 | issue= 4 | pages= 618-23 | pmid=16704810 | doi=10.3201/eid1204.051379 | pmc=PMC3294705 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16704810  }} </ref><ref name="pmid14585341">{{cite journal| author=Charrel RN, Brault AC, Gallian P, Lemasson JJ, Murgue B, Murri S et al.| title=Evolutionary relationship between Old World West Nile virus strains. Evidence for viral gene flow between Africa, the Middle East, and Europe. | journal=Virology | year= 2003 | volume= 315 | issue= 2 | pages= 381-8 | pmid=14585341 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=14585341  }} </ref><ref name="pmid12093177">{{cite journal| author=Lanciotti RS, Ebel GD, Deubel V, Kerst AJ, Murri S, Meyer R et al.| title=Complete genome sequences and phylogenetic analysis of West Nile virus strains isolated from the United States, Europe, and the Middle East. | journal=Virology | year= 2002 | volume= 298 | issue= 1 | pages= 96-105 | pmid=12093177 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12093177  }} </ref><ref name="pmid21781205">{{cite journal| author=Papa A, Xanthopoulou K, Gewehr S, Mourelatos S| title=Detection of West Nile virus lineage 2 in mosquitoes during a human outbreak in Greece. | journal=Clin Microbiol Infect | year= 2011 | volume= 17 | issue= 8 | pages= 1176-80 | pmid=21781205 | doi=10.1111/j.1469-0691.2010.03438.x | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21781205  }} </ref><ref name="pmid22406344">{{cite journal| author=Savini G, Capelli G, Monaco F, Polci A, Russo F, Di Gennaro A et al.| title=Evidence of West Nile virus lineage 2 circulation in Northern Italy. | journal=Vet Microbiol | year= 2012 | volume= 158 | issue= 3-4 | pages= 267-73 | pmid=22406344 | doi=10.1016/j.vetmic.2012.02.018 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22406344  }} </ref><ref name="pmid21586266">{{cite journal| author=Valiakos G, Touloudi A, Iacovakis C, Athanasiou L, Birtsas P, Spyrou V et al.| title=Molecular detection and phylogenetic analysis of West Nile virus lineage 2 in sedentary wild birds (Eurasian magpie), Greece, 2010. | journal=Euro Surveill | year= 2011 | volume= 16 | issue= 18 | pages=  | pmid=21586266 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21586266  }} </ref>
* Lineage 1: Widespread, isolates from Europe, America, Middle East, India, Africa, and Australia
* Lingeage 2: Southern Africa, Madagascar, and Europe


==[[West nile virus causes|Causes]]==
==Natural reservoir==
Although WNV can infect humans and numerous animals, birds are its main [[natural reservoir]].<ref name="pmid23860989">{{cite journal| author=Petersen LR, Brault AC, Nasci RS| title=West Nile virus: review of the literature. | journal=JAMA | year= 2013 | volume= 310 | issue= 3 | pages= 308-15 | pmid=23860989 | doi=10.1001/jama.2013.8042 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=23860989  }} </ref><ref name="CampbellMarfin2002">{{cite journal|last1=Campbell|first1=Grant L|last2=Marfin|first2=Anthony A|last3=Lanciotti|first3=Robert S|last4=Gubler|first4=Duane J|title=West Nile virus|journal=The Lancet Infectious Diseases|volume=2|issue=9|year=2002|pages=519–529|issn=14733099|doi=10.1016/S1473-3099(02)00368-7}}</ref>


==[[West nile virus differential diagnosis|Differentiating West nile virus from other Diseases]]==
==Gallery==


==[[West nile virus natural history|Natural History, Complications & Prognosis]]==
<gallery>


