|
Enteroviruses
''Enterovirus'' is a genus of positive-sense single-stranded RNA viruses associated with several human and mammalian diseases. Enteroviruses are named by their transmission-route through the intestine ('enteric' meaning intestinal). Serologic studies have distinguished 71 human enterovirus serotypes on the basis of antibody neutralization tests. Additional antigenic variants have been defined within several of the serotypes on the basis of reduced or nonreciprocal cross-neutralization between variant strains. On the basis of their pathogenesis in humans and animals, the enteroviruses were originally classified into four groups, polioviruses, Coxsackie A viruses (CA), Coxsackie B viruses (CB), and echoviruses, but it was quickly realized that there were significant overlaps in the biological properties of viruses in the different groups. Enteroviruses isolated more recently are named with a system of consecutive numbers: EV-D68, EV-B69, EV-D70, EV-A71, etc., where genotyping ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poliomyelitis
Poliomyelitis, commonly shortened to polio, is an infectious disease caused by the poliovirus. Approximately 70% of cases are asymptomatic; mild symptoms which can occur include sore throat and fever; in a proportion of cases more severe symptoms develop such as headache, neck stiffness, and paresthesia. These symptoms usually pass within one or two weeks. A less common symptom is permanent paralysis, and possible death in extreme cases.. Years after recovery, post-polio syndrome may occur, with a slow development of muscle weakness similar to that which the person had during the initial infection. Polio occurs naturally only in humans. It is highly infectious, and is spread from person to person either through fecal-oral transmission (e.g. poor hygiene, or by ingestion of food or water contaminated by human feces), or via the oral-oral route. Those who are infected may spread the disease for up to six weeks even if no symptoms are present. The disease may be diagnosed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Picornavirus
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. Picornaviruses constitute the family ''Picornaviridae'', order ''Picornavirales'', and realm ''Riboviria''. There are 158 species in this family, assigned to 68 genera. Notable examples are genera '' Enterovirus'' (including '' Rhinovirus'' and ''Poliovirus''), ''Aphthovirus'', ''Cardiovirus'', and '' Hepatovirus''. Etymology The name "picornavirus" has a dual etymology. Firstly, the name derives from ''picorna''- which is an acronym for "''p''oliovirus, ''i''nsensitivity to ether, ''c''oxsackievirus, ''o''rphan virus, ''r''hinovirus, and ribo''n''ucleic ''a''cid". Secondly, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coxsackie A Virus
Coxsackie A virus (CAV) is a cytolytic Coxsackievirus of the ''Picornaviridae'' family, an enterovirus (a group containing the polioviruses, coxsackieviruses, and echoviruses). Viral structure and genome Coxsackie A virus is a subgroup of enterovirus A, which are small, non-enveloped, positive-sense, single-stranded RNA viruses. Its protective, icosahedral capsid has an external portion that contains sixty copies of viral proteins (VP1,-2,-3) and an internal portion surrounding the RNA genome containing sixty copies of VP4 viral proteins. This capsid mediates cell entry and elicits the humoral immune responses. Enteroviruses have a depression encircling each fivefold axis (canyon), which is their binding site for immunoglobulin-like receptors. This binding can trigger viral expansion and release of its genome. A complete genome analysis of Coxsackie virus A2, A4, A5, and A10 strains isolated from individuals with hand-foot-mouth disease showed that natural recombination is fre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enterovirus 71
Enterovirus 71 (EV71), also known as Enterovirus A71 (EV-A71), is a virus of the genus ''Enterovirus'' in the ''Picornaviridae'' family, notable for its role in causing epidemics of severe neurological disease and hand, foot, and mouth disease in children. It was first isolated and characterized from cases of neurological disease in California in 1969. Enterovirus 71 infrequently causes polio-like syndrome permanent paralysis. Evolution This virus is a member of the enterovirus species A. Species A was formerly assigned to the genus '' Rhinovirus''. This virus appears to have evolved only recently with the first known strain isolated in 1965. It was associated with an outbreak of neurological disease in the United States in 1969. It then spread to Europe with outbreaks there in Bulgaria (1975) and Hungary (1978). It has since spread to various countries in Asia where it has been responsible for several outbreaks, most recently in Cambodia (2012). The strains fall into six gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enterovirus 68
