Ravn virus
Encyclopedia
Ravn virus is a close relative of the much more commonly known Marburg virus (MARV)
. RAVV causes severe disease
in human
s and (experimentally) in nonhuman primates in the form of viral hemorrhagic fever
. RAVV is a Select Agent
, World Health Organization
Risk Group 4 Pathogen (requiring Biosafety Level 4-equivalent containment
), National Institutes of Health
/National Institute of Allergy and Infectious Diseases
Category A Priority Pathogen, Centers for Disease Control and Prevention
Category A Bioterrorism Agent
, and listed as a Biological Agent for Export Control by the Australia Group
.
Marburg marburgvirus
, which is included into the genus
Marburgvirus
, family
Filoviridae
, order
Mononegavirales
. The name Ravn virus is derived from Ravn (the name of the Danish patient from whom this virus was first isolated) and the taxonomic
suffix
virus.
(ICTV), the name Ravn virus is always to be capitalized
, but is never italicized
, and may be abbreviated
(with RAVV being the official abbreviation).
is a Ravn virus if it has the properties of Marburg marburgviruses
and if its genome
diverges from that of the prototype Marburg marburgvirus, Marburg virus variant Musoke (MARV/Mus), by ≥10% but from that of the prototype Ravn virus (variant Ravn) by <10% at the nucleotide
level.
organization and the conservation of individual open reading frame
s, is similar to that of Marburg virus. It is therefore currently assumed that the knowledge obtained for MARV can be extrapolated
to RAVV and that all RAVV protein
s behave analogous to those of MARV.
. This isolation, together with the isolation of infectious MARV, strongly suggests that Old World
fruit bat
s are involved in the natural maintenance of marburgviruses. Further studies are necessary to establish whether Egyptian rousettes are the actual hosts of RAVV and MARV or whether they get infected via contact with another animal and therefore serve only as intermediate hosts.
Marburg virus
Marburg virus disease is the name for the human disease caused by any of the two marburgviruses Marburg virus and Ravn virus...
. RAVV causes severe disease
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
in human
Human
Humans are the only living species in the Homo genus...
s and (experimentally) in nonhuman primates in the form of viral hemorrhagic fever
Viral hemorrhagic fever
The viral hemorrhagic fevers are a diverse group of animal and human illnesses that are caused by four distinct families of RNA viruses: the families Arenaviridae, Filoviridae, Bunyaviridae, and Flaviviridae. All types of VHF are characterized by fever and bleeding disorders and all can progress...
. RAVV is a Select Agent
Select agent
In United States law, Select Agents are pathogens or biological toxins which have been declared by the U.S. Department of Health and Human Services or by the U.S. Department of Agriculture to have the "potential to pose a severe threat to public health and safety"...
, World Health Organization
World Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...
Risk Group 4 Pathogen (requiring Biosafety Level 4-equivalent containment
Biosafety
Biosafety: prevention of large-scale loss of biological integrity, focusing both on ecology and human health .Biosafety is related to several fields:*In ecology ,...
), National Institutes of Health
National Institutes of Health
The National Institutes of Health are an agency of the United States Department of Health and Human Services and are the primary agency of the United States government responsible for biomedical and health-related research. Its science and engineering counterpart is the National Science Foundation...
/National Institute of Allergy and Infectious Diseases
National Institute of Allergy and Infectious Diseases
The National Institute of Allergy and Infectious Diseases is one of the 27 institutes and centers that make up the National Institutes of Health , an agency of the United States Department of Health and Human Services...
Category A Priority Pathogen, Centers for Disease Control and Prevention
Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention are a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta...
Category A Bioterrorism Agent
Bioterrorism
Bioterrorism is terrorism involving the intentional release or dissemination of biological agents. These agents are bacteria, viruses, or toxins, and may be in a naturally occurring or a human-modified form. For the use of this method in warfare, see biological warfare.-Definition:According to the...
, and listed as a Biological Agent for Export Control by the Australia Group
Australia Group
The Australia Group is an informal group of countries established in 1985 to help member countries to identify those of their exports which need to be controlled so as not to contribute to the spread of chemical and biological weapons .The group, initially consisting of 15 members, held its first...
.
Use of term
Ravn virus (abbreviated RAVV) was first described in 1996. Today, the virus is one of two members of the speciesInternational Committee on Taxonomy of Viruses
The International Committee on Taxonomy of Viruses is a committee which authorizes and organizes the taxonomic classification of viruses. They have developed a universal taxonomic scheme for viruses and aim to describe all the viruses of living organisms. Members of the committee are considered to...
Marburg marburgvirus
Marburg marburgvirus
The species Marburg marburgvirus is the taxonomic home of two related viruses that form filamentous virions, Marburg virus and Ravn virus...
, which is included into the genus
International Committee on Taxonomy of Viruses
The International Committee on Taxonomy of Viruses is a committee which authorizes and organizes the taxonomic classification of viruses. They have developed a universal taxonomic scheme for viruses and aim to describe all the viruses of living organisms. Members of the committee are considered to...
Marburgvirus
Marburgvirus
The genus Marburgvirus is the taxonomic home of one species whose members are two related viruses that form filamentous virions, Marburg virus and Ravn virus...
, family
International Committee on Taxonomy of Viruses
The International Committee on Taxonomy of Viruses is a committee which authorizes and organizes the taxonomic classification of viruses. They have developed a universal taxonomic scheme for viruses and aim to describe all the viruses of living organisms. Members of the committee are considered to...
Filoviridae
Filoviridae
The family Filoviridae is the taxonomic home of several related viruses that form filamentous virions. Two members of the family that are commonly known are Ebola virus and Marburg virus. Both viruses, and some of their lesser known relatives, cause severe disease in humans and nonhuman primates in...
, order
International Committee on Taxonomy of Viruses
The International Committee on Taxonomy of Viruses is a committee which authorizes and organizes the taxonomic classification of viruses. They have developed a universal taxonomic scheme for viruses and aim to describe all the viruses of living organisms. Members of the committee are considered to...
Mononegavirales
Mononegavirales
The order Mononegavirales is the taxonomic home of numerous related viruses. Members of the order that are commonly known are, for instance, Ebola virus, human respiratory syncytial virus, measles virus, mumps virus, Nipah virus, and rabies virus. All of these viruses cause significant disease in...
. The name Ravn virus is derived from Ravn (the name of the Danish patient from whom this virus was first isolated) and the taxonomic
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
suffix
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 or adjectives, and verb endings, which form the conjugation of verbs...
virus.
Note
Ravn virus is pronounced rævn vɑɪrəs (IPA) or ra-vuhn vahy-ruhs in English phonetic notation. According to the rules for taxon naming established by the International Committee on Taxonomy of VirusesInternational Committee on Taxonomy of Viruses
The International Committee on Taxonomy of Viruses is a committee which authorizes and organizes the taxonomic classification of viruses. They have developed a universal taxonomic scheme for viruses and aim to describe all the viruses of living organisms. Members of the committee are considered to...
(ICTV), the name Ravn virus is always to be capitalized
Capitalization
Capitalization is writing a word with its first letter as a majuscule and the remaining letters in minuscules . This of course only applies to those writing systems which have a case distinction...
, but is never italicized
Italic type
In typography, italic type is a cursive typeface based on a stylized form of calligraphic handwriting. Owing to the influence from calligraphy, such typefaces often slant slightly to the right. Different glyph shapes from roman type are also usually used—another influence from calligraphy...
, and may be abbreviated
Abbreviation
An abbreviation is a shortened form of a word or phrase. Usually, but not always, it consists of a letter or group of letters taken from the word or phrase...
(with RAVV being the official abbreviation).
Previous designations
Ravn virus was first introduced as a new "subtype" of Marburg virus in 1996.. In 2006, a thorough whole-genome analysis of all marburgviruses revealed the existence of five distinct genetic lineages. The genomes of representative isolates of four of those lineages differed from each other by only 0-7.8% on the nucleotide level, whereas representatives of the fifth lineage, including the new "subtype", differed from those of the other lineages by up to 21.3%. Consequently, the fifth genetic lineage was reclassified as a virus, Ravn virus (RAVV), distinct from the virus represented by the four more closely related lineages, Marburg virus (MARV).Virus inclusion criteria
A virus that fulfills the criteria for being a member of the species Marburg marburgvirusMarburg marburgvirus
The species Marburg marburgvirus is the taxonomic home of two related viruses that form filamentous virions, Marburg virus and Ravn virus...
is a Ravn virus if it has the properties of Marburg marburgviruses
Marburg marburgvirus
The species Marburg marburgvirus is the taxonomic home of two related viruses that form filamentous virions, Marburg virus and Ravn virus...
and if its genome
Genome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....
diverges from that of the prototype Marburg marburgvirus, Marburg virus variant Musoke (MARV/Mus), by ≥10% but from that of the prototype Ravn virus (variant Ravn) by <10% at the nucleotide
Nucleotide
Nucleotides are molecules that, when joined together, make up the structural units of RNA and DNA. In addition, nucleotides participate in cellular signaling , and are incorporated into important cofactors of enzymatic reactions...
level.
