Arbovirus

Source: Wikipedia, the free encyclopedia.
For the Bangladeshi rock band, see
Arbovirus encephalitis
.
Arbovirus infection
Infectious disease

Arbovirus is an informal name for any

superorder within the arthropods.[2] Arboviruses can affect both animals (including humans) and plants.[3] In humans, symptoms of arbovirus infection generally occur 3–15 days after exposure to the virus and last three or four days. The most common clinical features of infection are fever, headache, and malaise, but encephalitis and viral hemorrhagic fever may also occur.[4]

Signs and symptoms

The incubation period – the time between when infection occurs and when symptoms appear – varies from virus to virus, but is usually limited between 2 and 15 days for arboviruses.

flu-like illness, and are not indicative of a specific causative agent. These symptoms include fever, headache, malaise, rash and fatigue. Rarely, vomiting and hemorrhagic fever may occur. The central nervous system can also be affected by infection, as encephalitis and meningitis are sometimes observed.[7] Prognosis is good for most people, but is poor in those who develop severe symptoms, with up to a 20% mortality rate in this population depending on the virus. The very young, elderly, pregnant women, and people with immune deficiencies are more likely to develop severe symptoms.[citation needed
]

Arbovirus Disease(s) Incubation period Symptoms Duration of symptoms Complications Case fatality rate
Vector
(s) 		Primary host(s) Geographic distribution Does infection provide lifelong immunity?
Dengue virus Dengue fever 3–14 days Asymptomatic in most cases; fever, headache, rash, muscle, and joint pains 7–10 days Shock, internal bleeding, and organ damage <1% with treatment, 1–5% without; about 25% in severe cases Aedes mosquitoes, especially Aedes aegypti Humans Near the equator globally Varies[note 1]
Japanese encephalitis virus Japanese encephalitis 5–15 days Asymptomatic in most cases; fever, headache, fatigue, nausea, and vomiting Encephalitis, seizures, paralysis, coma, and long-term brain damage 20–30% in encephalitis cases Culex mosquitoes, especially Culex tritaeniorhynchus
Domestic pigs and wading birds
 Southeast and East Asia Yes
Rift Valley fever virus Rift Valley fever 2–6 days Fever, headache, myalgia and liver abnormalities 4–7 days Hemorrhagic fever, meningoencephalitis 1% in humans; in pregnant livestock, 100% fatality rate for fetuses Culex tritaeniorhynchus and Aedes vexans
Hipposideros abae
 		Eastern, Southern, and Western Africa Yes
Tick-borne encephalitis virus Tick-borne encephalitis 7–14 days Fever, headache, muscle pain, nausea, vomiting, meningitis, and encephalitis Paralysis and long-term brain damage 1–2% Ixodes scapularis, Ixodes ricinus, and Ixodes persulcatus Small rodents Eastern Europe and Southern Russia Yes
West Nile virus West Nile fever, encephalitis 2–15 days Asymptomatic in most cases; fever, headache, fatigue, nausea, vomiting, rash 3–6 days Swollen lymph nodes, meningitis, encephalitis,
acute flaccid paralysis
 3–15% in severe cases Culex mosquitoes Passerine birds North America, Europe, West and Central Asia, Oceania, and Africa Yes
Yellow fever virus Yellow fever 3–6 days Fever, headache, back pain, loss of appetite, nausea, and vomiting 3–4 days Jaundice, liver damage, gastrointestinal bleeding, recurring fever 3% in general; 20% in cases with severe complications Aedes mosquitoes, especially Aedes aegypti Primates Tropical and subtropical regions of South America and Africa Yes
  1. ^ Infection provides lifelong immunity to the specific serotype causing illness, but temporary immunity to other serotypes.

Cause

Transmission

Many female mosquitoes, like those of Aedes albopictus, require a vertebrate blood meal in order for their eggs to develop.[8]

Arboviruses maintain themselves in nature by going through a cycle between a

sandflies[10] and other arthropods that consume the blood of vertebrates for nutritious or developmental purposes.[11] Vertebrates which have their blood consumed act as the hosts, with each vector generally having an affinity for the blood of specific species, making those species the hosts.[12]

Transmission between the vector and the host occurs when the vector feeds on the blood of the vertebrate, wherein the virus that has established an infection in the salivary glands of the vector comes into contact with the host's blood.

virions present in the blood.[15] The abundance of virions in the host's blood allows the host to transmit the virus to other organisms if its blood is consumed by them. When uninfected vectors become infected from feeding, they are then capable of transmitting the virus to uninfected hosts, resuming amplification of virus populations. If viremia is not achieved in a vertebrate, the species can be called a "dead-end host", as the virus cannot be transmitted back to the vector.[16]

A flowchart showing the West Nile virus transmission cycle.

