West Nile virus: Difference between revisions

Latest revision as of 02:45, 11 December 2024

West Nile virus (WNV) is a single-stranded RNA virus that causes West Nile fever. It is a member of the Flavivirus genus and belongs to the family Flaviviridae. The virus is primarily transmitted to humans through the bite of an infected mosquito, most commonly the Culex species.

Virology[edit]

File:Genome of the West Nile Virus.gif

Genome of the West Nile Virus

West Nile virus is an enveloped virus with a single-stranded, positive-sense RNA genome. The genome is approximately 11,000 nucleotides long and encodes a single polyprotein that is cleaved into three structural proteins (C, prM, and E) and seven nonstructural proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5).

The virus is closely related to other flaviviruses such as Dengue virus, Zika virus, and Yellow fever virus.

Transmission[edit]

WNV is primarily transmitted by mosquitoes, with birds serving as the main reservoir hosts. Humans and other mammals are considered dead-end hosts, as they do not develop high enough levels of viremia to infect mosquitoes. The virus can also be transmitted through blood transfusions, organ transplants, and from mother to child during pregnancy, delivery, or breastfeeding.

Epidemiology[edit]

West Nile virus was first identified in the West Nile district of Uganda in 1937. Since then, it has spread to many parts of the world, including Africa, Europe, the Middle East, North America, and West Asia. The first major outbreak in the United States occurred in 1999 in New York City.

Clinical Features[edit]

Most people infected with WNV are asymptomatic. Approximately 20% of infected individuals develop West Nile fever, which is characterized by fever, headache, tiredness, body aches, nausea, vomiting, and sometimes swollen lymph glands or a skin rash. Less than 1% of infected individuals develop severe neurological disease, such as encephalitis or meningitis, which can be fatal.

Diagnosis[edit]

Diagnosis of WNV infection is typically based on clinical symptoms and confirmed by laboratory testing. Serological tests, such as the detection of IgM antibodies in serum or cerebrospinal fluid, are commonly used. Reverse transcription polymerase chain reaction (RT-PCR) can also be used to detect viral RNA.

Prevention and Control[edit]

Preventive measures focus on reducing mosquito exposure. This includes using insect repellent, wearing long sleeves and pants, and eliminating standing water where mosquitoes breed. Public health efforts also include mosquito control programs and surveillance of bird populations.

Also see[edit]

