''Orthonairovirus'' is a genus of viruses in the family ''

Nairoviridae ''Nairoviridae'' is a family of viruses in the order '' Hareavirales''. Its name derives from Nairobi sheep disease, caused by the member ''Nairobi sheep disease orthonairovirus Nairobi sheep disease virus (NSDV), also known as Ganjam virus, i ...

'' of the order ''

Hareavirales ''Hareavirales'' is an order of viruses. The order belongs to the class '' Bunyaviricetes'' and contains nine families. Taxonomy The order contains the following families: * '' Arenaviridae'' * '' Discoviridae'' * '' Konkoviridae'' * '' Leishbu ...

'' which includes viruses with circular, negative-sense single stranded RNA. The name is derived from the Nairobi sheep disease which affects the gastrointestinal tracts of sheep and goats. All viruses in this genus are tick-borne viruses with human or other vertebrate hosts.

Structure

The

virions A virion (plural, ''viria'' or ''virions'') is an inert virus particle capable of invading a cell. Upon entering the cell, the virion disassembles and the genetic material from the virus takes control of the cell infrastructure, thus enabling th ...

for viruses in this genus have a spherical shape. They range in size from about 80–120 nm in diameter, with 50% of their weight attributed to proteins and 20–30% of their weight attributed to lipids. The ribonucleocapsid is filamentous, having a length of about 200-300 nm and a width of about 2–2.5 nm. These nucleocapsids are surrounded by a single envelope that has projections made of glycoproteins protruding from its surface. These projections evenly cover the surface of the virion, and are about 5–10 nm long. They aid in attachment to the host receptor in replication.

Genome

Nairovirus genomes are negative sense, single-stranded RNA. The complete

genome A genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as ...

is about 17,100–22,800

nucleotide Nucleotides are Organic compound, organic molecules composed of a nitrogenous base, a pentose sugar and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both o ...

s long, and is divided into three segments: large, medium, and small. The large segment is about 11000–14400 nucleotides long (11–14.4 kb), and it encodes the viral polymerase. The medium segment is about 4,400–6,300 nucleotides long (4.4–6.3 kb), and it encodes for

glycoprotein Glycoproteins are proteins which contain oligosaccharide (sugar) chains covalently attached to amino acid side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known a ...

s G¬n and Gc. The small segment is about 1,700–2,100 nucleotides long (1.7–2.1 kb), and it encodes the

nucleocapsid A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or ma ...

protein.< The genome has terminally redundant sequences, with the sequences being repeated at both ends. The terminal nucleotides are base-paired forming, non-covalently closed,

circular RNA In molecular biology, circular ribonucleic acid (or circRNA) is a type of single-stranded RNA which, unlike linear RNA, forms a covalently closed continuous loop. In circular RNA, the 3' and 5' ends normally present in an RNA molecule have been ...

. Both the 5’ and 3’ ends have conserved regions, 9 nucleotides in length. The sequences are, 5’end: UCUCAAAGA, and 3’end: AGAGUUUCU.

Replication

Nairoviruses attach to the host receptor by their Gn-Gc glycoprotein dimer. The virus is then endocytosed into the host cell via a

vesicle Vesicle may refer to: ; In cellular biology or chemistry * Vesicle (biology and chemistry), a supramolecular assembly of lipid molecules, like a cell membrane * Synaptic vesicle ; In human embryology * Vesicle (embryology), bulge-like features ...

. The ribonucleocapsid segments are released into the

cytoplasm The cytoplasm describes all the material within a eukaryotic or prokaryotic cell, enclosed by the cell membrane, including the organelles and excluding the nucleus in eukaryotic cells. The material inside the nucleus of a eukaryotic cell a ...

, commencing

transcription Transcription refers to the process of converting sounds (voice, music etc.) into letters or musical notes, or producing a copy of something in another medium, including: Genetics * Transcription (biology), the copying of DNA into RNA, often th ...

. Transcription and replication occur within the cell, and the newly synthesized virions are released by

budding Budding or blastogenesis is a type of asexual reproduction in which a new organism develops from an outgrowth or bud due to cell division at one particular site. For example, the small bulb-like projection coming out from the yeast cell is kno ...