An example of this vector-host relationship can be observed in the transmission of the West Nile virus. Female mosquitoes of the genus Culex prefer to consume the blood of passerine birds, making them the hosts of the virus.[17] When these birds are infected, the virus amplifies, potentially infecting multiple mosquitoes that feed on its blood.[15] These infected mosquitoes may go on to further transmit the virus to more birds. If the mosquito is unable to find its preferred food source, it will choose another. Human blood is sometimes consumed, but since the West Nile virus does not replicate that well in mammals, humans are considered a dead-end host.[16][18]

In humans

Person-to-person transmission of arboviruses is not common, but can occur. Blood transfusions, organ transplantation, and the use of blood products can transmit arboviruses if the virus is present in the donor's blood or organs.[19][20][21] Because of this, blood and organs are often screened for viruses before being administered.[21][22] Rarely, vertical transmission, or mother-to-child transmission, has been observed in infected pregnant[23] and breastfeeding women.[24] Exposure to used needles may also transmit arboviruses if they have been used by an infected person or animal.[25] This puts intravenous drug users and healthcare workers at risk for infection in regions where the arbovirus may be spreading in human populations.[21][23]

Virology

Arboviruses are a polyphyletic group, belonging to various viral genera and therefore exhibiting different virologic characteristics.

Arbovirus Genome type Genome length Diameter Capsid shape Enveloped? Viral entry Replication site Viral shedding Infected cell(s) Genetic variability
African swine fever virus dsDNA 170-190 kilobases ~200 nm Icosahedral Yes Endocytosis Nucleus Budding
Endothelial cells and red and white blood cells
 22 genotypes
Chikungunya virus (CHIKV)
 +ssRNA 11.6 kilobases 60 - 70 nm Icosahedral Yes Membrane fusion Cell cytoplasm Budding
endothelial cells, primary fibroblasts and macrophages
 Three genotypes
Dengue virus +ssRNA ~11,000 nucleobases ~50 nm Icosahedral Yes Membrane fusion Cell cytoplasm Budding Langerhans and white blood cells Four serotypes
Japanese encephalitis virus
 +ssRNA ~11,000 nucleobases ~50 nm Icosahedral Yes Membrane fusion Cell cytoplasm Budding Five genotypes
Rift Valley fever virus
 -ssRNA Spherical Yes Cell cytoplasm Budding None[note 1]
Tick-borne encephalitis virus +ssRNA ~11,000 nucleobases 40-50 nm Icosahedral Yes Membrane fusion Cell cytoplasm Budding Neural cells Five genotypes
West Nile virus +ssRNA ~11,000 nucleobases (11-12 kilo bases) 45-50 nm Icosahedral Yes Membrane fusion Cell cytoplasm Budding
Yellow fever virus
 +ssRNA ~11,000 nucleobases 40-60 nm Icosahedral Yes Membrane fusion Cell cytoplasm Budding Hepatocytes and white blood cells
Zika virus +ssRNA 10794 nucleobases 40 nm Icosahedral Yes Membrane fusion Cell cytoplasm Budding
  1. ^ No significant distinct genetic populations exist due to the species having recent common ancestry.

Diagnosis

Preliminary diagnosis of arbovirus infection is usually based on clinical presentations of symptoms, places and dates of travel, activities, and epidemiological history of the location where infection occurred.[26] Definitive diagnosis is typically made in a laboratory by employing some combination of blood tests, particularly immunologic, serologic and/or virologic techniques such as ELISA,[26][27] complement fixation,[27] polymerase chain reaction,[27][28] neutralization test,[29] and hemagglutination-inhibition test.[30]

Classification

In the past, arboviruses were organized into one of four groups: A, B, C, and D. Group A denoted members of the genus Alphavirus,

biological classification. With the exception of the African swine fever virus, which belongs to the Asfarviridae family of viruses, all major clinically important arboviruses belong to one of the following four groups:[citation needed
]

Prevention

organochlorides (such as DDT) have been banned in many countries. Infertile male mosquitoes have been introduced in some areas in order to reduce the breeding rate of relevant mosquito species. Larvicides are also used worldwide in mosquito abatement programs. Temefos is a common mosquito larvicide.[36]