==Diagnosis==
Image: Flavivirus13.jpeg| West Nile virus is a flavivirus commonly found in Africa, West Asia, and the Middle East. <SMALL><SMALL>''[http://phil.cdc.gov/phil/home.asp From Public Health Image Library (PHIL).] ''<ref name=PHIL> {{Cite web | title = Public Health Image Library (PHIL) | url = http://phil.cdc.gov/phil/home.asp}}</ref></SMALL></SMALL>
[[West nile virus history and symptoms|History & Symptoms]] | [[West nile virus physical examination|Physical Examination]] | [[West nile virus laboratory tests|Lab Tests]] | [[West nile virus electrocardiogram|Electrocardiogram]] | |MRI]] | [[West nile virus other imaging findings|Other Imaging Findings]] | [[West nile virus other diagnostic studies|Other Diagnostic Studies]]


==Treatment==
Image: Flavivirus12.jpeg| This is a transmission electron micrograph (TEM) of the West Nile virus (WNV). <SMALL><SMALL>''[http://phil.cdc.gov/phil/home.asp From Public Health Image Library (PHIL).] ''<ref name=PHIL> {{Cite web | title = Public Health Image Library (PHIL) | url = http://phil.cdc.gov/phil/home.asp}}</ref></SMALL></SMALL>
[[West nile virus medical therapy|Medical Therapy]] | [[West nile virus surgery|Surgery]] | [[West nile virus primary prevention|Primary Prevention]] | [[West nile virus secondary prevention|Secondary Prevention]] | [[West nile virus future or investigational therapies|Future or investigational therapies]]


==Related Chapters==
Image: Flavivirus06.jpeg| Digitally-colorized transmission electron micrograph (TEM) of the West Nile virus (WNV). <SMALL><SMALL>''[http://phil.cdc.gov/phil/home.asp From Public Health Image Library (PHIL).] ''<ref name=PHIL> {{Cite web | title = Public Health Image Library (PHIL) | url = http://phil.cdc.gov/phil/home.asp}}</ref></SMALL></SMALL>
*[[CCR5]]
</gallery>


==Resources==
==References==
 
{{Reflist|2}}
{{commons|West Nile virus}}
* U.S. [[Centers for Disease Control and Prevention]] (CDC) pages
** [http://www.cdc.gov/ncidod/dvbid/westnile/ West Nile virus] topic page
** [http://www.cdc.gov/ncidod/dvbid/westnile/map.htm World map of West Nile and related viruses]
** [http://www.cdc.gov/ncidod/dvbid/westnile/surv&controlCaseCount03.htm 2003 case count]
* U.S. [[National Institute for Occupational Safety and Health]] (NIOSH) pages
** [http://www.cdc.gov/niosh/docs/2005-155/ Recommendations for Protecting Outdoor Workers from West Nile Virus Exposure]
** [http://www.cdc.gov/niosh/docs/2006-115/ Recommendations for Protecting Laboratory, Field, and Clinical Workers from West Nile Virus Exposure]
* [http://www.vrc.nih.gov Vaccine Research Center (VRC)] - Information concerning WNV vaccine research studies
* [http://westnilemaps.usgs.gov/us_human.html US map of West Nile virus]
* [http://www.phac-aspc.gc.ca/wnv-vwn/index.html Canadian Case Surveillance]
* L. Peterson, M. Marphin. [http://www.cfe.cornell.edu/erap/WNV/WNVEducDocs/Petersen-Marfin2002.pdf "West Nile virus: A Primer for the Clinician"], ''Annals of Internal Medicine,'' Vol. 137 No. 3, August 2002.
* D. J. White, D. L. Morse (eds.). "West Nile virus: Detection, Surveillance, and Control", [http://www.annalsnyas.org/content/vol951/issue1/ ''Annals of the New York Academy of Sciences''], Vol. 951, 2001.
* [http://www.nature.com/nsu/021014/021014-5.html ''Nature'' news article on West Nile paralysis]
* [http://www.cbc.ca/news/background/westnile/ CBC News Coverage of West Nile in Canada]
* [http://www.cdc.gov/ncidod/eid/vol5no5/hubalek.htm West Nile Fever in Europe]
* [http://www.encephalitisglobal.com Encephalitis Global, Inc.]
* [http://www.uos.harvard.edu/ehs/pes_wnv.shtml Harvard University fact sheet on West Nile Virus]
*[http://www.latimes.com/news/local/la-me-westnile19aug19,0,2186893.story?coll=la-home-local West Nile Cases Drop as Immunities Emerge, Experts Say]
* Nash D, Mostashari FM, Fine A, et al. N Engl J Med. 2001 [[June 14]];344(24):1807-14 [http://www.ncbi.nlm.nih.gov.arugula.cc.columbia.edu:2048/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=11407341&query_hl=1&itool=pubmed_docsum The outbreak of West Nile virus infection in the New York City Area in 1999]
 
