Editing West Nile fever (section)

==Signs and symptoms==
About 80% of those infected with [[West Nile virus]] (WNV) show [[asymptomatic|no symptoms]] and go unreported.<ref>{{cite web |last1=Gompf |first1=Sandra |title=West Nile Virus |url=https://www.medicinenet.com/west_nile_encephalitis/article.htm |website=Medicine Net |publisher=MedicineNet Inc. |access-date=15 January 2019}}</ref> About 20% of infected people develop symptoms. These vary in severity, and begin 3 to 14 days after being bitten. Most people with mild symptoms of WNV recover completely, though fatigue and weakness may last for weeks or months. Symptoms may range from mild, such as [[fever]], to severe, such as [[paralysis]] and [[meningitis]]. A severe infection can last weeks and can, rarely, cause [[permanent brain damage]]. [[Death]] may ensue if the central nervous system is affected. Medical conditions such as [[cancer]] and [[diabetes]], and age over 60 years, increase the risk of developing severe symptoms.<ref>{{cite web |title=Symptoms, Diagnosis, & Treatment |url=https://www.cdc.gov/westnile/symptoms/index.html |website=Centers for Disease Control and Prevention |publisher=USA.gov |access-date=15 January 2019|date=2018-12-10 }}</ref><ref>{{cite web |title=West Nile virus |url=https://www.mayoclinic.org/diseases-conditions/west-nile-virus/diagnosis-treatment/drc-20350325 |website=Mayoclinic |publisher=Mayo Foundation for Medical Education and Research (MFMER) |access-date=15 January 2019}}</ref>

Headache can be a prominent symptom of WNV fever, meningitis, encephalitis, meningoencephalitis, and it may or may not be present in poliomyelitis-like syndrome. Thus, headache is not a useful indicator of neuroinvasive disease.
* West Nile fever (WNF), which occurs in 20 percent of cases, is a [[fever|febrile]] [[syndrome]] that causes [[flu-like symptoms]].<ref>{{cite journal |author=Olejnik E |title=Infectious adenitis transmitted by ''Culex molestus'' |journal=Bull Res Counc Isr |volume=2 |pages=210–1 |year=1952}}</ref> Most characterizations of WNF describe it as a mild, [[acute (medicine)|acute]] syndrome lasting 3 to 6 days after symptom onset. Systematic follow-up studies of patients with WNF have not been done, so this information is largely [[Anecdotal evidence|anecdotal]]. Possible symptoms include high fever, headache, chills, [[diaphoresis|excessive sweating]], weakness, fatigue, [[lymphadenopathy|swollen lymph nodes]], drowsiness, pain in the joints and [[flu-like symptoms]]. There may be [[Human gastrointestinal tract|gastrointestinal]] symptoms including [[nausea]], [[emesis|vomiting]], [[Anorexia (symptom)|loss of appetite]], and [[diarrhea]]. Fewer than one-third of patients develop a [[rash]].
* West Nile [[Neurotropic virus|neuroinvasive disease]] (WNND), which occurs in less than 1 percent of cases, is when the virus infects the [[central nervous system]] resulting in [[meningitis]], [[encephalitis]], meningoencephalitis or a [[poliomyelitis]]-like syndrome.<ref name="Davis2006">{{cite journal |vauthors=Davis LE, DeBiasi R, Goade DE, etal |date=Sep 2006 |title=West Nile virus neuroinvasive disease |journal=[[Annals of Neurology]] |volume=60 |issue=3 | pages=286–300 |pmid=16983682 |doi=10.1002/ana.20959|s2cid=30778922 }}</ref> Many patients with WNND have normal [[neuroimaging]] studies, although abnormalities may be present in various cerebral areas including the [[basal ganglia]], [[thalamus]], [[cerebellum]], and [[brainstem]].<ref name="Davis2006" />
* West Nile virus encephalitis (WNE) is the most common neuroinvasive manifestation of WNND. WNE presents with similar symptoms to other viral encephalitis with fever, headaches, and altered mental status. A prominent finding in WNE is [[muscular weakness]] (30 to 50 percent of patients with encephalitis), often with [[lower motor neuron]] symptoms, [[flaccid paralysis]], and [[hyporeflexia]] with no [[Sensory system|sensory]] abnormalities.<ref>{{cite journal |vauthors=Flores Anticona EM, Zainah H, Ouellette DR, Johnson LE |title=Two case reports of neuroinvasive west nile virus infection in the critical care unit |journal=Case Reports in Infectious Diseases |volume=2012 |pages=1–4 |year=2012 |pmid=22966470 |pmc=3433121 |doi=10.1155/2012/839458|doi-access=free }}</ref><ref name=Carson06>{{cite journal |vauthors=Carson PJ, Konewko P, Wold KS, etal |title=Long-term clinical and neuropsychological outcomes of West Nile virus infection |journal=[[Clinical Infectious Diseases]] |volume=43 |issue=6 |pages=723–30 |year=2006 |pmid=16912946 |doi=10.1086/506939 |s2cid=2765866 |url=https://academic.oup.com/cid/article-pdf/43/6/723/933835/43-6-723.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://academic.oup.com/cid/article-pdf/43/6/723/933835/43-6-723.pdf |archive-date=2022-10-09 |url-status=live}}</ref>
* West Nile meningitis (WNM) usually involves fever, headache, stiff neck and [[pleocytosis]], an increase of white blood cells in cerebrospinal fluid. Changes in consciousness are not usually seen and are mild when present.