Tent made of mosquito netting

People can also reduce the risk of getting bitten by arthropods by employing personal protective measures such as sleeping under mosquito nets, wearing protective clothing, applying insect repellents such as permethrin and DEET to clothing and exposed skin, and (where possible) avoiding areas known to harbor high arthropod populations. Arboviral encephalitis can be prevented in two major ways: personal protective measures and public health measures to reduce the population of infected mosquitoes. Personal measures include reducing time outdoors particularly in early evening hours, wearing long pants and long sleeved shirts and applying mosquito repellent to exposed skin areas. Public health measures often require spraying of insecticides to kill juvenile (larvae) and adult mosquitoes.[37]

Vaccination

Vaccines are available for the following arboviral diseases:

  • Japanese encephalitis[38]
  • Yellow fever[39]
  • Tick-borne encephalitis[40]
  • Rift Valley Fever (only veterinary use)[41]

Vaccines are in development for the following arboviral diseases:

Treatment

Because the arboviral encephalitides are viral diseases, antibiotics are not an effective form of treatment and no effective antiviral drugs have yet been discovered. Treatment is supportive, attempting to deal with problems such as swelling of the brain, loss of the automatic breathing activity of the brain and other treatable complications like bacterial pneumonia.[1]

The WHO caution against the use of aspirin and ibuprofen as they can increase the risk of bleeding.[47][48]

Epidemiology

Most arboviruses are located in tropical areas, however as a group they have a global distribution. The warm climate conditions found in tropical areas allows for year-round transmission by the arthropod vectors. Other important factors determining geographic distribution of arthropod vectors include rainfall, humidity, and vegetation.[49]

Mapping methods such as GIS and GPS have allowed for spatial and temporal analyses of arboviruses. Tagging cases or breeding sites geographically has allowed for deeper examination of vector transmission.[50]

To see the epidemiology of specific arboviruses, the following resources hold maps, fact sheets, and reports on arboviruses and arboviral epidemics.

Resource Description Link
World Health Organization The WHO compiles studies and maps of the distribution, risk factors, and prevention of specific viruses.

The WHO also hosts DengueNet, a database which can be queried about Dengue cases.

http://www.who.int/en/

[1]

CDC ArboNet Dynamic Map This interactive map is created by USGS using data from the CDC ArboNET. It provides distribution maps of cases in humans and vectors in the United States. https://web.archive.org/web/20161215234534/http://diseasemaps.usgs.gov/mapviewer/
Center for Disease Control ArboCatalog The ArboCatalog documents probable arboviruses recorded by the Center for Disease Control, and provides detailed information about the viruses. https://wwwn.cdc.gov/Arbocat/Default.aspx

History

Year Event
1800s Dengue fever epidemics occur globally
1898–1914 First large scale effort to prevent arbovirus infection
takes place in Florida, Havana, and the Panama Canal Zone
1901 First arbovirus, the yellow fever virus, is discovered
1906 Dengue fever transmission is discovered
1936 Tick-borne encephalitis virus is discovered
1937 Yellow fever vaccine is invented
1937 West Nile virus is discovered
1950s Japanese encephalitis vaccines are invented
1980s Insecticide treated mosquito nets are developed
1999 West Nile virus reaches the Western Hemisphere
Late 1900s Dengue fever spreads globally

Arboviruses were not known to exist until the

mosquitoes instead of human contact,[51] a reality that was verified by Major Walter Reed in 1901.[52] The primary vector, Aedes aegypti, had spread globally from the 15th to the 19th centuries as a result of globalization and the slave trade.[53] This geographic spreading caused dengue fever epidemics throughout the 18th and 19th centuries,[54] and later, in 1906, transmission by the Aedes mosquitoes was confirmed, making yellow fever and dengue fever the first two diseases known to be caused by viruses.[55]

global warming,[61] and continues to cause at least 50 million infections per year, making Dengue fever the most common and clinically important arboviral disease.[62][63]

caustic soda, to be used throughout the Canal Zone.[66] The combined implementation of these sanitation measures led to a dramatic decline in the number of workers dying and the eventual eradication of yellow fever in the Canal Zone as well as the containment of malaria during the 10-year construction period. Because of the success of these methods at preventing disease, they were adopted and improved upon in other regions of the world.[64][67]

