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Flaviviridae
''Flaviviridae'' is a family of Viral envelope, enveloped positive-strand RNA viruses which mainly infect mammals and birds. They are primarily spread through arthropod vector (epidemiology), vectors (mainly ticks and mosquitoes). 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), Bleeding, hemorrhagic syndromes, Bovine viral diarrhea, fatal mucosal disease (pestiviruses), Viral hemorrhagic fever, hemorrhagic fever, encephalitis, and the birth defect microcephaly (flaviviruses). Structure Virus particles are enveloped and spherical with icosahedral-like geometries that have pseudo T=3 symmetry. They are about 40–60 nanometer, nm in diameter. Genome Members of the family ''Flaviviridae'' have monopartite, linear, single ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pegivirus
''Pegivirus'' is a genus of single positive-stranded RNA viruses in the family ''Flaviviridae''. The name is a derived one: "Pe" stands for "persistent" and "g" is a reference to GB virus C, Hepatitis G, a former name of the ''C'' species. Taxonomy Eleven named species are within the genus ''Pegivirus''. Isolates belonging to the species ''Pegivirus C'' are monophyletic and show 50% nucleotide (>55% amino acid) divergence from other members of this genus. Pegiviruses assigned to this species (''Pegivirus A'') originate from primate host species (humans, chimpanzees and several New World monkey species). The sequence U22303 has been assigned as the type member of the species, as this was the first pegivirus to be described for this species. Terminology to describe viruses with different hosts has not been approved by the International Committee on Taxonomy of Viruses; however, ''Pegivirus A'' viruses have been called HPgV for human pegivirus, SPgV for new world simian pegivirus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flavivirus
''Flavivirus'', renamed ''Orthoflavivirus'' in 2023, is a genus of positive-strand RNA viruses in the family ''Flaviviridae''. The genus includes the West Nile virus, dengue virus, tick-borne encephalitis virus, yellow fever virus, Zika virus and several other viruses which may cause encephalitis, as well as insect-specific flaviviruses (ISFs) such as cell fusing agent virus (CFAV), Palm Creek virus (PCV), and Parramatta River virus (PaRV). While dual-host flaviviruses can infect vertebrates as well as arthropods, insect-specific flaviviruses are restricted to their competent arthropods. The means by which flaviviruses establish persistent infection in their competent vectors and cause disease in humans depends upon several virus-host interactions, including the intricate interplay between flavivirus-encoded immune antagonists and the host antiviral innate immune effector molecules. Flaviviruses are named for the yellow fever virus; the word ''flavus'' means 'yellow' in Lat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepacivirus
''Hepacivirus'' is a genus of positive-strand RNA viruses in the family ''Flaviviridae''. The hepatitis C virus (HCV), in species ''Hepacivirus hominis'', infects humans and is associated with hepatitis and hepatocellular carcinoma. There are fourteen species in the genus which infect a range of other vertebrate. History Hepatitis C virus (HCV), which is the causative agent of hepatitis C in humans, and a member of the species ''Hepacivirus C'', was discovered in 1989. Eight genotypes (1–8) and eighty-six subtypes (1a, 1b etc.) of hepatitis C virus have been named. GBV-B virus (also known as GB virus B) discovered in 1995 is capable of infecting New World monkeys, in particular tamarins. Like HCV it is transmitted by the blood-borne route and similar to HCV it is associated with the viral hepatitis. However GBV-B has never been identified in wild animals and its natural host is not known. Structure Viruses in the genus ''Hepacivirus'' are enveloped and have spherical icosahe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pestivirus
''Pestivirus'' is a genus of viruses, in the family ''Flaviviridae''. Viruses in the genus ''Pestivirus'' infect mammals, including members of the family Bovidae (which includes cattle, sheep, and goats) and the family Suidae (which includes various species of swine). There are 19 species in this genus. Diseases associated with this genus include: hemorrhagic syndromes, abortion, and fatal mucosal disease. Structure Viruses in ''Pestivirus'' are enveloped, with spherical geometries. Their diameter is around 50 nm. Genomes are linear and not segmented, around 12kb in length. Lifecycle Entry into the host cell is achieved by attachment of the viral envelope protein E2 to host receptors, which mediates clathrin-mediated endocytosis. The main viral replication process happens in host cytoplasm. Replication follows the positive strand RNA virus replication model. An IRES RNA element at the 5'-nontranslated region (NTR) of the viral genome recruits viral and cellular transl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bovine Viral Diarrhea