[[zh-min-nan:Se Nî-lô-hô pēⁿ-to̍k]]
[[ca:Virus del Nil Occidental]]
[[de:West-Nil-Virus]]
[[es:Virus del Nilo Occidental]]
[[fr:Virus du Nil occidental]]
[[id:Virus West Nile]]
[[it:Virus del Nilo occidentale]]
[[he:קדחת הנילוס המערבי]]
[[lt:Nilo karštinė]]
[[nl:West-Nijlvirus]]
[[ja:ウエストナイル熱]]
[[pt:Nilo ocidental]]
[[zh:西尼羅河病毒]]
 
 
{{WikiDoc Help Menu}}
{{WS}}
 
[[Category:Disease]]
[[Category:Infectious disease]]
[[Category:Neurology]]
 
[[Category:Flaviviruses]]
[[Category:Viral diseases]]
[[Category:Zoonoses]]
[[Category:Tropical disease]]
[[Category:Insect-borne diseases]]
[[Category:Overview complete]]

Latest revision as of 14:24, 4 May 2016

West nile virus infection Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating West nile virus infection from other Diseases

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

History and Symptoms

Physical Examination

Laboratory Findings

Electrocardiogram

Chest X Ray

CT

MRI

Echocardiography or Ultrasound

Other Imaging Findings

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Primary Prevention

Secondary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

West nile virus On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of West nile virus

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on West nile virus

CDC on West nile virus

West nile virus in the news

Blogs on West nile virus

Directions to Hospitals Treating West nile virus infection

Risk calculators and risk factors for West nile virus

This page is about microbiologic aspects of the organism(s).  For clinical aspects of the disease, see West nile virus infection.

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

WNV is an enveloped positive-sense ssRNA virus of 11000 base pairs (bp) that is considered a member of the Japanese encephalitis serocomplex. It belongs to the genus Flavivirus and family Flaviviridae. Its RNA encodes structural and non-structural proteins. Although 7 lineages of WNV have been described, only lineage 1 and 2 are clinically significant. The viral natural reservoir includes many species, such as humans, horses, dogs, and cats; but the main natural reservoir is birds.

Taxonomy

Viruses; ssRNA viruses; ssRNA positive-strand viruses, no DNA stage; Flaviviridae; Flavivirus; Japanese encephalitis virus group[1]

Biology

Presence of West Nile virus virions, in an isolate that was grown in a cell culture. Image provided by the CDC Centers for Disease Control and Prevention [2]

WNV is a member of Japanese encephalitis serocomplex and belongs to the genus Flavivirus, family Flaviviridae. Other species of the this serocomplex include the St Louis encephalitis virus and the Japanese encephalitis virus.[3]

The WNV has an icosahedral symmetry, with a smooth surface.[4] It is an enveloped virus with a nucleocapsid core built of RNA and capsid proteins. Its genome is contained in a single-stranded RNA of about 11000 bp.[5] It contains a single open reading frame (ORF), a 5' untranslated region (UTR), and another 3' region which is also not translated. The ORF contains a single polyprotein that produces 3 smaller types of structure proteins and 7 of non-structural proteins following processing and translation.