See also

References

  1. ^ a b "CDC Information on Arboviral Encephalitides". Archived from the original on January 27, 2007. Retrieved 2007-02-07.
  2. S2CID 18713459
    .
  3. ^ "Plant arboviruses: major threats to food security". Microbiology Society. Retrieved 20 May 2022.
  4. ^ Stephen J. Schueler; John H. Beckett; D. Scott Gettings (2 April 2008). "Arbovirus Infection Symptoms". freeMD. Archived from the original on 8 September 2008. Retrieved 22 June 2013.
  5. S2CID 13074756
    .
  6. PMID 20403310
    .
  7. S2CID 30778922
    .
  8. ^ "Human blood contains the secret ingredient for mosquito eggs". May 4, 2011. Archived from the original on June 30, 2013. Retrieved 6 April 2013.
  9. OCLC 207797812
    .
  10. PMID 20403307
    .
  11. ^ "Life cycle of Hard Ticks that Spread Disease". Centers for Disease Control and Prevention (CDC). 26 July 2012. Retrieved 26 June 2013.
  12. PMID 16223950
    .
  13. S2CID 32742815
    .
  14. PMID 18000543
    .
  15. ^
    PMID 16358422
    .
  16. ^
    S2CID 28937401
    .
  17. S2CID 20531226
    .
  18. PMID 22693557
    .
  19. PMID 18832256
    .
  20. S2CID 19419227
    .
  21. ^
    PMID 19392949
    .
  22. PMID 15071426
    .
  23. ^
    PMID 20130380
    .
  24. PMID 12375687
    .
  25. S2CID 25170132
    .
  26. ^ a b "Arboviral Diagnostic Testing". Centers for Disease Control and Prevention (CDC). Retrieved April 17, 2013.
  27. ^ a b c "Arbovirus Antibodies Test". Medical Health Tests. March 27, 2012. Retrieved April 17, 2013.
  28. PMID 11337046
    .
  29. PMID 4216288
    .
  30. PMID 5165837
    .
  31. PMID 4128825
    .
  32. PMID 1155702
    .
  33. S2CID 625707
    .
  34. S2CID 39810753
    .
  35. ISBN 978-0849343872
    . Retrieved 16 June 2013.
  36. PMID 7403901
    .
  37. ^ "Preventing Mosquito Bites". North Carolina Department of Health and Human Services.
  38. ^ "Japanese Encephalitis Vaccine, What You Need to Know" (PDF). Centers for Disease Control and Prevention (CDC). December 7, 2011. Archived from the original (PDF) on 9 March 2013. Retrieved 20 March 2013.
  39. ^ "Yellow Fever Vaccine, What You Need to Know" (PDF). Centers for Disease Control and Prevention (CDC). March 30, 2011. Retrieved 20 March 2013.
  40. ^ "Tick-borne Encephalitis". World Health Organization (WHO). Archived from the original on October 4, 2014. Retrieved 5 November 2019.
  41. ^
    S2CID 201805546
    .
  42. ^ "Database Access - UNSW Library".
  43. ^ "Dengue fever vaccine program". Global Vaccines. Archived from the original on 9 January 2013. Retrieved 20 March 2013.
  44. PMID 22222869
    .
  45. ^ Young, S. (August 12, 2012). "Few Options in the West Nile Fight". MIT Technology Review. Archived from the original on 22 October 2012. Retrieved 20 March 2013.
  46. PMID 29259782
    .
  47. ^ "Dengue and severe dengue -section What is the treatment for dengue?". WHO. 24 October 2019.
  48. PMID 31701855
    .
  49. PMID 12234522
    .
  50. S2CID 29858335
    .
  51. PMID 16435764
    .
  52. PMID 18013904
    .
  53. PMID 22494122
    .
  54. PMID 9665979
    .
  55. PMID 2224837
    .
  56. PMID 16559270
    .
  57. ISBN 978-0615827735
    .
  58. doi:10.4269/ajtmh.1940.s1-20.471
    .
  59. PMID 13084817
    .
  60. ^ Sun, L. H. (13 September 2012). "West Nile epidemic on track to be deadliest ever: CDC". The Washington Post. Archived from the original on 24 June 2013. Retrieved 19 June 2013.
  61. S2CID 215154729
    .
  62. S2CID 4232236
    .
  63. PMID 21079655
    .
  64. ^ a b "Tropical Diseases and the Construction of the Panama Canal, 1904–1914". Contagion: Historical Views of Diseases and Epidemics. Retrieved 19 June 2013.
  65. ^ "Malaria: The Panama Canal". Centers for Disease Control and Prevention (CDC). 8 February 2010. Retrieved 19 June 2013.
  66. PMID 12862098
    .
  67. ^ "Yellow Fever and Malaria in the Canal". PBS. American Experience. Archived from the original on 23 March 2017. Retrieved 19 June 2013.

External links

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