Transmission and distribution

Members of this viral genus infect many different

vertebrate Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebra ...

hosts A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places * Host, Pennsylvania, a village in Berks County * Host Island, in the Wilhelm Archipelago, Antarctica People * ...

, and are transmitted via ticks. Members of the genus ''Nairovirus'' may be found the world over, wherever their

arthropod Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...

vectors and vertebrate hosts are found together.

Taxonomy

The genus contains the following species, listed by scientific name and followed by the exemplar virus of the species: * ''Orthonairovirus abuhammadense'', Abū Ḥammād virus * ''Orthonairovirus abuminaense'', Abū Mīnā virus * ''Orthonairovirus amblyommae'',

Kupe virus Kupe virus is a species of virus in the genus ''Orthonairovirus''. History The virus was isolated from pooled ticks ('' Amblyomma gemma'' and ''Rhipicephalus pulchellus'') collected from cattle hides in Nairobi, Kenya, in October 1999.Sang R, On ...

* ''Orthonairovirus antuense'', Antú virus * ''Orthonairovirus artashatense'',

Artashat virus Artashat virus (ARTSV), is a species in the genus ''Orthonairovirus''. It was first isolated in Armenia in 1972 from ''Ornithodoros alactagalis'', a soft tick of the family Argasidae. References

Nairoviridae {{virus-stub ...

* ''Orthonairovirus australiaense'',

Vinegar Hill virus Vinegar () is an aqueous solution of diluted acetic acid and trace compounds that may include flavorings. Vinegar typically contains from 5% to 18% acetic acid by volume. Usually, the acetic acid is produced by a double fermentation, converting ...

* ''Orthonairovirus avalonense'',

Avalon virus Avalon () is an island featured in the Arthurian legend. It first appeared in Geoffrey of Monmouth's 1136 ''Historia Regum Britanniae'' as a place of magic where King Arthur's sword Excalibur was made and later where Arthur was taken to recover ...

* ''Orthonairovirus bandiaense'',

Bandia virus Bandia is a census town in Udham Singh Nagar district in the state of Uttarakhand, India. Geography Bandia is located at . Demographics India census A census (from Latin ''censere'', 'to assess') is the procedure of systematically acquirin ...

* ''Orthonairovirus buranaense'',

Burana virus Burana may refer to: * Burana, Kyrgyzstan, a village in Kyrgyzstan ** Burana Tower, a tower near the village in Kyrgyzstan * Burana (drug), a nonsteroidal anti-inflammatory drug (NSAID) by Orion Corporation Orion may refer to: Common meani ...

* ''Orthonairovirus bushkeyense'', Farallon virus * ''Orthonairovirus chimense'',

Chim virus Chim may refer to: *Chim, Iran. a village in Jarahi Rural District, Iran *CHIM-FM, a radio station in Timmins, Ontario, Canada **CHIM-FM-5, a former radio station in Red Deer, Alberta, Canada, rebroadcaster of CHIM-FM People

*Zhan (surname), r ...

* ''Orthonairovirus clomorense'', Clo Mor virus * ''Orthonairovirus crocidurae'', Wufeng Crocidura attenuata orthonairovirus 1 * ''Orthonairovirus dermacentoris'', Pacific Coast tick nairovirus * ''Orthonairovirus dugbeense'', Dugbe virus * ''Orthonairovirus erveense'', Erve virus * ''Orthonairovirus esteroense'',

Estero Real virus Estero (Spanish for "estuary") is an incorporated village in Lee County, Florida, United States, located directly beside the first aquatic nature preserve established in Florida: The Estero Bay Aquatic Preserve, otherwise referred to as Estero B ...

* ''Orthonairovirus gossasense'',

Gossas virus Gossas is a town and urban commune in Fatick Region in western Senegal, about 90 km from the capital Dakar. Transport The town is served by a station on the Dakar-Niger Railway. See also * Transport in Senegal * Railway stations in ...

* ''Orthonairovirus gubboense'', Gubbo nairovirus * ''Orthonairovirus haemorrhagiae'', Crimean-Congo hemorrhagic fever virus * ''Orthonairovirus hazaraense'',

Hazara virus In 1954 the Hazara virus, one of the 34 tick-borne viruses of the genus '' Orthonairovirus'', was discovered in Pakistan in the ''Ixodes'' tick native to that region. Today this virus is studied in mice in an attempt to develop treatments for the ...

