The

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

''Sudan ebolavirus'' is a virological taxon included in the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

Ebolavirus The genus ''Ebolavirus'' (- or ; - or ) is a virological taxon included in the family '' Filoviridae'' (filament-shaped viruses), order ''Mononegavirales''. The members of this genus are called ebolaviruses, and encode their genome in the for ...

'',

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Filoviridae ''Filoviridae'' () is a family of single-stranded negative-sense RNA viruses in the order ''Mononegavirales''. Two members of the family that are commonly known are Ebola virus and Marburg virus. Both viruses, and some of their lesser known re ...

'', order ''

Mononegavirales ''Mononegavirales'' is an order of negative-strand RNA viruses which have nonsegmented genomes. Some common members of the order are Ebola virus, human respiratory syncytial virus, measles virus, mumps virus, Nipah virus, and rabies virus. A ...

''. The species has a single

virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsk ...

member, Sudan virus (SUDV). The members of the species are called Sudan ebolaviruses. It was discovered in 1977 and causes Ebola clinically indistinguishable from the

ebola Zaire ''Zaire ebolavirus'', more commonly known as Ebola virus (; EBOV), is one of six known species within the genus ''Ebolavirus''. Four of the six known ebolaviruses, including EBOV, cause a severe and often fatal hemorrhagic fever in humans and o ...

strain, but is less transmissible than it. Unlike with ebola Zaire there is no vaccine available.

Nomenclature

The name ''Sudan ebolavirus'' is derived from '' Sudan'' (the country in which Sudan virus was first discovered) and the taxonomic suffix ''ebolavirus'' (which denotes an ebolavirus species). The species was introduced in 1998 as ''Sudan Ebola virus''. In 2002, the name was changed to ''Sudan ebolavirus''. A virus of the genus ''

'' is a member of the species ''Sudan ebolavirus'' if: * it is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

in Sudan and/or

Uganda }), is a landlocked country in East Africa. The country is bordered to the east by Kenya, to the north by South Sudan, to the west by the Democratic Republic of the Congo, to the south-west by Rwanda, and to the south by Tanzania. The sou ...

* it has a

genome In the fields of molecular biology and genetics, 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 g ...

with three gene overlaps (''VP35''/''VP40'', ''GP''/''VP30'', ''VP24''/''L'') * it has a genomic sequence different from

Ebola virus ''Zaire ebolavirus'', more commonly known as Ebola virus (; EBOV), is one of six known species within the genus '' Ebolavirus''. Four of the six known ebolaviruses, including EBOV, cause a severe and often fatal hemorrhagic fever in humans and o ...

by ≥30% but different from that of Sudan virus by <30% ''Sudan virus'' (SUDV) is one of six known viruses within the

'' and one of the four that causes Ebola virus disease (EVD) in

human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, cultu ...

s and other

primate Primates are a diverse order of mammals. They are divided into the strepsirrhines, which include the lemurs, galagos, and lorisids, and the haplorhines, which include the tarsiers and the simians ( monkeys and apes, the latter including ...

s; it is the sole member of the species ''Sudan ebolavirus''. SUDV is a

Select agent Under United States law, Biological select agents or toxins (BSATs) — or simply select agents for short — are bio-agents which (since 1997) have been declared by the U.S. Department of Health and Human Services (HHS) or by the U.S. Departme ...

World Health Organization The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level of ...

Risk Group 4 Pathogen (requiring Biosafety Level 4-equivalent containment),

National Institutes of Health The National Institutes of Health, commonly referred to as NIH (with each letter pronounced individually), is the primary agency of the United States government responsible for biomedical and public health research. It was founded in the late ...

National Institute of Allergy and Infectious Diseases The National Institute of Allergy and Infectious Diseases (NIAID, ) is one of the 27 institutes and centers that make up the National Institutes of Health (NIH), an agency of the United States Department of Health and Human Services (HHS). NIAID's ...

Category A Priority Pathogen, Centers for Disease Control and Prevention Bioterrorism, Category A Bioterrorism Agent, and listed as a Biological Agent for Export Control by the Australia Group. The first known outbreak of EVD occurred due to Sudan virus in South Sudan between June and November 1976, infecting 284 people and killing 151, with the first identifiable case on 27 June 1976.

