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This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (October 2008) |
| Bunyaviridae |
|
| Isolated male patient diagnosed with Crimean-Congo hemorrhagic fever (C-CHF) |
| Virus classification |
| Group: |
Group V ((-)ssRNA) |
| Order: |
Unassigned |
| Family: |
Bunyaviridae |
| Genus |
|
Hantavirus
Nairovirus
Orthobunyavirus
Phlebovirus
Tospovirus
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Bunyaviridae is a family of negative-stranded, enveloped RNA viruses. Though generally found in arthropods or rodents, certain viruses in this family occasionally infect humans. Some of them also infect plants.[1]
Bunyaviridae are vector-borne viruses. With the exception of Hantaviruses, transmission occurs via an arthropod vector (mosquitos, tick, or sandfly). Hantaviruses are transmitted through contact with deer mice feces. Incidence of infection is closely linked to vector activity, for example, mosquito-borne viruses are more common in the summer.[1]
Human infections with certain Bunyaviridae, such as Crimean-Congo hemorrhagic fever virus, are associated with high levels of morbidity and mortality, consequently handling of these viruses must occur with a Biosafety level 4 laboratory. They are also the cause of severe fever with thrombocytopenia syndrome.[2]
Hanta virus or Hantavirus Hemorrhagic fever, common in Korea, Scandinavia, Russia, and western North America, is associated with high fever, lung edema and pulmonary failure. Mortality is around 55%.
The antibody reaction plays an important role in decreasing levels of viremia.
Contents
- 1 Virology
- 1.1 Classification
- 1.2 Structure
- 1.3 Genome
- 1.4 Replication
- 2 Diseases in Humans
- 3 References
- 4 External links
Virology
Classification
There are currently about 330 viruses recognised in this family.
The family Bunyaviridae contains the genera:
- Genus Hantavirus; type species: Hantaan virus
- Genus Nairovirus; type species: Dugbe virus
- Genus Orthobunyavirus; type species: Bunyamwera virus
- Genus Phlebovirus; type species: Rift Valley fever virus
- Genus Tospovirus; type species: Tomato spotted wilt virus
There are a number of viruses that have not yet been placed in a genus: these include Gan Gan virus, Maprik virus, Mapputta virus and Trubanaman virus.
A new genus - as yet unnamed - has been proposed based on isolates from phantom midges.[3]
Two additional viruses may lie outside the previously defined taxa: Ferak virus (FERV) and Jonchet virus (JONV).[4]
Structure
Bunyavirus morphology is somewhat similar to that of the Paramyxoviridae family; Bunyaviridae form enveloped, spherical virions with diameters of 90–100 nm. These viruses contain no matrix proteins.
Genome
Bunyaviridae have tripartite genomes consisting of a large (L), medium (M), and small (S) RNA segment. These RNA segments are single-stranded, and exist in a helical formation within the virion. Besides, they exhibit a pseudo-circular structure due to each segment's complementary ends. The L segment encodes the RNA Dependent RNA-polymerase, necessary for viral RNA replication and mRNA synthesis. The M segment encodes the viral glycoproteins, which project from the viral surface and aid the virus in attaching to and entering the host cell. The S segment encodes the nucleocapsid protein (N).
The L and M segment are negative sense. For the Genera of Phlebovirus and Tospovirus, the S segment is ambisense. Ambisense means that some of the genes on the RNA strand are negative sense and others are positive sense. The S segment codes for the viral nucleoprotein (N) in the negative sense and a nonstructural (NSs) protein in ambisense.
Total genome size ranges from 10.5 to 22.7 kbp.[5]
Replication
This ambisense arrangement requires two rounds of transcription to be carried out. First the negative sense RNA is transcribed to produce mRNA and a full length replicative intermediate. From this intermediate a subgenomic mRNA encoding the small segment nonstructural protein is produced while the polymerase produced following the first round of transcription can now replicate the full length RNA to produce viral genomes.
Bunyavirus RNA replicates in the cytoplasm, while the viral proteins transit through the ER and Golgi apparatus. Mature virions bud from the Golgi apparatus into vesicles which are transported to the cell surface.
Diseases in Humans
Bunyaviruses that cause disease in humans include:
- California encephalitis virus
- Hantavirus
- Crimean-Congo hemorrhagic fever
- Rift Valley fever
- Bwamba Fever
- severe fever with thrombocytopenia syndrome
Bunyaviruses have segmented genomes, making them capable of rapid recombination and increasing the risk of outbreak.[6] Bunyaviridae are transmitted by hematophagous arthropods including mosquitoes, midges, flies, and ticks. The viral incubation period is about 48 hours. Symptomatic infection typically causes nonspecific flulike symptoms with fever lasting for about three days. Because of their nonspecific symptoms, Bunyavirus infections are frequently mistaken for other illnesses. For example, Bwamba fever is often mistaken for malaria.[7]
References
- ^ a b Plyusnin, A; Elliott, RM, ed. (2011). Bunyaviridae: Molecular and Cellular Biology. Caister Academic Press. ISBN 978-1-904455-90-5.
