An RNA virus is a virus—other than a retrovirus—that has ribonucleic acid (RNA) as its genetic material. The nucleic acid is usually single-stranded RNA (ssRNA) but it may be double-stranded (dsRNA). Notable human diseases caused by RNA viruses include the common cold, influenza, SARS, MERS, COVID-19, Dengue Virus, hepatitis C, hepatitis E, West Nile fever, Ebola virus disease, rabies, polio, mumps, and measles.
Flaviviridae is a family of enveloped positive-strand RNA viruses which mainly infect mammals and birds. They are primarily spread through arthropod vectors. The family gets its name from the yellow fever virus; flavus is Latin for "yellow", and yellow fever in turn was named because of its propensity to cause jaundice in victims. There are 89 species in the family divided among four genera. Diseases associated with the group include: hepatitis (hepaciviruses), hemorrhagic syndromes, fatal mucosal disease (pestiviruses), hemorrhagic fever, encephalitis, and the birth defect microcephaly (flaviviruses).
Virus classification is the process of naming viruses and placing them into a taxonomic system similar to the classification systems used for cellular organisms.
Hepadnaviridae is a family of viruses. Humans, apes, and birds serve as natural hosts. There are currently 18 species in this family, divided among 5 genera. Its best-known member is hepatitis B virus. Diseases associated with this family include: liver infections, such as hepatitis, hepatocellular carcinomas, and cirrhosis. It is the sole accepted family in the order Blubervirales.
Picornaviruses are a group of related nonenveloped RNA viruses which infect vertebrates including fish, mammals, and birds. They are viruses that represent a large family of small, positive-sense, single-stranded RNA viruses with a 30 nm icosahedral capsid. The viruses in this family can cause a range of diseases including the common cold, poliomyelitis, meningitis, hepatitis, and paralysis.
Rubella virus (RuV) is the pathogenic agent of the disease rubella, transmitted only between humans via the respiratory route, and is the main cause of congenital rubella syndrome when infection occurs during the first weeks of pregnancy.
Birnaviridae is a family of double-stranded RNA viruses. Salmonid fish, birds and insects serve as natural hosts. There are currently 11 species in this family, divided among seven genera. Diseases associated with this family include infectious pancreatic necrosis in salmonid fish, which causes significant losses to the aquaculture industry, with chronic infection in adult salmonid fish and acute viral disease in young salmonid fish.
Dicistroviridae is a family of viruses in the order Picornavirales. Invertebrates, including aphids, leafhoppers, flies, bees, ants, and silkworms, serve as natural hosts. There are 15 species in this family, assigned to three genera. Diseases associated with this family include: DCV: increased reproductive potential. extremely pathogenic when injected with high associated mortality. CrPV: paralysis and death.
Fiersviridae is a family of positive-strand RNA viruses which infect prokaryotes. Bacteria serve as the natural host. They are small viruses with linear, positive-sense, single-stranded RNA genomes that encode four proteins. All phages of this family require bacterial pili to attach to and infect cells. The family has 185 genera, most discovered by metagenomics. In 2020, the family was renamed from Leviviridae to its current name.
Potyviridae is a family of positive-strand RNA viruses that encompasses more than 30% of known plant viruses, many of which are of great agricultural significance. The family has 12 genera and 235 species, three of which are unassigned to a genus.
Potyvirus is a genus of positive-strand RNA viruses in the family Potyviridae. Plants serve as natural hosts. Like begomoviruses, members of this genus may cause significant losses in agricultural, pastoral, horticultural, and ornamental crops. More than 200 species of aphids spread potyviruses, and most are from the subfamily Aphidinae. The genus contains 190 species and potyviruses account for about thirty percent of all currently known plant viruses.
Cardiovirus are a group of viruses within order Picornavirales, family Picornaviridae. Vertebrates serve as natural hosts for these viruses.
Kakugo virus is a picorna-like virus most commonly found in the brains of worker bees. It is a subtype of the Deformed wing virus. The Kakugo virus, when resident in a bee's brain, can contribute to aggressive behaviors similar to those preeminent during a bee's guard phase in their life cycle. Kakugo is the first virus to have been found to cause aggressive behavior, although because the virus was only recently discovered to have such effects, research into the matter is limited.
Deformed wing virus (DWV) is an RNA virus, one of 22 known viruses affecting honey bees. While most commonly infecting the honey bee, Apis mellifera, it has also been documented in other bee species, like Bombus terrestris, thus, indicating it may have a wider host specificity than previously anticipated. The virus was first isolated from a sample of symptomatic honeybees from Japan in the early 1980s and is currently distributed worldwide. It is found also in pollen baskets and commercially reared bumblebees. Its main vector in A. mellifera is the Varroa mite. It is named after what is usually the most obvious deformity it induces in the development of a honeybee pupa, which is shrunken and deformed wings, but other developmental deformities are often present.
Erbovirus is a genus of viruses in the order Picornavirales, in the family Picornaviridae. Horses serve as natural hosts. There is only one species in this genus: Erbovirus A. Diseases associated with this genus include: upper respiratory tract disease with viremia and fecal shedding. Viruses belonging to the genus Erbovirus have been isolated in horses with acute upper febrile respiratory disease. The structure of the Erbovirus virion is icosahedral, having a diameter of 27–30 nm.
Teschovirus is a genus of viruses in the order Picornavirales, in the family Picornaviridae. Pigs serve as natural hosts. There are two species in this genus, including Teschovirus A, which is responsible for the porcine enteroviral encephalomyelitis disease caused in pigs. The genus name comes from this species and the disease it causes: Teschen disease, which itself was named for the town Teschen in Poland/Czechoslovakia where the disease was first recognised in 1929.
Strawberry mottle virus (SMV) is a pathogenic plant virus in Secoviridae, a family of plant-infecting picornaviruses. It is not yet assigned to a genus. Virions are isometric, approximately 28 nm in diameter, and contain two RNA strands (RNA1 and RNA2) equal to about 12,600 nucleotides in length. The polyprotein of RNA1 contains regions identified as helicase, protease, RNA-dependent RNA polymerase and a viral genome-linked protein while RNA2 shows similarities to the large coat protein domain of the Satsuma dwarf virus.
Marnaviridae is a family of positive-stranded RNA viruses in the order Picornavirales that infect various photosynthetic marine protists. Members of the family have non-enveloped, icosahedral capsids. Replication occurs in the cytoplasm and causes lysis of the host cell. The first species of this family that was isolated is Heterosigma akashiwo RNA virus (HaRNAV) in the genus Marnavirus, which infects the toxic bloom-forming Raphidophyte alga, Heterosigma akashiwo. As of 2021, there are twenty species across seven genera in this family, as well as many other related virus sequences discovered through metagenomic sequencing that are currently unclassified.
The black queen cell virus (BQCV) is a virus that infects honey bees, specifically Apis mellifera, Apis florea, and Apis dorsata. Infection of the latter two species is more recent and can be attributed to genetic similarity and geographical closeness. It is important to learn about this virus because it is one of the most common bee viruses and bees are the most important pollinators. The agricultural industry depends on the bee's pollination to increase its economic value.
In virology, realm is the highest taxonomic rank established for viruses by the International Committee on Taxonomy of Viruses (ICTV), which oversees virus taxonomy. Six virus realms are recognized and united by specific highly conserved traits:
