West Nile virus - Revision history

Aidan: /* Clinical Manifestations */

2025-08-21T16:02:49Z

Clinical Manifestations

← Older revision		Revision as of 16:02, 21 August 2025
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	* Up to 80% of infections are asymptomatic		* Up to 80% of infections are asymptomatic
	* Of the 20% with symptoms, [[fever]] is most common		* Of the 20% with symptoms, [[fever]] is most common
	** Other common symptoms include headaches, generalized weakness, morbilliform or maculopapular rash (often ~~occuring~~ at defervescence), and myalgias		** Other common symptoms include headaches, generalized weakness, morbilliform or maculopapular rash (often occurring at defervescence), and myalgias
	** Less common symptoms include arthralgias, chills, eye pain, vomiting, diarrhea, and lymphadenopathy		** Less common symptoms include arthralgias, chills, eye pain, vomiting, diarrhea, and lymphadenopathy
	** Generally self-resolves within days to weeks with complete recovery, though fatigue may linger		** Generally self-resolves within days to weeks with complete recovery, though fatigue may linger
			* CRP often elevated; mild leukocytosis, mild liver enzyme abnormalities

	=== West Nile Neuroinvasive Disease ===		=== West Nile Neuroinvasive Disease ===

Aidan: /* Differential Diagnosis */

2023-08-29T13:45:24Z

Differential Diagnosis

← Older revision		Revision as of 13:45, 29 August 2023
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	* West Nile Virus: Review of the Literature. ''JAMA.'' 2013;310(3):308–315. doi:[https://doi.org/10.1001/jama.2013.8042 10.1001/jama.2013.8042]		* West Nile Virus: Review of the Literature. ''JAMA.'' 2013;310(3):308–315. doi:[https://doi.org/10.1001/jama.2013.8042 10.1001/jama.2013.8042]
			* West Nile virus neuroinvasive disease. ''Ann Neurol.'' 2006;60:286-300. doi:[https://doi.org/10.1002/ana.20959 10.1002/ana.20959]

	[[Category:Flaviviridae]]		[[Category:Flaviviridae]]

Aidan at 13:41, 29 August 2023

2023-08-29T13:41:56Z

← Older revision		Revision as of 13:41, 29 August 2023
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	== Background ==		== Background ==

			=== Virology ===
	* Single-stranded positive-sense enveloped virus in the family [[Flaviviridae]] and genus [[Flavivirus]]		* Single-stranded positive-sense enveloped virus in the family [[Family::Flaviviridae]] and genus [[Genus::Flavivirus]], within the Japanese encephalitis serocomplex
			* Five lineages, of which only lineage 1 and 2 cause outbreaks in humans

			=== Epidemiology ===
	* Essentially worldwide distribution		* Essentially worldwide distribution
	* Vector is [[Vector::mosquitoes]]		* Vector is [[Vector::mosquitoes]], particularly [[Culex]] mosquitoes
	* Main reservoir is birds		* Main reservoir is birds, particularly crows, jays, magpies, and ravens; also horses
			** Humans are an incidental host and not generally involved in transmission
			* Disease in humans is seasonal, with most cases July through September
	* As well as being vector-borne, can also be transmitted by blood transfusion, solid organ transplantation, and vertically		* As well as being vector-borne, can also be transmitted by blood transfusion, solid organ transplantation, and vertically

	== Clinical Manifestations ==		== Clinical Manifestations ==

	* Incubation period of [[Usual incubation period::3 to 14 days]]		* Incubation period of [[Usual incubation period::3 to 14 days]], with range of [[Incubation period range::2 to 21 days]]
	* Up to 80% of infections are asymptomatic~~; of those with symptoms, [[fever]] is most common~~		* Up to 80% of infections are asymptomatic
			* Of the 20% with symptoms, [[fever]] is most common
			** Other common symptoms include headaches, generalized weakness, morbilliform or maculopapular rash (often occuring at defervescence), and myalgias
			** Less common symptoms include arthralgias, chills, eye pain, vomiting, diarrhea, and lymphadenopathy
			** Generally self-resolves within days to weeks with complete recovery, though fatigue may linger

			=== West Nile Neuroinvasive Disease ===
	* Some form of CNS disease develops in 1:150 people		* Some form of CNS disease develops in 1:150 people
	** [[Meningoencephalitis]]		* [[Meningoencephalitis]]
			** [[Meningitis]] with usual presentation (nuchal rigidity, headache, photophobia, phonophobia, fever)
	** [[Acute flaccid paralysis]]
			** [[Encephalitis]] with altered level of consciousness, lethargy, personality changes
	** 10% mortality, with about half of survivors having neuropsychiatric sequelae
			* [[Acute flaccid paralysis]] with acute onset and rapidly-progressive limb weakness
			** Usually asymmetry, areflexic/hyporeflexic, with preserved sensation
			** Usually but not always in the context of meningoencephalitis
			* Also may have nausea/vomiting, myalgias, arthralgias, chills, rash, ataxia, visual disturbance, tremors, myoclonus, bulbar dysfunction
			* Usually self-resolves over weeks to months, but half have neuropsychiatric sequelae (including function/cognitive dysfunction and paralysis)
			** 10% mortality

