The

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

''Taï Forest ebolavirus'' () is a virological taxon included in the genus ''

Ebolavirus The genus ''Ebolavirus'' (- or ; - or ) is a International Committee on Taxonomy of Viruses, virological taxon included in the family ''Filoviridae'' (filament-shaped viruses), order ''Mononegavirales''. The members of this genus are called ebo ...

'', family ''

Filoviridae ''Filoviridae'' () is a International Committee on Taxonomy of Viruses, family of RNA virus#Group_V_–_negative-sense_ssRNA_viruses, single-stranded negative-sense RNA viruses in the order (biology), order ''Mononegavirales''. Two members of the ...

'', order ''

Mononegavirales ''Mononegavirales'' is an order of negative-strand RNA viruses which have nonsegmented genomes. Some members that cause human disease in this order include Ebola virus, human respiratory syncytial virus, measles virus, mumps virus, Nipah viru ...

''. The species has a single

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

member, Taï Forest virus (TAFV). The members of the species are called Taï Forest ebolaviruses. ''Tai Forest ebolavirus'' has been seen in a single human infection due to contact with chimpanzees from the Tai Forest in

Côte d'Ivoire Ivory Coast, also known as Côte d'Ivoire and officially the Republic of Côte d'Ivoire, is a country on the southern coast of West Africa. Its capital city of Yamoussoukro is located in the centre of the country, while its largest city and ...

Nomenclature

The name ''Taï Forest ebolavirus'' is derived from '' Parc National de Taï'' (the name of a national park in

, where Taï Forest virus was first discovered) and the taxonomic

suffix In linguistics, a suffix is an affix which is placed after the stem of a word. Common examples are case endings, which indicate the grammatical case of nouns and adjectives, and verb endings, which form the conjugation of verbs. Suffixes can ca ...

''ebolavirus'' (which denotes an ebolavirus species). According to the rules for taxon naming established by the

International Committee on Taxonomy of Viruses The International Committee on Taxonomy of Viruses (ICTV) authorizes and organizes the taxonomic classification of and the nomenclature for viruses. The ICTV develops a universal taxonomic scheme for viruses, and thus has the means to appropri ...

(ICTV), the name ''Taï Forest ebolavirus'' is always to be capitalized, italicized, never abbreviated, and to be preceded by the word "species". The names of its members (Taï Forest ebolaviruses) are to be capitalized, are not italicized, and used without articles. The species was introduced in 1998 as ''Cote d'Ivoire Ebola virus''. In 2002, the name was changed to ''Cote d'Ivoire ebolavirus''. The name was proposed to be changed to ''Taï Forest ebolavirus'' in 2010, and this proposal was immediately accepted by the ICTV. A virus of the genus ''

'' is a member of the species ''Taï Forest ebolavirus'' if: * it is endemic in Côte d'Ivoire * it has a genome with three gene overlaps (''VP35''/''VP40'', ''GP''/''VP30'', ''VP24''/''L'') * it has a genomic sequence different from

Ebola virus ''Orthoebolavirus zairense'' or 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 vira ...

by ≥30% but different from that of Taï Forest virus by <30%. Taï Forest virus (; TAFV) is a close relative of the much more commonly known

(EBOV). TAFV causes severe

disease A disease is a particular abnormal condition that adversely affects the structure or function (biology), function of all or part of an organism and is not immediately due to any external injury. Diseases are often known to be medical condi ...

primates Primates is an order of mammals, which is further divided into the strepsirrhines, which include lemurs, galagos, and lorisids; and the haplorhines, which include tarsiers and simians ( monkeys and apes). Primates arose 74–63 ...

, the

Ebola Ebola, also known as Ebola virus disease (EVD) and Ebola hemorrhagic fever (EHF), is a viral hemorrhagic fever in humans and other primates, caused by ebolaviruses. Symptoms typically start anywhere between two days and three weeks after in ...

hemorrhagic fever. TAFV is a Select Agent,

World Health Organization The World Health Organization (WHO) is a list of specialized agencies of the United Nations, specialized agency of the United Nations which coordinates responses to international public health issues and emergencies. It is headquartered in Gen ...

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

National Institutes of Health The National Institutes of Health (NIH) is the primary agency of the United States government responsible for biomedical and public health research. It was founded in 1887 and is part of the United States Department of Health and Human Service ...

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. NIAID's mis ...

Category A Priority Pathogen,

Centers for Disease Control and Prevention The Centers for Disease Control and Prevention (CDC) is the National public health institutes, national public health agency of the United States. It is a Federal agencies of the United States, United States federal agency under the United S ...

Category A Bioterrorism Agent, and listed as a Biological Agent for Export Control by the Australia Group.