* West Nile meningoencephalitis is inflammation of both the brain (encephalitis) and meninges (meningitis).
* West Nile poliomyelitis (WNP), an [[acute flaccid paralysis]] syndrome associated with WNV infection, is less common than WNM or WNE. This syndrome is generally characterized by the acute onset of asymmetric limb weakness or paralysis in the absence of sensory loss. Pain sometimes precedes the paralysis. The paralysis can occur in the absence of fever, headache, or other common symptoms associated with WNV infection. Involvement of respiratory muscles, leading to acute respiratory failure, sometimes occurs.
* West-Nile reversible paralysis, Like WNP, the weakness or paralysis is asymmetric.<ref name="Mojumder2014">{{cite journal |author=Mojumder, D.K., Agosto, M., Wilms, H. |date=March 2014 |title=Is initial preservation of deep tendon reflexes in West Nile Virus paralysis a good prognostic sign? |journal=Neurology Asia |volume=19 |issue=1 |pages=93–97 |display-authors=etal |pmid=25400704 |pmc=4229851}}</ref> Reported cases have been noted to have an initial preservation of deep tendon reflexes, which is not expected for a pure anterior horn involvement.<ref name="Mojumder2014"/> Disconnect of upper motor neuron influences on the anterior horn cells possibly by myelitis or glutamate excitotoxicity have been suggested as mechanisms.<ref name="Mojumder2014"/> The prognosis for recovery is excellent.
* Nonneurologic complications of WNV infection that may rarely occur include fulminant [[hepatitis]], [[pancreatitis]],<ref>{{cite journal |vauthors=Asnis DS, Conetta R, Teixeira AA, Waldman G, Sampson BA |title=The West Nile Virus outbreak of 1999 in New York: the Flushing Hospital experience |journal=Clinical Infectious Diseases |volume=30 |issue=3 |pages=413–8 |date=March 2000 |pmid=10722421 |doi=10.1086/313737|doi-access=free }}</ref> [[myocarditis]], [[rhabdomyolysis]],<ref>{{cite journal |vauthors=Montgomery SP, Chow CC, Smith SW, Marfin AA, O'Leary DR, Campbell GL |title=Rhabdomyolysis in patients with west nile encephalitis and meningitis |journal=Vector-Borne and Zoonotic Diseases |volume=5 |issue=3 |pages=252–7 |year=2005 |pmid=16187894 |doi=10.1089/vbz.2005.5.252|s2cid=33442661 }}</ref> [[orchitis]],<ref>{{cite journal |vauthors=Smith RD, Konoplev S, DeCourten-Myers G, Brown T |title=West Nile virus encephalitis with myositis and orchitis |journal=Hum. Pathol. |volume=35 |issue=2 |pages=254–8 |date=February 2004 |pmid=14991545 |doi=10.1016/j.humpath.2003.09.007 }}</ref> [[nephritis]], [[optic neuritis]]<ref>{{cite journal |vauthors=Anninger WV, Lomeo MD, Dingle J, Epstein AD, Lubow M |title=West Nile virus-associated optic neuritis and chorioretinitis |journal=Am. J. Ophthalmol. |volume=136 |issue=6 |pages=1183–5 |year=2003|pmid=14644244 |doi=10.1016/S0002-9394(03)00738-4}}</ref> and [[cardiac dysrhythmia]]s and [[hemorrhagic fever]] with [[coagulopathy]].<ref>{{cite journal |vauthors=Paddock CD, Nicholson WL, Bhatnagar J, etal |title=Fatal hemorrhagic fever caused by West Nile virus in the United States |journal=Clinical Infectious Diseases |volume=42 |issue=11 |pages=1527–35 |date=June 2006 |pmid=16652309 |doi=10.1086/503841|doi-access= }}</ref> [[Chorioretinitis]] may also be more common than previously thought.<ref>{{cite journal |vauthors=Shaikh S, Trese MT |title=West Nile virus chorioretinitis |journal=Br J Ophthalmol |volume=88 |issue=12 |pages=1599–60 |year=2004 |pmid=15548822 |pmc=1772450 |doi=10.1136/bjo.2004.049460}}</ref>
* Skin manifestations, specifically rashes, are common; however, there are few detailed descriptions in case reports, and few images are available. Punctate erythematous, macular, and papular eruptions, most pronounced on the extremities have been observed in WNV cases and in some cases histopathologic findings have shown a sparse superficial [[Pericyte|perivascular]] lymphocytic infiltrate, a manifestation commonly seen in viral exanthems. A literature review provides support that this punctate rash is a common cutaneous presentation of WNV infection.<ref>{{cite journal |vauthors=Anderson RC, Horn KB, Hoang MP, Gottlieb E, Bennin B |title=Punctate exanthem of West Nile Virus infection: report of 3 cases |journal=J. Am. Acad. Dermatol. |volume=51 |issue=5 |pages=820–3 |date=November 2004 |pmid=15523368 |doi=10.1016/j.jaad.2004.05.031}}</ref>