Editing West Nile fever (section)

==Epidemiology==
[[Image:Global distribution of West Nile virus-CDC.gif|thumb|upright=1.4|Global distribution of West Nile virus (2006)]]
{{See also|List of West Nile virus outbreaks|West Nile virus in the United States}}

WNV was first isolated from a feverish 37-year-old woman at Omogo in the [[West Nile sub-region|West Nile District]] of [[Uganda]] in 1937 during research on [[yellow fever virus]].<ref>{{cite journal |vauthors=Smithburn KC, Hughes TP, Burke AW, Paul JH |title=A Neurotropic Virus Isolated from the Blood of a Native of Uganda |journal=Am. J. Trop. Med. |volume=20 |issue=1|pages=471–92 |date=June 1940|doi=10.4269/ajtmh.1940.s1-20.471 |doi-access=free }}</ref>  A series of [[serosurvey]]s in 1939 in central Africa found anti-WNV positive results ranging from 1.4% (Congo) to 46.4% (White Nile region, Sudan). It was subsequently identified in [[Egypt]] (1942) and India (1953), a 1950 serosurvey in Egypt found 90% of those over 40 years in age had WNV antibodies. The ecology was characterized in 1953 with studies in [[Egypt]]<ref>{{cite journal |vauthors=Work TH, Hurlbut HS, Taylor RM |title=Isolation of West Nile virus from hooded crow and rock pigeon in the Nile delta |journal=Proc. Soc. Exp. Biol. Med. |volume=84 |issue=3|pages=719–22 |year=1953 |pmid=13134268 |doi=10.3181/00379727-84-20764 |s2cid=45962741 }}</ref> and [[Israel]].<ref>{{cite journal |vauthors=Bernkopf H, Levine S, Nerson R |title=Isolation of West Nile virus in Israel |journal=J. Infect. Dis. |volume=93 |issue=3 |pages=207–18 |year=1953|pmid=13109233 |doi=10.1093/infdis/93.3.207 }}</ref> The virus became recognized as a cause of severe human [[meningoencephalitis]] in elderly patients during an outbreak in Israel in 1957. The disease was first noted in horses in Egypt and France in the early 1960s and found to be widespread in southern Europe, southwest Asia and Australia.{{cn|date=September 2022}}

The first appearance of WNV in the Western Hemisphere was in 1999<ref name=Nash01>{{cite journal  |vauthors=Nash D, Mostashari F, Fine A, etal |title=The outbreak of West Nile virus infection in the New York City area in 1999 |journal=N. Engl. J. Med. |volume=344 |issue=24 |pages=1807–14 |date=June 2001 |pmid=11407341 |doi=10.1056/NEJM200106143442401|url=https://academicworks.cuny.edu/sph_pubs/24 |doi-access=free }}</ref>  with encephalitis reported in humans, dogs, cats, and horses, and the subsequent spread in the United States may be an important milestone in the evolving history of this virus. The American outbreak began in [[College Point, Queens]] in New York City and was later spread to the neighboring states of [[New Jersey]] and [[Connecticut]]. The virus is believed to have entered in an infected bird or mosquito, although there is no clear evidence.<ref>{{cite journal |author=Calisher CH |author1-link=Charles Calisher|title=West Nile virus in the New World: appearance, persistence, and adaptation to a new econiche—an opportunity taken |journal=Viral Immunol.|volume=13 |issue=4 |pages=411–4 |year=2000 |pmid=11192287 |doi=10.1089/vim.2000.13.411 }}</ref>  West Nile virus is now [[endemic]] in Africa, Europe, the Middle East, west and central Asia, Oceania (subtype [[Kunjin virus|Kunjin]]), and most recently, North America and is spreading into Central and South America.<ref>{{Cite book |url=https://books.google.com/books?id=7_vDDwAAQBAJ |title=Encyclopedia of Environmental Health |date=2019-08-22 |publisher=Elsevier |isbn=978-0-444-63952-3 |pages=452 |language=en}}</ref>

