Caliciviridae
Encyclopedia
The Caliciviridae family are a family of viruses, members of Class IV of the Baltimore scheme. They are positive-sense, single stranded RNA
which is non-segmented. The caliciviruses have been found in a number of organisms such as humans, cattle
, pig
s, cats
, chicken
s, reptile
s, dolphin
s and amphibian
s. The caliciviruses have a simple construction and are not enveloped
. The capsid
appears hexagonal/spherical and has icosahedral symmetry with a diameter of 35-39 nm.
Caliciviruses are not very well studied because they do not grow in culture
and there is no suitable animal model. However, the recent application of modern genomic technologies has led to an increased understanding of the virus family. The viral genome
has been sequenced.
The name calicivirus is derived from the Latin word calyx meaning cup or goblet. This name is appropriate as many strains have visible cup-shaped depressions.
The Caliciviridae family include the following genera:
Australia and New Zealand, in an effort to control their rabbit populations, have intentionally spread calicivirus.
, which is the inflammation
of the stomach
and intestine
s. Symptoms can include vomiting
and diarrhea
. These symptoms emerge after an incubation time of 2 days and the symptoms only generally last for 3 days. Most calicivirus infections do not call for medical attention, but those who are immunocompromised may need to be hospitalized for rehydration therapy.
(FCV) represents an important pathogen of cats. Sapovirus
, Norovirus and Vesivirus
have been detected in pigs, making this animal species of particular interest in the study of calicivirus pathogenesis and host range. The first mouse norovirus, murine norovirus 1 (MNV-1), was discovered in 2003. Since then, numerous murine norovirus strains have been identified and they were assigned a new genogroup in the genus Norovirus. Rabbit hemorrhagic disease virus (RHDV) is a pathogen of rabbits that causes major problems throughout the world where rabbits are reared for food and clothing, make a significant contribution to ecosystem ecology, and where they support valued wildlife as a food source.
RNA
Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....
which is non-segmented. The caliciviruses have been found in a number of organisms such as humans, cattle
Cattle
Cattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...
, 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, cats
Feline calicivirus
Feline calicivirus is a virus of the family Caliciviridae that causes disease in cats. It is one of the two important viral causes of respiratory infection in cats, the other being feline herpesvirus. FCV can be isolated from about 50 percent of cats with upper respiratory infection...
, chicken
Chicken
The chicken is a domesticated fowl, a subspecies of the Red Junglefowl. As one of the most common and widespread domestic animals, and with a population of more than 24 billion in 2003, there are more chickens in the world than any other species of bird...
s, reptile
Reptile
Reptiles are members of a class of air-breathing, ectothermic vertebrates which are characterized by laying shelled eggs , and having skin covered in scales and/or scutes. They are tetrapods, either having four limbs or being descended from four-limbed ancestors...
s, dolphin
Dolphin
Dolphins are marine mammals that are closely related to whales and porpoises. There are almost forty species of dolphin in 17 genera. They vary in size from and , up to and . They are found worldwide, mostly in the shallower seas of the continental shelves, and are carnivores, mostly eating...
s and amphibian
Amphibian
Amphibians , are a class of vertebrate animals including animals such as toads, frogs, caecilians, and salamanders. They are characterized as non-amniote ectothermic tetrapods...
s. The caliciviruses have a simple construction and are not enveloped
Viral envelope
Many viruses have viral envelopes covering their protein capsids. The envelopes typically are derived from portions of the host cell membranes , but include some viral glycoproteins. Functionally, viral envelopes are used to help viruses enter host cells...
. The capsid
Capsid
A capsid is the protein shell of a virus. It consists of several oligomeric structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or may not correspond to individual proteins, are called capsomeres. The capsid encloses the genetic...
appears hexagonal/spherical and has icosahedral symmetry with a diameter of 35-39 nm.