Disease
RAVV is one of two marburgviruses that causes Marburg virus disease (MVD) in humans (in the literature also often referred to as Marburg hemorrhagic fever, MHF). MVD due to RAVV infection cannot be differentiated from MVD caused by MARV by clinical observation alone, which is why the clinical presentation and pathology of infections by all marburgviruses is presented together on a separate page (see Marburg virus disease (MVD)). In the past, RAVV has caused the following MVD outbreaks:| Year | Geographic location | Human cases/deaths (case-fatality rate) |
| 1987 | Kenya Kenya Kenya , officially known as the Republic of Kenya, is a country in East Africa that lies on the equator, with the Indian Ocean to its south-east... |
1/1 (100%) |
| 1998-2000 | Durba and Watsa Watsa Watsa is a community in Province Orientale of the Democratic Republic of the Congo, administrative center of the Watsa Territory.Watsa was the location of the VI battalion of the Force Publique in the 1940s and 1950s.... , Democratic Republic of the Congo Democratic Republic of the Congo The Democratic Republic of the Congo is a state located in Central Africa. It is the second largest country in Africa by area and the eleventh largest in the world... |
? (A total of 154 cases and 128 deaths of marburgvirus infection were recorded during this outbreak. The case fatality was 83%. Two different marburgviruses, RAVV and Marburg virus (MARV), cocirculated and caused disease. It has never been published how many cases and deaths were due to RAVV or MARV infection) |
| 2007 | Uganda Uganda Uganda , officially the Republic of Uganda, is a landlocked country in East Africa. Uganda is also known as the "Pearl of Africa". It is bordered on the east by Kenya, on the north by South Sudan, on the west by the Democratic Republic of the Congo, on the southwest by Rwanda, and on the south by... |
1/0 (0%) |
Virology
RAVV is basically uncharacterized on a molecular level. However, its genomic sequence, and with it the genomicGenome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....
organization and the conservation of individual open reading frame
Open reading frame
In molecular genetics, an open reading frame is a DNA sequence that does not contain a stop codon in a given reading frame.Normally, inserts which interrupt the reading frame of a subsequent region after the start codon cause frameshift mutation of the sequence and dislocate the sequences for stop...
s, is similar to that of Marburg virus. It is therefore currently assumed that the knowledge obtained for MARV can be extrapolated
Extrapolation
In mathematics, extrapolation is the process of constructing new data points. It is similar to the process of interpolation, which constructs new points between known points, but the results of extrapolations are often less meaningful, and are subject to greater uncertainty. It may also mean...
to RAVV and that all RAVV protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
s behave analogous to those of MARV.
Ecology
In 2009, the successful isolation of infectious RAVV was reported from caught healthy Egyptian rousettes Rousettus aegyptiacus)Egyptian fruit bat
The Egyptian Fruit Bat or Egyptian Rousette is a species of Old World fruit bat found throughout Africa, except in the desert regions of the Sahara, and throughout the Middle East, as far east as Pakistan and northern India...
. This isolation, together with the isolation of infectious MARV, strongly suggests that Old World
Old World
The Old World consists of those parts of the world known to classical antiquity and the European Middle Ages. It is used in the context of, and contrast with, the "New World" ....
fruit bat
Bat
Bats are mammals of the order Chiroptera "hand" and pteron "wing") whose forelimbs form webbed wings, making them the only mammals naturally capable of true and sustained flight. By contrast, other mammals said to fly, such as flying squirrels, gliding possums, and colugos, glide rather than fly,...
s are involved in the natural maintenance of marburgviruses. Further studies are necessary to establish whether Egyptian rousettes are the actual hosts of RAVV and MARV or whether they get infected via contact with another animal and therefore serve only as intermediate hosts.
Popular culture
- In the non-fiction thriller, The Hot ZoneThe Hot ZoneThe Hot Zone is a best-selling 1994 non-fiction bio-thriller by Richard Preston about the origins and incidents involving viral hemorrhagic fevers, particularly ebolaviruses and marburgviruses...
, Richard PrestonRichard PrestonRichard Preston, born August 5, 1954 in Cambridge, Massachusetts, U.S., is a New Yorker writer and bestselling author perhaps best-known for his books about infectious disease epidemics and bioterrorism, although he has written other non-fiction works...
describes the first case of RAVV infection in the Danish boy Preston calls "Peter Cardinal"