Template:Flaviviridae

@@ Line 1: / Line 1: @@
-= West Nile Virus =
+{{Infobox virus
+| name = West Nile virus
+| image = West Nile Virus Image.jpg
+| image_caption = Electron micrograph of the West Nile virus
+| virus_group = iv
+| familia = [[Flaviviridae]]
+| genus = [[Flavivirus]]
+| species = West Nile virus
+}}
-== Introduction ==
+'''West Nile virus''' (WNV) is a single-stranded RNA virus that causes [[West Nile fever]]. It is a member of the [[Flavivirus]] genus and belongs to the family [[Flaviviridae]]. The virus is primarily transmitted to humans through the bite of an infected [[mosquito]], most commonly the [[Culex]] species.
-West Nile virus is a flavivirus primarily transmitted to humans through the bite of an infected mosquito. It is the causative agent of West Nile encephalitis, a condition that can lead to serious neurological disease.
-<youtube>
+== Virology ==
-title='''{{PAGENAME}}'''
+[[File:Genome of the West Nile Virus.gif|thumb|Genome of the West Nile Virus]]
-movie_url=http://www.youtube.com/v/9QplnB50L-w
+West Nile virus is an [[enveloped virus]] with a single-stranded, positive-sense RNA genome. The genome is approximately 11,000 nucleotides long and encodes a single polyprotein that is cleaved into three structural proteins (C, prM, and E) and seven nonstructural proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5).
-&rel=1
-embed_source_url=http://www.youtube.com/v/9QplnB50L-w
-&rel=1
-wrap = yes
-width=750
-height=600
-</youtube>
-== Discovery and History ==
+The virus is closely related to other flaviviruses such as [[Dengue virus]], [[Zika virus]], and [[Yellow fever virus]].
-The virus was first identified in 1937 in the West Nile district of Uganda. Since then, it has been detected in various regions around the world, with significant outbreaks occurring in Africa, Europe, the Middle East, North America, and West Asia.
 == Transmission ==
-West Nile virus is primarily transmitted through the bite of infected mosquitoes, particularly those of the ''Culex'' species. Birds are the natural hosts of the virus, with mosquitoes becoming infected when they feed on infected birds.
+WNV is primarily transmitted by mosquitoes, with birds serving as the main reservoir hosts. Humans and other mammals are considered dead-end hosts, as they do not develop high enough levels of viremia to infect mosquitoes. The virus can also be transmitted through blood transfusions, organ transplants, and from mother to child during pregnancy, delivery, or breastfeeding.
-[[File:Culex pipiens diagram en.svg|thumb|600px|Culex mosquito, a primary vector of West Nile virus.]]
+== Epidemiology ==
+West Nile virus was first identified in the West Nile district of Uganda in 1937. Since then, it has spread to many parts of the world, including Africa, Europe, the Middle East, North America, and West Asia. The first major outbreak in the United States occurred in 1999 in New York City.
-== Symptoms and Clinical Presentation ==
+== Clinical Features ==
-While most infections are asymptomatic, West Nile virus can cause a range of symptoms, including:
+Most people infected with WNV are asymptomatic. Approximately 20% of infected individuals develop West Nile fever, which is characterized by fever, headache, tiredness, body aches, nausea, vomiting, and sometimes swollen lymph glands or a skin rash. Less than 1% of infected individuals develop severe neurological disease, such as encephalitis or meningitis, which can be fatal.
-* Mild illness (West Nile fever) - fever, headache, body aches, skin rash, swollen lymph glands.
-* Severe illness (West Nile encephalitis or meningitis) - headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, and paralysis.
 == Diagnosis ==
-Diagnosis is typically based on symptoms and confirmed with laboratory tests such as:
+Diagnosis of WNV infection is typically based on clinical symptoms and confirmed by laboratory testing. Serological tests, such as the detection of IgM antibodies in serum or cerebrospinal fluid, are commonly used. Reverse transcription polymerase chain reaction (RT-PCR) can also be used to detect viral RNA.
-* Serological tests to detect virus-specific antibodies.
-* Polymerase chain reaction (PCR) testing to identify viral RNA.
 == Prevention and Control ==
-Preventive measures include:
+Preventive measures focus on reducing mosquito exposure. This includes using insect repellent, wearing long sleeves and pants, and eliminating standing water where mosquitoes breed. Public health efforts also include mosquito control programs and surveillance of bird populations.
-* Mosquito control programs.
-* Use of insect repellent.
-* Protective clothing.
-* Avoidance of outdoor activities at peak mosquito times.
-* Vaccination for horses (no human vaccine is currently available).
-== Treatment ==
+== Also see ==
-There is no specific treatment for West Nile virus infection. Management of symptoms includes supportive care, such as pain relievers and hydration. In severe cases, hospitalization may be necessary for intensive supportive therapy.
+* [[Flavivirus]]
+* [[Mosquito-borne diseases]]
+* [[Encephalitis]]
+* [[Zika virus]]
+* [[Dengue fever]]
-== Epidemiology and Public Health ==
+{{Flaviviridae}}
-West Nile virus is a significant public health concern due to its potential for causing large outbreaks and severe neurological disease. Surveillance and reporting are crucial for monitoring virus activity and initiating control measures.
+{{Viral diseases}}
-== External Links ==
-* [Link to the Centers for Disease Control and Prevention (CDC) page on West Nile virus]
-* [Link to a World Health Organization (WHO) report on West Nile virus and public health]
-== References ==
-<references/>
 [[Category:Flaviviruses]]
 [[Category:Viral diseases]]
 [[Category:Zoonoses]]
-{{Stub}}