* ''Orthonairovirus huangpiense'', Huángpí tick virus 1 * ''Orthonairovirus issykkulense'',

Issyk-kul virus Issyk-Kul () or Ysyk-Köl (, ; ) is an endorheic saline lake in the western Tianshan Mountains in eastern Kyrgyzstan, just south of a dividing range separating Kyrgyzstan from Kazakhstan. It is the List of lakes by depth, eighth-deepest lake in t ...

* ''Orthonairovirus japonicum'',

Tofla virus Tofla virus (''Orthonairovirus japonicum'') is a species of virus in the genus ''Orthonairovirus'' belonging to the Crimean-Congo hemorrhagic fever serogroup. It was isolated in 2016 from ''Ixodid'' in Japan. See also * Wetland virus Wet ...

* ''Orthonairovirus kasokeroense'', Kasokero virus * ''Orthonairovirus keterehense'', Keterah virus * ''Orthonairovirus khani'', Dera Ghazi Khan virus * ''Orthonairovirus lambarenense'', Lamusara virus * ''Orthonairovirus lusakaense'', Leopards Hill virus * ''Orthonairovirus macquariense'', Taggert virus * ''Orthonairovirus manidae'',

Pangolin orthonairovirus Pangolins, sometimes known as scaly anteaters, are mammals of the order Pholidota (). The one extant family, the Manidae, has three genera: ''Manis'', ''Phataginus'', and ''Smutsia''. ''Manis'' comprises four species found in Asia, while ''Pha ...

* ''Orthonairovirus meihuashanense'', Méihua Mountain virus * ''Orthonairovirus meramense'',

Meram virus Meram is a municipality and district of Konya Province, Turkey. Its area is 1,822 km2, and its population is 348,325 (2022). Meram is one of the central districts of Konya, along with the districts of Karatay and Selçuklu. It covers the sout ...

* ''Orthonairovirus nairobiense'', Nairobi sheep disease virus * ''Orthonairovirus parahaemorrhagiae'',

Aigai virus Aigai () or Latin(ized) Aegae/ Ægæ may refer to the following places and jurisdictions : * Aigai (Aeolis), ancient city and former bishopric of the Aeolian dodecapolis in Asia Prima, now Nemrutkale or Nemrut Kalesi near the modern city Aliağa i ...

* ''Orthonairovirus peruense'',

Punta Salinas virus Punta is an Afro-Indigenous dance and cultural music deeply rooted in the cultural traditions of the Garifuna of Honduras. It heavily incorporates West African/Central African drumming, the dance primarily of Angola and Congo origins. The musi ...

* ''Orthonairovirus qalyubense'',

Qalyub virus Qalyub virus (''Orthonairovirus qalyubense'') is a virus discovered in a rat's nest in a tomb wall in the Egyptian town of Qalyub ( ) in 1952. The primary vector for transmission is the ''Carios erraticus'' tick, and thus it is an arbovirus. T ...

* ''Orthonairovirus randallense'',

Sapphire II virus Sapphire is a precious gemstone, a variety of the mineral corundum, consisting of aluminium oxide () with trace amounts of elements such as iron, titanium, cobalt, lead, chromium, vanadium, magnesium, boron, and silicon. The name ''sapphire ...

* ''Orthonairovirus sakhalinense'', Sakhalin virus * ''Orthonairovirus sinense'', Orthonairovirus sp. strain YS * ''Orthonairovirus soldadoense'',

Soldado virus Soldado is a Spanish and Portuguese word meaning soldier. It may refer to: Arts and media *''El Soldado'', a 1634 play by Luis Quiñones de Benavente *''El Soldado'', an 1892 play by Adolfo León Gómez *"El Soldado", a song recorded by Barbarito ...

* ''Orthonairovirus songlingense'', Sōnglǐng virus * ''Orthonairovirus sulinaense'',

Sulina virus Sulina () is a town and free port in Tulcea County, Northern Dobruja, Romania, at the mouth of the Sulina branch of the Danube. It is the easternmost point of Romania. History During the mid-Byzantine period, Sulina was a small cove, and in the ...

