Asfarviridae
Encyclopedia
Asfarviridae is a family
of virus
es that primarily infects swine, resulting in an onset of African swine fever
. There is a single genus in this family: Asfivirus. The name of this family and genus are derived from the acronym: African swine fever and related viruses. Only a single species has been described to date for this genus.
This group of viruses are the only known arthropod borne DNA viruses. The viruses in this family are all enveloped and have double-stranded DNA genomes.
The Asfarvirus exhibits some similarities in genome structure and replication strategies to the poxviruses and phycodnaviruses
but has different virion structure from poxviruses and several other properties that distinguish it from the latter.
The genome is linear double stranded DNA and between 170 and 190 kilobases in length. Its guanine
+ cytosine
content is 39 %.
The virus can be grown in cell culture but cytopathic effects may be absent. Acidophilic, intracytoplasmic inclusion bodies may be visible in biopsies or post mortum material. Replication is cytoplasmic and the virons mature by budding from plasma membrane.
The viruses in this family infect domestic pig
s and their relatives. The natural hosts are warthogs (Phacochoerus africanus), bush pigs (Potamochoerus porcus) and argasid ticks (Ornithodoros
species). Young warthogs when infected develop a high viraemia and are infectious to ticks. Older warthogs are generally immune to infection. The virus can replicate within the ticks. Transtadial, transovarial and sexual spread within the ticks occurs.
During infection the virus the virions multiply in erythrocytes, endothelial cells and leukocytes and not in the epithelial cells. During infection the virus can be isolated from blood
, spleen
, visceral lymph node
s and tonsil
s.
Several species
are known none of which are able to infect humans.
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
of virus
Virus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...
es that primarily infects swine, resulting in an onset of African swine fever
African swine fever virus
African swine fever virus is the causative agent of African swine fever . ASFV is a large, double-stranded DNA virus which replicates in the cytoplasm of infected cells, and is the only member of the Asfarviridae family. ASFV infects domestic pigs, warthogs and bushpigs, as well as soft ticks ,...
. There is a single genus in this family: Asfivirus. The name of this family and genus are derived from the acronym: African swine fever and related viruses. Only a single species has been described to date for this genus.
This group of viruses are the only known arthropod borne DNA viruses. The viruses in this family are all enveloped and have double-stranded DNA genomes.
The Asfarvirus exhibits some similarities in genome structure and replication strategies to the poxviruses and phycodnaviruses
Phycodnaviridae
Phycodnaviruses are large , double stranded DNA viruses that infect marine or freshwater eukaryotic algae...
but has different virion structure from poxviruses and several other properties that distinguish it from the latter.
Virology
The virons consist of an envelope, a capsid, a core and a nucleoprotein complex. They are spherical and measure 175-215 nanometers (nm) in diameter. The capsid is icosahedral (T=189-217) with a diameter of 172-191 nm and appear hexagonal in outline. The capsomers measure 13 nm in diameter and there are 1892-2172 of these per capsid.The genome is linear double stranded DNA and between 170 and 190 kilobases in length. Its guanine
Guanine
Guanine is one of the four main nucleobases found in the nucleic acids DNA and RNA, the others being adenine, cytosine, and thymine . In DNA, guanine is paired with cytosine. With the formula C5H5N5O, guanine is a derivative of purine, consisting of a fused pyrimidine-imidazole ring system with...
+ cytosine
Cytosine
Cytosine is one of the four main bases found in DNA and RNA, along with adenine, guanine, and thymine . It is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached . The nucleoside of cytosine is cytidine...
content is 39 %.
The virus can be grown in cell culture but cytopathic effects may be absent. Acidophilic, intracytoplasmic inclusion bodies may be visible in biopsies or post mortum material. Replication is cytoplasmic and the virons mature by budding from plasma membrane.
The viruses in this family infect domestic pig
Pig
A pig is any of the animals in the genus Sus, within the Suidae family of even-toed ungulates. Pigs include the domestic pig, its ancestor the wild boar, and several other wild relatives...
s and their relatives. The natural hosts are warthogs (Phacochoerus africanus), bush pigs (Potamochoerus porcus) and argasid ticks (Ornithodoros
Ornithodoros
Ornithodoros is a genus in the soft-bodied tick family, Argasidae. The Linnean name derives from ornithos and doros , meaning "bird" and "gift," respectively...
species). Young warthogs when infected develop a high viraemia and are infectious to ticks. Older warthogs are generally immune to infection. The virus can replicate within the ticks. Transtadial, transovarial and sexual spread within the ticks occurs.
During infection the virus the virions multiply in erythrocytes, endothelial cells and leukocytes and not in the epithelial cells. During infection the virus can be isolated from blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
, spleen
Spleen
The spleen is an organ found in virtually all vertebrate animals with important roles in regard to red blood cells and the immune system. In humans, it is located in the left upper quadrant of the abdomen. It removes old red blood cells and holds a reserve of blood in case of hemorrhagic shock...
, visceral lymph node
Lymph node
A lymph node is a small ball or an oval-shaped organ of the immune system, distributed widely throughout the body including the armpit and stomach/gut and linked by lymphatic vessels. Lymph nodes are garrisons of B, T, and other immune cells. Lymph nodes are found all through the body, and act as...
s and tonsil
Tonsil
Palatine tonsils, occasionally called the faucial tonsils, are the tonsils that can be seen on the left and right sides at the back of the throat....
s.
Several species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
are known none of which are able to infect humans.