Tahyna virus

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Tahyna virus
Virus classification
Group:
Group V ((−)ssRNA)
Order:
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Genus:
Species:
Tahyna virus

Tahyna virus ("TAHV") is a viral pathogen of humans classified in the California encephalitis virus (CEV) serogroup of the Orthobunyavirus family in the order Bunyavirales, which is endemic to Europe, Asia, Africa [1] [2] and possibly China. [3]

Contents

TAHV is maintained in an enzootic life cycle involving several species of mosquito vectors, with hares, rabbits, hedgehogs, and rodents serving as amplifying hosts. [1]

History

In 1958 a virus transmitted by a mosquito was isolated in the Slovak village of Ťahyňa. The virus was unknown in Europe and was found to belong to the California group and eventually found to occur in most European countries. In human patients, infection with the Tahyna virus appears with influenza-like symptoms. In some cases, meningoencephalitis and atypical pneumonia were observed but no fatal cases have been reported. There are no significant clinical differences between Tahnya and Inkoo viruses. [4]

Signs and symptoms

TAHV causes a non-fatal flu-like illness in humans and is sometimes called Valtice fever. [1] Human TAHV infections generally occur in summer and early fall, with symptoms of fever, headache, malaise, conjunctivitis, pharyngitis, and nausea. The incubation period of the virus lasts about 3 to 7 days. [4] TAHV disease can progress to involve the central nervous system, but fatalities have not been reported. Human infections are common in endemic areas, with neutralizing antibodies present in 60 to 80% of the elderly population. [1]

Diagnosis

The diagnosis of orthobunyaviruses is based on serology, either as a rise in IgG-antibody titers, or the presence of IgM antibodies. RT-PCR methods are under development to detect viral RNA in cerebrospinal fluid samples of patients with encephalitis. [5]

Genetics

Genetic analysis of three complete TAHV genomes has demonstrated a high level of conservation (99%) at the nucleotide and amino acid level, despite the fact that the viruses were collected from temporally distinct regions spanning a 10 to 26 year period. This level of genetic stability is remarkable and suggests a strong environmental pressure to maintain specific genetic compositions. [1]

Structure

These enveloped viruses have a three-segmented negative-strand RNA genome. [5] of approximately 13 kb in total length. The three segments are designated by their size, small (S), medium (M), and large (L) and are complexed with nucleoprotein to form three separate nucleocapsids. The 3' and 5' untranslated regions (UTR) are complementary and highly conserved. The S segment encodes two proteins: the nucleoprotein (N) and a non-structural protein (NSs) which inhibits transcription via inhibiting host cell RNA polymerase II resulting in decreased interferon (INF) induction. The M segment encodes a single polyprotein (M polyprotein) that is post-translationally processed into two surface glycoproteins (GNand GC) which are the targets of neutralizing antibodies, and a nonstructural protein, NSM. The L segment encodes a RNA-dependent RNA polymerase. [1]

Related Research Articles

<i>Flaviviridae</i> family of viruses

Flaviviridae is a family of viruses. Humans and other mammals serve as natural hosts. They are primarily spread through arthropod vectors. The family gets its name from the yellow fever virus, the type virus of Flaviviridae; flavus is Latin for "yellow", and yellow fever in turn was named because of its propensity to cause jaundice in victims. Currently, over 100 species are in this family, divided among four genera. Diseases associated with this family include: hepatitis (hepaciviruses), hemorrhagic syndromes, fatal mucosal disease (pestiviruses), hemorrhagic fever, encephalitis, and the birth defect microcephaly (flaviviruses).

<i>Orthohantavirus</i> Genus of viruses

Orthohantavirus is a genus of single-stranded, enveloped, negative-sense RNA viruses in the family Hantaviridae of the order Bunyavirales. Members of this genus may be called orthohantaviruses or simply hantaviruses. They normally cause infection in rodents, but do not cause disease in them. Humans may become infected with hantaviruses through contact with rodent urine, saliva, or feces. Some strains cause potentially fatal diseases in humans, such as hantavirus hemorrhagic fever with renal syndrome (HFRS), or hantavirus pulmonary syndrome (HPS), also known as hantavirus cardiopulmonary syndrome (HCPS), while others have not been associated with known human disease. HPS (HCPS) is a "rare respiratory illness associated with the inhalation of aerosolized rodent excreta contaminated by hantavirus particles."