Use of term

Taï Forest virus (abbreviated TAFV) was first described in 1995 as a new "strain" of

. It is the single member of the

''Taï Forest ebolavirus'', which is included into the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

'',

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

'', order ''

''. The name Taï Forest virus is derived from '' Parc National de Taï'' (the name of a national park in

, where it was first discovered) and the taxonomic

''virus''. According to the rules for taxon naming established by the

(ICTV), the name Taï Forest virus is always to be capitalized, but (in contrast to taxon names, e. g. genus and species names) is never italicized, and may be

abbreviated An abbreviation () is a shortened form of a word or phrase, by any method including shortening, contraction, initialism (which includes acronym), or crasis. An abbreviation may be a shortened form of a word, usually ended with a trailing per ...

(with TAFV being the official abbreviation).

Previous designations

Taï Forest virus was first introduced as a new "strain" of Ebola virus in 1995. In 2000, it received the designation Côte d'Ivoire Ebola virus, and in 2002 the name was changed to Côte d'Ivoire ebolavirus. (both times misspelling "Côte"). Other names circulating in the literature were the correct Côte d'Ivoire Ebola virus and Côte d'Ivoire ebolavirus, and the jargon terms Ivory Coast Ebola virus and Ivory Coast ebolavirus. Previous abbreviations for the virus were EBOV-CI (for Ebola virus Côte d'Ivoire or Ebola virus Côte d'Ivoire), EBOV-IC (for Ebola virus Ivory Coast), ICEBOV (for Ivory Coast Ebola virus or Ivory Coast ebolavirus) and most recently CIEBOV (for Cote d;Ivoire Ebola virus, Côte d'Ivoire Ebola virus, Côte d'Ivoire ebolavirus or Côte d'Ivoire ebolavirus). The virus received its final designation in 2010, when it was renamed Taï Forest virus (TAFV).

Virus inclusion criteria

A virus of the species ''Taï Forest ebolavirus'' is a Taï Forest virus (TAFV) if it has the properties of Taï Forest ebolaviruses and if its

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 ...

diverges from that of the prototype Taï Forest virus, Taï Forest virus variant Côte d'Ivoire (TAFV/CI), by ≤10% at the

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 ...

level.

Disease

TAFV is one of four ebolaviruses that causes

Ebola virus disease Ebola, also known as Ebola virus disease (EVD) and Ebola hemorrhagic fever (EHF), is a viral hemorrhagic fever in humans and other primates, caused by ebolaviruses. Symptoms typically start anywhere between two days and three weeks after infe ...

(EVD) in humans (in the literature also often referred to as Ebola hemorrhagic fever, EHF). EVD due to TAFV 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 (see

). TAFV made its first and thus far only known appearance in 1994 during a viral hemorrhagic fever

epizootic In epizoology, an epizootic (or epizoötic, from Greek: ''epi-'' "upon" + ''zoon'' "animal") is a disease event in a nonhuman animal population analogous to an epidemic in humans. An epizootic disease (or ) may occur in a specific locale (an ...

among western chimpanzees (Pan troglodytes verus) in

Taï National Park Taï National Park () is a national park in Ivory Coast that contains one of the last areas of primary rainforest in West Africa. It was inscribed as a World Heritage Site in 1982 due to the diversity of its flora and fauna. Five mammal species ...

. As more dead western chimpanzees were discovered, many tested positive for infection with an ebolavirus distinct from those already known. One of the scientists performing the necropsies on the infected western chimpanzees contracted TAFV. She developed symptoms similar to those of

dengue fever Dengue fever is a mosquito-borne disease caused by dengue virus, prevalent in tropical and subtropical areas. Asymptomatic infections are uncommon, mild cases happen frequently; if symptoms appear, they typically begin 3 to 14 days after i ...

approximately a week after the necropsy, and was transported to Switzerland for treatment. She was discharged from hospital after two weeks and had fully recovered six weeks after the infection.

Ecology

The ecology of TAFV is currently unclear and no reservoir host has yet been identified. Therefore, it remains unclear how TAFV was introduced into the western chimpanzee population.

Bat Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...

s are suspected to harbor the virus because infectious

Marburg virus Marburg virus (MARV) is a hemorrhagic fever virus of the '' Filoviridae'' family of viruses and a member of the species '' Marburg marburgvirus'', genus '' Marburgvirus''. It causes Marburg virus disease in primates, a form of viral hemorrhag ...

(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

TAFV is basically uncharacterized on a molecular level. However, its genomic sequence, and with it the

genomic Genomics is an interdisciplinary field of molecular biology focusing on the structure, function, evolution, mapping, and editing of genomes. A genome is an organism's complete set of DNA, including all of its genes as well as its hierarchical, ...

organization and the conservation of individual

open reading frame In molecular biology, reading frames are defined as spans of DNA sequence between the start and stop codons. Usually, this is considered within a studied region of a prokaryotic DNA sequence, where only one of the six possible reading frames ...

s, is similar to that of the other four known ebolaviruses. It is therefore currently assumed that the knowledge obtained for EBOV can be extrapolated to TAFV and that all TAFV

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

s 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
{{DEFAULTSORT:Tai Forest Ebolavirus Animal viral diseases Arthropod-borne viral fevers and viral haemorrhagic fevers Biological agents Hemorrhagic fevers Ebolaviruses Zoonotic viral diseases Primate diseases Tropical diseases Virus-related cutaneous conditions