	== Differential Diagnosis ==		== Differential Diagnosis ==
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	* Supportive care		* Supportive care

			== Further Reading ==

			* West Nile Virus: Review of the Literature. ''JAMA.'' 2013;310(3):308–315. doi:[https://doi.org/10.1001/jama.2013.8042 10.1001/jama.2013.8042]

	[[Category:Flaviviridae]]		[[Category:Flaviviridae]]

Aidan at 10:44, 18 August 2020

2020-08-18T10:44:55Z

← Older revision		Revision as of 10:44, 18 August 2020
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	== ~~Diagnosis~~ ==		== Background ==

			* Single-stranded positive-sense enveloped virus in the family [[Flaviviridae]] and genus [[Flavivirus]]
⚫	* Serology
			* Essentially worldwide distribution
⚫	** Serum or CSF for IgM antibodies is the standard test; usually positive by 3 to 8 days, and persist for 2 to 3 months
			* Vector is [[Vector::mosquitoes]]
⚫	*** If submitted CSF, must also submit serum
			* Main reservoir is birds
⚫	** May cross-react with other flaviviruses
			* As well as being vector-borne, can also be transmitted by blood transfusion, solid organ transplantation, and vertically
⚫	** Can be seronegative if immunosuppressed (e.g. rituximab), therefore may need to do PCR

⚫	* PCR
			== Clinical Manifestations ==
⚫	** RNA virus, therefore needs reverse transcriptase step (RT-PCR)

⚫	** Can be done on serum, CSF, and tissue
			* Incubation period of [[Usual incubation period::3 to 14 days]]
⚫	* On MRI, may have a slight preference for thalamus
			* Up to 80% of infections are asymptomatic; of those with symptoms, [[fever]] is most common
			* Some form of CNS disease develops in 1:150 people
			** [[Meningoencephalitis]]
			** [[Acute flaccid paralysis]]
			** 10% mortality, with about half of survivors having neuropsychiatric sequelae

			== Differential Diagnosis ==

			* Other causes of [[meningitis]], [[encephalitis]], and [[acute flaccid paralysis]]

			==Diagnosis==

		⚫	*Serology
		⚫	**Serum or CSF for IgM antibodies is the standard test; usually positive by 3 to 8 days, and persist for 2 to 3 months
		⚫	***If submitted CSF, must also submit serum
		⚫	**May cross-react with other flaviviruses
		⚫	**Can be seronegative if immunosuppressed (e.g. rituximab), therefore may need to do PCR
		⚫	*PCR
		⚫	**RNA virus, therefore needs reverse transcriptase step (RT-PCR)
		⚫	**Can be done on serum, CSF, and tissue
		⚫	*On MRI, may have a slight preference for thalamus

			== Management ==

			* Supportive care

	[[Category:Flaviviridae]]		[[Category:Flaviviridae]]

Aidan: /* Diagnosis */

2019-08-16T10:29:51Z

Diagnosis

← Older revision		Revision as of 10:29, 16 August 2019
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	= Diagnosis =		== Diagnosis ==

	* Serology		* Serology

Aidan at 23:40, 14 August 2019

2019-08-14T23:40:20Z

@@ Line 1: / Line 1: @@
 * Serology
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 ** Can be done on serum, CSF, and tissue
 * On MRI, may have a slight preference for thalamus

Aidan: Aidan moved page RNA West Nile virus (WNV) to West Nile virus without leaving a redirect

2019-08-14T23:39:59Z

Aidan moved page RNA West Nile virus (WNV) to West Nile virus without leaving a redirect

← Older revision	Revision as of 23:39, 14 August 2019
(No difference)

Maintenance script: Imported from text file

2019-08-11T18:05:57Z

Imported from text file

New page

= West Nile virus (WNV) =

== Diagnosis ==

* Serology
** Serum or CSF for IgM antibodies is the standard test; usually positive by 3 to 8 days, and persist for 2 to 3 months
*** If submitted CSF, must also submit serum
** May cross-react with other flaviviruses
** Can be seronegative if immunosuppressed (e.g. rituximab), therefore may need to do PCR
* PCR
** RNA virus, therefore needs reverse transcriptase step (RT-PCR)
** Can be done on serum, CSF, and tissue
* On MRI, may have a slight preference for thalamus