<i>Flavivirus</i> Genus of viruses

Flavivirus is a genus of viruses in the family Flaviviridae. This genus includes the West Nile virus, dengue virus, tick-borne encephalitis virus, yellow fever virus, Zika virus and several other viruses which may cause encephalitis, as well as insect-specific flaviviruses (ISFs) such as cell fusing agent virus (CFAV), Palm Creek virus (PCV), and Parramatta River virus (PaRV).

Arbovirus Virus transmitted by arthropod vectors

Arbovirus is an informal name used to refer to any viruses that are transmitted by arthropod vectors. The word arbovirus is an acronym. The word tibovirus is sometimes used to more specifically describe viruses transmitted by ticks, a superorder within the arthropods. Arboviruses can affect both animals and plants. 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 hemorrhagic fever may also occur.

Rabies virus species of virus

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<i>Bunyavirales</i> Order of negative-sense single-stranded RNA viruses

Bunyavirales is an order of negative-sense single-stranded RNA viruses. It is the only order in the class Ellioviricetes. It was formerly known as Bunyaviridae family of viruses. The name Bunyavirales derives from Bunyamwera, where the original type species Bunyamwera orthobunyavirus was first discovered. Ellioviricetes is named in honor of late virologist Richard M. Elliott for his early work on bunyaviruses.

Bwamba orthobunyavirus (BWAV) belongs to the genus Orthobunyavirus and the order Bunyavirales RNA viruses. BWAV is present in large parts of Africa, endemic in Mozambique, Tanzania and Uganda. It is transmitted to humans through mosquito bites and results in a brief benign generalised infection with headache, skin rash, diarrhea and joint pain and lasts 4–5 days. The animal reservoir of the virus includes birds, monkeys and donkeys.

Oropouche fever Human disease

Oropouche fever is a tropical viral infection transmitted by biting midges and mosquitoes from the blood of sloths to humans. This disease is named after the region where it was first discovered and isolated at the Trinidad Regional Virus Laboratory in 1955 by the Oropouche River in Trinidad and Tobago. Oropouche fever is caused by a specific arbovirus, the Oropouche virus (OROV), of the Bunyaviridae family.

<i>Alphavirus</i> Genus of Viruses

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Viral encephalitis is inflammation of the brain parenchyma, called encephalitis, by a virus. The different forms of viral encephalitis are called viral encephalitides. It is the most common type of encephalitis and often occurs with viral meningitis. Encephalitic viruses first cause infection and replicate outside of the central nervous system (CNS), most reaching the CNS through the circulatory system and a minority from nerve endings toward the CNS. Once in the brain, the virus and the host's inflammatory response disrupt neural function, leading to illness and complications, many of which frequently are neurological in nature, such as impaired motor skills and altered behavior.

<i>Thogotovirus</i> genus of viruses

Thogotovirus is a genus of enveloped RNA viruses, one of seven genera in the virus family Orthomyxoviridae. Their single-stranded, negative-sense RNA genome has six or seven segments. Thogotoviruses are distinguished from most other orthomyxoviruses by being arboviruses – viruses that are transmitted by arthropods, in this case usually ticks. Thogotoviruses can replicate in both tick cells and vertebrate cells; one subtype has also been isolated from mosquitoes. A consequence of being transmitted by blood-sucking vectors is that the virus must spread systemically in the vertebrate host – unlike influenza viruses, which are transmitted by respiratory droplets and are usually confined to the respiratory system.

<i>Orthobunyavirus</i> genus of viruses

Orthobunyavirus is a genus of the Peribunyaviridae family in the order Bunyavirales. There are currently ~170 viruses recognised in this genus. These have been assembled into 49 species and 20 serogroups.

Bunyamwera orthobunyavirus (BUNV) is a negative-sense, single-stranded enveloped RNA virus. It is the type species of the Orthobunyavirus genus, in the Bunyavirales order.

Batai virus (BATV) is a RNA virus belonging to order Bunyavirales, genus Orthobunyavirus.

Cache Valley virus (CVV) is a member of the order Bunyavirales, genus Orthobunyavirus, and serogroup Bunyamwera, which was first isolated in 1956 from Culiseta inornata mosquitos collected in Utah's Cache Valley. CVV is an enveloped arbovirus, nominally 80–120 nm in diameter, whose genome is composed of three single-stranded, negative-sense RNA segments. The large segment of related bunyaviruses is approximately 6800 bases in length and encodes a probable viral polymerase. The middle CVV segment has a 4463-nucleotide sequence and the smallest segment encodes for the nucleocapsid, and a second non-structural protein. CVV has been known to cause outbreaks of spontaneous abortion and congenital malformations in ruminants such as sheep and cattle. CVV rarely infects humans, but when they are infected it has caused encephalitis and multiorgan failure.