Outbreaks of West Nile virus encephalitis in humans have occurred in [[Algeria]] (1994), [[Romania]] (1996 to 1997), the Czech Republic (1997), [[Democratic Republic of the Congo|Congo]] (1998), Russia (1999), the United States (1999 to 2009), Canada (1999–2007), Israel (2000), Greece (2010), and Israel (2024).<ref>{{Cite book |last1=Bisen |first1=Prakash S. |url=https://books.google.com/books?id=FpoZGznXhTAC |title=Emerging Epidemics: Management and Control |last2=Raghuvanshi |first2=Ruchika |date=2013-06-14 |publisher=John Wiley & Sons |isbn=978-1-118-39325-3 |language=en}}</ref>

[[Epizootic]]s of disease in horses occurred in [[Morocco]] (1996), Italy (1998), the United States (1999 to 2001), and France (2000), Mexico (2003) and [[Sardinia]] (2011).{{cn|date=January 2023}}

In August 2024 in [[Warsaw]] the West Nile virus was identified in bodies of dead birds ([[Corvidae]]) while investigating an unusually high number of finds.<ref>{{Cite web|url = https://www.polsatnews.pl/wiadomosc/2024-08-13/tajemnicza-choroba-ptakow-w-warszawie-potwierdzily-sie-zle-informacje/|title = Tajemnicza choroba ptaków w Warszawie. Potwierdziły się złe informacje|date = August 13, 2024}}</ref>

Outdoor workers (including biological fieldworkers, construction workers, farmers, landscapers, and painters), healthcare personnel, and laboratory personnel who perform necropsies on animals are at risk of contracting WNV.<ref>{{Cite web|url = https://www.cdc.gov/niosh/topics/westnile/|title = West Nile virus|date = August 27, 2012|publisher = NIOSH|url-status = live|archive-url = https://web.archive.org/web/20170729073111/https://www.cdc.gov/niosh/topics/westnile/|archive-date = July 29, 2017}}</ref>

In 2012, the US experienced one of its worst [[epidemic]]s in which 286 people died, with the state of Texas being hard hit by this virus.<ref name="pmid24210089">{{cite journal |vauthors=Murray KO, Ruktanonchai D, Hesalroad D, Fonken E, Nolan MS |title=West Nile virus, Texas, USA, 2012 |journal=Emerging Infectious Diseases |volume=19 |issue=11 |pages=1836–8 |date=November 2013  |pmid=24210089 |pmc=3837649 |doi=10.3201/eid1911.130768 }}</ref><ref>{{cite news|title=2012 was deadliest year for West Nile in US, CDC says|author=Fox, M.|url=http://vitals.nbcnews.com/_news/2013/05/13/18232095-2012-was-deadliest-year-for-west-nile-in-us-cdc-says|newspaper=NBC News|date=May 13, 2013|access-date=May 13, 2013|url-status=live|archive-url=https://web.archive.org/web/20130608042431/http://vitals.nbcnews.com/_news/2013/05/13/18232095-2012-was-deadliest-year-for-west-nile-in-us-cdc-says|archive-date=June 8, 2013}}</ref>

=== Weather ===
Drought has been associated with a higher number of West Nile virus cases in the following year.<ref name=Bro2014>{{Cite journal|last1=Brown|first1=L.|last2=Medlock|first2=J.|last3=Murray|first3=V.|date=January 2014|title=Impact of drought on vector-borne diseases – how does one manage the risk?|journal=Public Health|volume=128|issue=1|pages=29–37|doi=10.1016/j.puhe.2013.09.006|pmid=24342133|issn=0033-3506}}</ref> As drought can decrease fish and other populations that eat mosquito eggs, higher numbers of mosquitoes can result.<ref name=Bro2014/> Higher temperatures are linked to decreased time for replication and increased viral load in birds and mosquitoes.<ref name=Paz2015>{{Cite journal|last=Paz|first=Shlomit|date=2015-04-05|title=Climate change impacts on West Nile virus transmission in a global context|journal=Philosophical Transactions of the Royal Society B: Biological Sciences|volume=370|issue=1665|pages=20130561|doi=10.1098/rstb.2013.0561|issn=0962-8436|pmid=25688020|pmc=4342965}}</ref>