Bovine viral diarrhea (BVD), bovine viral diarrhoea (UK English) or mucosal disease, previously referred to as bovine virus diarrhea (BVD), is an economically significant disease of cattle Cattle (''Bos taurus'') are large, domesticated, bovid ungulates widely kept as livestock. They are prominent modern members of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Mature female cattle are calle ... that is found in the majority of countries throughout the world. Worldwide reviews of the economically assessed production losses and intervention programs (e.g. eradication programs, vaccination strategies and biosecurity measures) incurred by BVD infection have been published. The causative agent, bovine viral diarrhea virus (BVDV), is a member of the genus '' Pestivirus'' of the family Flaviviridae. BVD infection results in a wide variety of clinical signs, due to its immunosuppressive effects, as well as having a direct effect on respirato ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zika Virus
Zika virus (ZIKV; pronounced or ) is a member of the virus family ''Flaviviridae''. It is spread by daytime-active ''Aedes'' mosquitoes, such as '' A. aegypti'' and '' A. albopictus''. Its name comes from the Ziika Forest of Uganda, where the virus was first isolated in 1947. Zika virus shares a genus with the dengue, yellow fever, Japanese encephalitis, and West Nile viruses. Since the 1950s, it has been known to occur within a narrow equatorial belt from Africa to Asia. From 2007 to , the virus spread eastward, across the Pacific Ocean to the Americas, leading to the 2015–2016 Zika virus epidemic. The infection, known as Zika fever or Zika virus disease, often causes no or only mild symptoms, similar to a very mild form of dengue fever. While there is no specific treatment, paracetamol (acetaminophen) and rest may help with the symptoms. Zika can spread from a pregnant woman to her baby. This can result in microcephaly, severe brain malformations, and other b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viral Hemorrhagic Fever
Viral hemorrhagic fevers (VHFs) are a diverse group of diseases. "Viral" means a health problem caused by infection from a virus, " hemorrhagic" means to bleed, and "fever" means an unusually high body temperature. Bleeding and fever are common signs of VHFs, which is how the group of infections got its common name. There are five known families of RNA viruses which cause VHFs: '' Arenaviridae'', '' Filoviridae'', '' Flaviviridae'', '' Hantaviridae'', and ''Rhabdoviridae''. Some VHFs are usually mild, such as nephropathia epidemica (within the family ''Hantaviridae''). But some are usually severe and have a high death rate, such as Ebola virus (within the family ''Filoviridae''). All VHFs can potentially cause severe blood loss, high fever, and death. Both humans and non human animals can be infected. Signs and symptoms The following are signs and symptoms of most or all VHFs. * Circulatory shock *Diarrhea (feces which resemble more liquid than solid) *Headache *Hypotens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viral Envelope
A viral envelope is the outermost layer of many types of viruses. It protects the genetic material in their life cycle when traveling between host cells. Not all viruses have envelopes. A viral envelope protein or E protein is a protein in the envelope, which may be acquired by the capsid from an infected host cell. Host cell infection process Numerous human pathogenic viruses in circulation are encased in lipid bilayers, and they infect their target cells by causing the viral envelope and cell membrane to fuse. Although there are effective vaccines against some of these viruses, there is no preventative or curative medicine for the majority of them. In most cases, the known vaccines operate by inducing antibodies that prevent the pathogen from entering cells. This happens in the case of enveloped viruses when the antibodies bind to the viral envelope proteins. The membrane fusion event that triggers viral entrance is caused by the viral membrane fusion protein. Many envelo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Encephalitis
Encephalitis is inflammation of the Human brain, brain. The severity can be variable with symptoms including reduction or alteration in consciousness, aphasia, headache, fever, confusion, a stiff neck, and vomiting. Complications may include seizures, hallucinations, trouble speaking, memory problems, and problems with hearing. Causes of encephalitis include viruses such as herpes simplex virus and rabies virus as well as bacteria, fungi, or parasites. Other causes include autoimmune diseases and certain medications. In many cases the cause remains unknown. Risk factors include a immunosuppression, weak immune system. Diagnosis is typically based on symptoms and supported by blood tests, medical imaging, and analysis of cerebrospinal fluid. Certain types are preventable with vaccines. Treatment may include antiviral medications (such as acyclovir), anticonvulsants, and corticosteroids. Treatment generally takes place in hospital. Some people require artificial respiration. Once ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