Use of term

Sudan virus (abbreviated SUDV) was first described in 1977. It is the single member of the

''Sudan ebolavirus'', which is included into the International Committee on Taxonomy of Viruses, genus ''

'', International Committee on Taxonomy of Viruses, family ''

'', International Committee on Taxonomy of Viruses, order ''

''. The name Sudan virus is derived from ''South Sudan'' (where it was first discovered before South Sudan seceded from Sudan) and the taxonomic suffix ''virus''.

Previous designations

Sudan virus was first introduced as a new "strain" of Ebola virus in 1977. Sudan virus was described as "Ebola haemorrhagic fever" in a 1978 WHO report describing the 1976 Sudan outbreak. In 2000, it received the designation Sudan Ebola virus and in 2002 the name was changed to Sudan ebolavirus. Previous abbreviations for the virus were EBOV-S (for Ebola virus Sudan) and most recently SEBOV (for Sudan Ebola virus or Sudan ebolavirus). The virus received its final designation in 2010, when it was renamed Sudan virus (SUDV).

Virus inclusion criteria

A virus of the species ''Sudan ebolavirus'' is a Sudan virus (SUDV) if it has the properties of Sudan ebolaviruses and if its

diverges from that of the prototype Sudan virus, Sudan virus variant Boniface (SUDV/Bon), by ≤10% at the nucleotide level.

Disease

SUDV is one of four ebolaviruses that causes Ebola virus disease (EVD) in humans (in the literature also often referred to as Ebola hemorrhagic fever, EHF). EVD due to SUDV infection cannot be differentiated from EVD caused by other ebolaviruses by clinical observation alone, which is why the clinical presentation and pathology of infections by all ebolaviruses is presented together on a separate page. The strain is less transmissible than Zaire ebolavirus. In the past, SUDV has caused the following EVD outbreaks:

Vaccine development

As of 2022, there are six experimental vaccines but only three have advanced to the stage where human clinical trials have begun. As the Public Health Agency of Canada developed a candidate RVSV vaccines, RVSV vaccine for Sudan ebolavirus. Merck Group, Merck was developing it, but had discontinued development; Merck's monopolies on rVSV techniques, acquired with funding from GAVI, are not available to others developing rVSV vaccines. As of 2021 GeoVax was developing MVA-SUDV-VLP, which is a modified vaccinia Ankara virus producing Sudan virus-like particles; early data from their research showed the GeoVax vaccine candidate to be 100% effective at preventing death from the Sudan ebolavirus in animals. An adenovirus based vaccine previously licensed by GSK plc, GSK was donated to and further developed by the Sabin Vaccine Institute in partnership with the Vaccine Research Center at the US National Institute of Allergy and Infectious Diseases; as of October 2022, it will be offered to contacts of known SDV cases in the 2022 Uganda Ebola outbreak as part of a clinical trial.

Ecology

The ecology of SUDV is currently unclear and no reservoir host has yet been identified. Therefore, it remains unclear how SUDV was repeatedly introduced into human populations. As of 2009, bats have been suspected to harbor the virus because infectious Marburg virus (MARV), a distantly related filovirus, has been isolated from bats, and because traces (but no infectious particles) of the more closely related

(EBOV) were found in bats as well.

Molecular biology

SUDV is basically uncharacterized on a molecular level. However, its genomic sequence, and with it the Genome, genomic organization and the conservation of individual open reading frames, is similar to that of the other four known ebolaviruses. It is therefore currently assumed that the knowledge obtained for EBOV can be Extrapolation, extrapolated to SUDV and that all SUDV proteins behave analogous to those of EBOV.

References

External links

ICTV Files and Discussions - Discussion forum and file distribution for the International Committee on Taxonomy of Viruses
{{Taxonbar, from=Q7633348 Animal viral diseases Arthropod-borne viral fevers and viral haemorrhagic fevers Biological weapons Hemorrhagic fevers Ebolaviruses Tropical diseases Virus-related cutaneous conditions Zoonoses Primate diseases Infraspecific virus taxa