* ''Orthonairovirus sunci'', Cencurut virus * ''Orthonairovirus tachengense'', Tǎchéng tick virus 1 * ''Orthonairovirus thiaforaense'', Thiafora virus * ''Orthonairovirus tomdiense'', Tamdy virus * ''Orthonairovirus tunisense'',

Tunis virus Tunis (, ') is the capital and largest city of Tunisia. The greater metropolitan area of Tunis, often referred to as "Grand Tunis", has about 2,700,000 inhabitants. , it is the third-largest city in the Maghreb region (after Casablanca and Algie ...

* ''Orthonairovirus wenzhouense'', Wēnzhōu tick virus * ''Orthonairovirus yezoense'',

Yezo virus Yezo virus (''Orthonairovirus yezoense'') is a species of virus in the genus ''Orthonairovirus'', discovered 2021 in Japan, circulating in mammals and ticks, causing a mild febrile illness in humans. Virology Yezo virus is classified into the ge ...

* ''Orthonairovirus yogueense'',

Yogue virus Yogue virus (''Orthonairovirus yogueense'') is a species of virus in the genus ''Orthonairovirus''. Its only known host is ''Rousettus aegyptiacus The Egyptian fruit bat or Egyptian rousette (''Rousettus aegyptiacus'') is a species of megabat ...

* ''Orthonairovirus zirkuense'', Zirqa virus

Clinical importance

Members of this viral genus which infect humans include Crimean–Congo hemorrhagic fever, Dugbe virus, Nairobi sheep disease virus, Songling virus,

Tacheng tick virus TachengThe official spelling according to (), also known as Tarbagatay, Chuguchak or Qoqek, is a county-level city and the administrative seat of Tacheng Prefecture, in northern Ili Kazakh Autonomous Prefecture, Xinjiang. The Chinese name "Tache ...

Beiji orthonairovirus The baiji (''Lipotes vexillifer'') is a probably extinct species of freshwater dolphin native to the Yangtze river system in China. It is thought to be the first dolphin species driven to extinction due to the impact of humans. This dolphin is ...

and

Wetland virus Wetland virus or WELV is a tick borne '' Orthonairovirus'' which can infect humans. It can produce fever, headache, dizziness, malaise, arthritis and less commonly petechiae, localized lymphadenopathy. Complications may include neurological symp ...

. Except for the first they cause relatively mild disease. Kasokero virus and Erve virus are likely also pathogenic for humans.

Evolution

Phylogenetic analysis has shown that these viruses fall into two major monophyletic groups, the hard (''

Ixodidae The Ixodidae are the family of hard ticks or scale ticks, one of the three families of ticks, consisting of 771 species, . They are known as 'hard ticks' because they have a scutum or hard shield, which the other major family of ticks, the 'sof ...

'') and soft (''

Argasidae The Argasidae are the family of soft ticks, one of the three families of ticks. The family contains 193 species, although the composition of the genera is less certain, and more study is needed before the genera can become stable. The currently a ...

'') tick-vectored groups. Fossil and phylogenetic data places the hard tick-soft tick divergence between and . This suggests that the Nairoviruses have been associated with these ticks for over 100 million years. Additionally, nairoviruses vectored by ticks of the genera ''

Argas ''Argas'' is a genus of tick Ticks are parasitic arachnids of the order Ixodida. They are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, and species, but can bec ...

'', ''Carios'' and ''

Ornithodoros ''Ornithodoros'' is a genus in the soft-bodied tick family, Argasidae. It is distinguished from other genera in the family by the absence of a lateral 'suture' line. It is the largest genus within Argasidae, consisting of approximately 130 specie ...

'' form three separate monophyletic lineages, again supporting the suggestion of host-virus cospeciation. The hard bodied tick serogroups are * Crimean-Congo hemorrhagic fever * Nairobi sheep disease * Sakhalin * Tamdy The soft bodied tick serogroups are * Hughes * Dera Ghazi Khan * Qalyub The tick vectors for the Kasokero and Thiafora serogroups are not currently known.

References

External links

ICTV Report: ''Nairoviridae''

{{Taxonbar, from=Q29001085 Nairoviridae Virus genera