Caliciviruses are not very well studied because they do not grow in culture
Culture
Culture is a term that has many different inter-related meanings. For example, in 1952, Alfred Kroeber and Clyde Kluckhohn compiled a list of 164 definitions of "culture" in Culture: A Critical Review of Concepts and Definitions...
and there is no suitable animal model. However, the recent application of modern genomic technologies has led to an increased understanding of the virus family. The viral 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....
has been sequenced.
The name calicivirus is derived from the Latin word calyx meaning cup or goblet. This name is appropriate as many strains have visible cup-shaped depressions.
The Caliciviridae family include the following genera:
- Genus VesivirusVesivirusThe genus vesivirus is in the Caliciviridae family of viruses. It includes feline calicivirus,San Miguel sealion virus, and vesicular exanthema of swine virus.-Morphology:...
; type species: Vesicular exanthema of swine virusVesicular exanthema of swine virusVesicular exanthema of swine virus is a virus different from those causing Foot-and-Mouth Disease and Swine Vesicular Disease but it produces a disease in pigs that is clinically indistinguishable from FMD and SVD... - Genus LagovirusLagovirus-Morphology:Virions consist of a capsid. Virus capsid is not enveloped, round with icosahedral symmetry. The isometric capsid has a diameter of 35-39 nm. Capsids appear round to hexagonal in outline. The capsid surface structure reveals a regular pattern with distinctive features. The capsomer...
; type species: Rabbit hemorrhagic disease virus - Genus Norovirus; type species: Norwalk virus
- Genus SapovirusSapovirusSapoviruses are caliciviruses that together with the noroviruses, are the most common cause of acute viral gastroenteritis in adults. The type species is Sapporo virus...
; type species: Sapporo virus
Australia and New Zealand, in an effort to control their rabbit populations, have intentionally spread calicivirus.
Transmission
Transmission of caliciviruses is generally by the fecal-oral route, but they can also be transmitted via the respiratory route.Human disease
Calicivirus infections commonly cause acute gastroenteritisGastroenteritis
Gastroenteritis is marked by severe inflammation of the gastrointestinal tract involving both the stomach and small intestine resulting in acute diarrhea and vomiting. It can be transferred by contact with contaminated food and water...
, which is the inflammation
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
of the stomach
Stomach
The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...
and intestine
Intestine
In human anatomy, the intestine is the segment of the alimentary canal extending from the pyloric sphincter of the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine...
s. Symptoms can include vomiting
Vomiting
Vomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...
and diarrhea
Diarrhea
Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...
. These symptoms emerge after an incubation time of 2 days and the symptoms only generally last for 3 days. Most calicivirus infections do not call for medical attention, but those who are immunocompromised may need to be hospitalized for rehydration therapy.
Animal viruses
Feline calicivirusFeline calicivirus
Feline calicivirus is a virus of the family Caliciviridae that causes disease in cats. It is one of the two important viral causes of respiratory infection in cats, the other being feline herpesvirus. FCV can be isolated from about 50 percent of cats with upper respiratory infection...
(FCV) represents an important pathogen of cats. Sapovirus
Sapovirus
Sapoviruses are caliciviruses that together with the noroviruses, are the most common cause of acute viral gastroenteritis in adults. The type species is Sapporo virus...
, Norovirus and Vesivirus
Vesivirus
The genus vesivirus is in the Caliciviridae family of viruses. It includes feline calicivirus,San Miguel sealion virus, and vesicular exanthema of swine virus.-Morphology:...
have been detected in pigs, making this animal species of particular interest in the study of calicivirus pathogenesis and host range. The first mouse norovirus, murine norovirus 1 (MNV-1), was discovered in 2003. Since then, numerous murine norovirus strains have been identified and they were assigned a new genogroup in the genus Norovirus. Rabbit hemorrhagic disease virus (RHDV) is a pathogen of rabbits that causes major problems throughout the world where rabbits are reared for food and clothing, make a significant contribution to ecosystem ecology, and where they support valued wildlife as a food source.