- ^ Yu XJ, Liang MF, Zhang SY; et al. (April 2011). "Fever with thrombocytopenia associated with a novel bunyavirus in China". N. Engl. J. Med. 364 (16): 1523–32. doi:10.1056/NEJMoa1010095. PMC 3113718. PMID 21410387.
- ^ Ballinger, MJ; Bruenn, JA; Hay, J; Czechowski, D; Taylor, DJ (2014). "Discovery and evolution of bunyavirids in arctic phantom midges and ancient bunyavirid-like sequences in insect genomes". J Virol.
- ^ Marklewitz, M; Zirkel, F; Kurth, A; Drosten, C; Junglen, S (2015). "Evolutionary and phenotypic analysis of live virus isolates suggests arthropod origin of a pathogenic RNA virus family". Proc Natl Acad Sci USA 112 (24): 7536–41. doi:10.1073/pnas.1502036112.
- ^ "00.011. Bunyaviridae". ICTVdB—The Universal Virus Database, version 4. 2006. Retrieved 2009-01-01.
- ^ Horne, Kate McElroy; Vanlandingham, Dana L. (2014-11-13). "Bunyavirus-Vector Interactions". Viruses 6 (11): 4373–4397. doi:10.3390/v6114373. ISSN 1999-4915. PMC 4246228. PMID 25402172. Retrieved 2015-05-19.
- ^ PhD, Patrick R. Murray; PhD, Ken S. Rosenthal; MD, Michael A. Pfaller (2008-12-24). Medical Microbiology, 6e (6 ed.). Philadelphia: Mosby. ISBN 9780323054706.
External links
- Viralzone: Bunyaviridae
- ICTVdb Index of Viruses—Bunyaviridae
- The Big Picture Book of Viruses: Bunyaviridae
- Bunyaviridae Genomes—database search results from the Viral Bioinformatics Resource Center
- Virus Pathogen Database and Analysis Resource (ViPR): Bunyaviridae
- "Bunyaviridae". NCBI Taxonomy Browser. 11571.
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Zoonotic viral diseases (A80–B34, 042–079)
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| Arthropod-borne |
| Mosquito-borne |
| Bunyaviridae |
- Arbovirus encephalitides: La Crosse encephalitis
- California encephalitis
- Viral hemorrhagic fevers: Rift Valley fever
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| Flaviviridae |
- Arbovirus encephalitides: Japanese encephalitis
- Australian encephalitis
- Saint Louis encephalitis
- West Nile fever
- Viral hemorrhagic fevers: Dengue fever
- Yellow fever
- ZIKV
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| Togaviridae |
- Arbovirus encephalitides: Eastern equine encephalomyelitis
- Western equine encephalomyelitis
- Venezuelan equine encephalomyelitis
- Chikungunya
- O'Nyong-nyong fever
- Ross River fever
- Semliki Forest virus
- Sindbis fever
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| Reoviridae |
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| Tick-borne |
| Bunyaviridae |
- Viral hemorrhagic fevers: Crimean–Congo hemorrhagic fever
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| Flaviviridae |
- Arbovirus encephalitides: Tick-borne encephalitis
- Powassan encephalitis
- Viral hemorrhagic fevers: Omsk hemorrhagic fever
- Kyasanur forest disease
- Langat virus (LGTV)
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| Reoviridae |
- Colorado tick fever
- Kemerovo tickborne viral fever
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| Mammal-borne |
| Rodent-borne |
| Arenaviridae |
- Viral hemorrhagic fevers: Lassa fever
- Venezuelan hemorrhagic fever
- Argentine hemorrhagic fever
- Brazilian hemorrhagic fever
- Bolivian hemorrhagic fever
- LUJV
- CHPV
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| Bunyaviridae |
- Hemorrhagic fever with renal syndrome
- Hantavirus pulmonary syndrome
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|
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| Bat-borne |
| Filoviridae |
- Viral hemorrhagic fevers: Ebola virus disease
- BDBV
- EBOV
- SUDV
- TAFV
- Marburg virus disease
- MARV
- RAVV
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| Rhabdoviridae |
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| Paramyxoviridae |
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| Primate-borne |
| Herpesviridae |
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| Retroviridae |
- Simian foamy virus
- HTLV-1
- HTLV-2
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| Poxviridae |
- Tanapox
- Yaba monkey tumor virus
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| Multiple vectors |
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Index of viral disease
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| Description |
|
|
| Disease |
- Systemic
- Cutaneous
- Zoster
- Human papillomavirus
- Zoonotic
- Symptoms and signs
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| Treatment |
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