''Sindbis virus'' (SINV) is a member of the ''
Togaviridae This category is for articles about virus families (or redirects to such articles). There should be no subcategories.
families
Families (biology) ...
'' family, in the ''
Alphavirus
''Alphavirus'' is a genus of RNA viruses, the sole genus in the ''Togaviridae'' family. Alphaviruses belong to group IV of the Baltimore classification of viruses, with a positive-sense, single-stranded RNA genome. There are 32 alphaviruses ...
'' genus. The virus was first isolated in 1952 in
Cairo
Cairo ( ; ar, القاهرة, al-Qāhirah, ) is the Capital city, capital of Egypt and its largest city, home to 10 million people. It is also part of the List of urban agglomerations in Africa, largest urban agglomeration in Africa, List of ...
,
Egypt
Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Medit ...
. The virus is transmitted by
mosquitoes
Mosquitoes (or mosquitos) are members of a group of almost 3,600 species of small Diptera, flies within the family Culicidae (from the Latin ''culex'' meaning "gnat"). The word "mosquito" (formed by ''mosca'' and diminutive ''-ito'') is Spanish ...
(''
Culex
''Culex'' is a genus of mosquitoes, several species of which serve as vectors of one or more important diseases of birds, humans, and other animals. The diseases they vector include arbovirus infections such as West Nile virus, Japanese encep ...
'' and
Culiseta). SINV is linked to
Pogosta
''Pogost'' (russian: погост, from Old East Slavic: погостъ) is a historical term with several meanings in the Russian language. It has also been borrowed into Latgalian (''pogosts''), Finnish (''pogosta'') and Latvian (''pagasts' ...
disease
[Kurkela S, Manni T, Vaheri A, Vapalahti O]
Causative agent of Pogosta disease isolated from blood and skin lesions
Emerg Infect Dis erial on the Internet Published 2004 May. (accessed 2007-10-16) (
Finland
Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of B ...
),
Ockelbo
Ockelbo is a locality and the seat of Ockelbo Municipality, Gävleborg County, Sweden with 2,724 inhabitants in 2010.
The name Ockelbo, spelled ''De oklabo'' in 1314, contains an old marine name ''*Ukle'', referring to modern-day Lake Bysjön. ...
disease (
Sweden) and
Karelian fever (
Russia
Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...
). In humans, the symptoms include
arthralgia
Arthralgia (from Greek ''arthro-'', joint + ''-algos'', pain) literally means ''joint pain''. Specifically, arthralgia is a symptom of injury, infection, illness (in particular arthritis), or an allergic reaction to medication.
According to MeSH, ...
,
rash
A rash is a change of the human skin which affects its color, appearance, or texture.
A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, c ...
and
malaise. Sindbis virus is widely and continuously found in insects and vertebrates in Eurasia, Africa, and Oceania. Clinical infection and disease in humans however has almost only been reported from Northern Europe (Finland, Sweden, Russian Karelia), where SINV is endemic and where large outbreaks occur intermittently. Cases are occasionally reported in Australia, China, and South Africa.
SINV is an
arbovirus
Arbovirus is an informal name for any virus that is transmitted by arthropod vectors. The term ''arbovirus'' is a portmanteau word (''ar''thropod-''bo''rne ''virus''). ''Tibovirus'' (''ti''ck-''bo''rne ''virus'') is sometimes used to more sp ...
, it is
arthropod-
borne, and it is maintained in nature by transmission between
vertebrate
Vertebrates () comprise all animal taxa within the subphylum Vertebrata () (chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, with c ...
(bird) hosts and
invertebrate
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...
(mosquito) vectors. Humans are infected with Sindbis virus when bitten by an infected mosquito.
Virus physiology
Structure, genome & replication
Sindbis viruses are enveloped particles with an icosahedral
capsid
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 ...
, with a positive single stranded
RNA genome, with an approximate size of 11.7 kb. The RNA has a
5'-cap and 3'-polyadenylated tail, and therefore serves directly as messenger RNA (
mRNA
In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of synthesizing a protein.
mRNA is created during the ...
) in a host cell. The genome encodes four non-structural proteins, the capsid, and two envelope proteins. This is characteristic of all
Togaviruses.
Replication is
cytoplasmic and rapid. The genomic RNA is partially
translated
Translation is the communication of the meaning of a source-language text by means of an equivalent target-language text. The English language draws a terminological distinction (which does not exist in every language) between ''transla ...
at the 5’ end to produce the non-structural proteins which are then involved in genome replication and the production of new genomic RNA and a shorter sub-genomic RNA strand. This sub-genomic strand is
translated
Translation is the communication of the meaning of a source-language text by means of an equivalent target-language text. The English language draws a terminological distinction (which does not exist in every language) between ''transla ...
into the structural proteins. The viruses assemble at the host cell surfaces and acquire their
envelope
An envelope is a common packaging item, usually made of thin, flat material. It is designed to contain a flat object, such as a letter or card.
Traditional envelopes are made from sheets of paper cut to one of three shapes: a rhombus, a sh ...
through
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 ...
.
A
non-coding RNA element has been found to be essential for Sindbis virus genome replication.
has been demonstrated between
RNAs of Sindbis virus.
The mechanism of recombination appears to be template switching (copy choice) during RNA replication.
[
]
See also
* Alphavirus infection
References
MicrobiologyBytes: Togaviruses
ICTVdB—The Universal Virus Database, version 4.
External links
Virus Pathogen Database and Analysis Resource (ViPR): Togaviridae
{{Taxonbar, from=Q2302993
Alphaviruses