  • Structural proteins are responsible for the formation of the viral particle and include:
  • Envelope proteins
  • Membrane proteins
  • C proteins
  • Non-structural proteins are responsible for viral replication, evasion of the immune system, and assembly of virions. They include:
  • NS1
  • NS2A
  • NS2B
  • NS3
  • NS4A
  • NS4B
  • NS5

The WNV may be classified in 7 phylogenetic lineages. Of these, only 1 and 2 have been identified as causative agents of disease in humans and are considered clinically significant.[6][7][8][9][10][11][12][13]

  • Lineage 1: Widespread, isolates from Europe, America, Middle East, India, Africa, and Australia
  • Lingeage 2: Southern Africa, Madagascar, and Europe

Natural reservoir

Although WNV can infect humans and numerous animals, birds are its main natural reservoir.[3][5]

Gallery

References

  1. ↑ "West Nile Virus".
  2. ↑ "http://phil.cdc.gov/phil/details.asp". External link in |title= (help)
  3. ↑ 3.0 3.1 Petersen LR, Brault AC, Nasci RS (2013). "West Nile virus: review of the literature". JAMA. 310 (3): 308–15. doi:10.1001/jama.2013.8042. PMID 23860989.
  4. ↑ Mukhopadhyay, S. (2003). "Structure of West Nile Virus". Science. 302 (5643): 248–248. doi:10.1126/science.1089316. ISSN 0036-8075.
  5. ↑ 5.0 5.1 Campbell, Grant L; Marfin, Anthony A; Lanciotti, Robert S; Gubler, Duane J (2002). "West Nile virus". The Lancet Infectious Diseases. 2 (9): 519–529. doi:10.1016/S1473-3099(02)00368-7. ISSN 1473-3099.
  6. ↑ "West Nile Virus" (PDF).
  7. ↑ Miller DL, Mauel MJ, Baldwin C, Burtle G, Ingram D, Hines ME; et al. (2003). "West Nile virus in farmed alligators". Emerg Infect Dis. 9 (7): 794–9. doi:10.3201/eid0907.030085. PMC 3023431. PMID 12890319.
  8. ↑ Bakonyi T, Ivanics E, Erdélyi K, Ursu K, Ferenczi E, Weissenböck H; et al. (2006). "Lineage 1 and 2 strains of encephalitic West Nile virus, central Europe". Emerg Infect Dis. 12 (4): 618–23. doi:10.3201/eid1204.051379. PMC 3294705. PMID 16704810.
  9. ↑ Charrel RN, Brault AC, Gallian P, Lemasson JJ, Murgue B, Murri S; et al. (2003). "Evolutionary relationship between Old World West Nile virus strains. Evidence for viral gene flow between Africa, the Middle East, and Europe". Virology. 315 (2): 381–8. PMID 14585341.
  10. ↑ Lanciotti RS, Ebel GD, Deubel V, Kerst AJ, Murri S, Meyer R; et al. (2002). "Complete genome sequences and phylogenetic analysis of West Nile virus strains isolated from the United States, Europe, and the Middle East". Virology. 298 (1): 96–105. PMID 12093177.
  11. ↑ Papa A, Xanthopoulou K, Gewehr S, Mourelatos S (2011). "Detection of West Nile virus lineage 2 in mosquitoes during a human outbreak in Greece". Clin Microbiol Infect. 17 (8): 1176–80. doi:10.1111/j.1469-0691.2010.03438.x. PMID 21781205.
  12. ↑ Savini G, Capelli G, Monaco F, Polci A, Russo F, Di Gennaro A; et al. (2012). "Evidence of West Nile virus lineage 2 circulation in Northern Italy". Vet Microbiol. 158 (3–4): 267–73. doi:10.1016/j.vetmic.2012.02.018. PMID 22406344.
  13. ↑ Valiakos G, Touloudi A, Iacovakis C, Athanasiou L, Birtsas P, Spyrou V; et al. (2011). "Molecular detection and phylogenetic analysis of West Nile virus lineage 2 in sedentary wild birds (Eurasian magpie), Greece, 2010". Euro Surveill. 16 (18). PMID 21586266.
  14. ↑ 14.0 14.1 14.2 "Public Health Image Library (PHIL)".
Retrieved from "https://www.wikidoc.org/index.php?title=West_nile_virus&oldid=1232270"