Jamestown Canyon encephalitis is an infectious disease caused by the Jamestown Canyon virus, an orthobunyavirus of the California serogroup. It is mainly spread during the summer by different mosquito species in the United States and Canada.

Spondweni virus is an arbovirus, or arthropod-borne virus, which is a member of the family Flaviviridae and the genus Flavivirus. It is part of the Spondweni serogroup which consists of the Sponweni virus and the Zika virus (ZIKV). The Spondweni virus was first isolated in Nigeria in 1952, and ever since, SPONV transmission and activity have been reported throughout Africa. Its primary vector of transmission is the sylvatic mosquito Aedes circumluteolus, though it has been isolated from several different types of mosquito. Transmission of the virus into humans can lead to a viral infection known as Spondweni fever, with symptoms ranging from headache and nausea to myalgia and arthralgia. However, SPONV is phylogenetically close to the ZIKV, it is commonly misdiagnosed as ZIKV along with other viral illnesses.

<i>West Nile virus</i> Species of virus

West Nile virus (WNV) is a single-stranded RNA virus that causes West Nile fever. It is a member of the family Flaviviridae, specifically from the genus Flavivirus, which also contains the Zika virus, dengue virus, and yellow fever virus. West Nile virus is primarily transmitted by mosquitoes, mostly species of Culex. The primary hosts of WNV are birds, so that the virus remains within a "bird–mosquito–bird" transmission cycle.

Yokose virus (YOKV) is in the genus Flavivirus of the family Flaviviridae. Flaviviridae are often found in arthropods, such as mosquitoes and ticks, and may also infect humans. The genus Flavivirus includes over 50 known viruses, including Yellow Fever, West Nile Virus, Zika Virus, and Japanese Encephalitis. Yokose virus is a new member of the Flavivirus family that has only been identified in a few bat species. Bats have been associated with several emerging zoonotic diseases such as Ebola and SARS.

<i>Sepik virus</i> Mosquito transmitted virus endemic to Papua New Guinea

Sepik virus (SEPV) is an arthropod-borne virus (arbovirus) of the genus Flavivirus and family Flaviviridae. Flaviviridae is one of the most well characterized viral families, as it contains many well-known viruses that cause diseases that have become very prevalent in the world, like Chikungunya virus and Dengue virus. The genus Flavivirus is one of the largest viral genera and encompasses over 50 viral species, including tick and mosquito borne viruses like Yellow fever virus and West Nile virus. Sepik virus is much less well known and has not been as well-classified as other viruses because it has not been known of for very long. Sepik virus was first isolated in 1966 from the mosquito Mansoniaseptempunctata, and it derives its name from the Sepik River area in Papua New Guinea, where it was first found. The geographic range of Sepik virus is limited to Papua New Guinea, due to its isolation.

References

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  2. Lundström JO (1999). "Mosquito-borne viruses in western Europe: a review". Journal of Vector Ecology. 24 (1): 1–39. PMID   10436876.
  3. Lu Z, Lu XJ, Fu SH, Zhang S, Li ZX, Yao XH, Feng YP, Lambert AJ, Ni da X, Wang FT, Tong SX, Nasci RS, Feng Y, Dong Q, Zhai YG, Gao XY, Wang HY, Tang Q, Liang GD (2009). "Tahyna virus and human infection, China". Emerging Infectious Diseases. 15 (2): 306–9. doi:10.3201/eid1502.080722. PMC   2657618 . PMID   19193280.
  4. 1 2 Gratz, Norman (2006-11-02). Vector- and Rodent-Borne Diseases in Europe and North America: Distribution, Public Health Burden, and Control. Cambridge University Press. ISBN   9780521854474.
  5. 1 2 Kallio-Kokko, Hannimari; Uzcategui, Nathalie; Vapalahti, Olli; Vaheri, Antti (2005). "Viral zoonoses in Europe". FEMS Microbiology Reviews. 29 (5): 1051–1077. doi: 10.1016/j.femsre.2005.04.012 . ISSN   1574-6976. PMID   16024128.

Further reading