Enterovirus D68 (EV-D68) is a member of the ''Picornaviridae'' family, an enterovirus. First isolated in California in 1962 and once considered rare, it has been on a worldwide upswing in the 21st century. It is suspected of causing a polio-like disorder called acute flaccid myelitis (AFM). Virology EV-D68 is one of the more than one hundred types of enteroviruses, a group of ssRNA viruses containing the polioviruses, coxsackieviruses, and echoviruses. It is unenveloped. Unlike all other enteroviruses, EV-D68 displays acid lability and a lower optimum growth temperature, both characteristic features of the human rhinoviruses. It was previously called human rhinovirus 87 by some researchers. Since the year 2000, the original virus strains diversified and evolved a genetically distinct outbreak strain, clade B1. It is Clade B1, but not older strains, which has been associated with AFM and is neuropathic in animal models. Epidemiology Since its discovery in 1962, EV-D68 had ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coxsackie B Virus
Coxsackie B is a group of six serotypes of coxsackievirus (CVB1-CVB6), a pathogenic enterovirus, that trigger illness ranging from gastrointestinal distress to full-fledged pericarditis and myocarditis (coxsackievirus-induced cardiomyopathy). The genome of Coxsackie B virus consists of approximately 7,400 base pairs. Geographic distribution The various members of the Coxsackie B group were discovered almost entirely in the United States, appearing originally in Connecticut, Ohio, New York, and Kentucky, although a sixth member of the group has been found in the Philippines. However, all six serotypes have a global distribution and are a relatively common cause of gastrointestinal upset. The name reflects the first isolation from Coxsackie, New York. Transmission Infections are most commonly spread by the oral-fecal route, emphasizing the importance of good hygiene, especially hand-washing. Oral-oral and respiratory droplets can also be means of transmission. Epidemiology Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enterovirus A71
Enterovirus 71 (EV71), also known as Enterovirus A71 (EV-A71), is a virus of the genus ''Enterovirus'' in the ''Picornaviridae'' family, notable for its role in causing epidemics of severe neurological disease and hand, foot, and mouth disease in children. It was first isolated and characterized from cases of neurological disease in California in 1969. Enterovirus 71 infrequently causes polio-like syndrome permanent paralysis. Evolution This virus is a member of the enterovirus species A. Species A was formerly assigned to the genus '' Rhinovirus''. This virus appears to have evolved only recently with the first known strain isolated in 1965. It was associated with an outbreak of neurological disease in the United States in 1969. It then spread to Europe with outbreaks there in Bulgaria (1975) and Hungary (1978). It has since spread to various countries in Asia where it has been responsible for several outbreaks, most recently in Cambodia (2012). The strains fall into six gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conjunctivitis
Conjunctivitis, also known as pink eye, is inflammation of the outermost layer of the white part of the eye and the inner surface of the eyelid. It makes the eye appear pink or reddish. Pain, burning, scratchiness, or itchiness may occur. The affected eye may have increased tears or be "stuck shut" in the morning. Swelling of the white part of the eye may also occur. Itching is more common in cases due to allergies. Conjunctivitis can affect one or both eyes. The most common infectious causes are viral followed by bacterial. The viral infection may occur along with other symptoms of a common cold. Both viral and bacterial cases are easily spread between people. Allergies to pollen or animal hair are also a common cause. Diagnosis is often based on signs and symptoms. Occasionally, a sample of the discharge is sent for culture. Prevention is partly by handwashing. Treatment depends on the underlying cause. In the majority of viral cases, there is no specific treatment. Mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poliovirus
A poliovirus, the causative agent of polio (also known as poliomyelitis), is a serotype of the species '' Enterovirus C'', in the family of ''Picornaviridae''. There are three poliovirus serotypes: types 1, 2, and 3. Poliovirus is composed of an RNA genome and a protein capsid. The genome is a single-stranded positive-sense RNA (+ssRNA) genome that is about 7500 nucleotides long. The viral particle is about 30 nm in diameter with icosahedral symmetry. Because of its short genome and its simple composition—only RNA and a nonenveloped icosahedral protein coat that encapsulates it—poliovirus is widely regarded as the simplest significant virus. Poliovirus was first isolated in 1909 by Karl Landsteiner and Erwin Popper. The structure of the virus was first elucidated in 1958 using X-ray diffraction by a team at Birkbeck College led by Rosalind Franklin, showing the polio virus to have icosahedral symmetry. In 1981, the poliovirus genome was published by two different ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RNA Virus
An RNA virus is a virusother than a retrovirusthat 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. The International Committee on Taxonomy of Viruses (ICTV) classifies RNA viruses as those that belong to ''Group III'', ''Group IV'' or ''Group V'' of the Baltimore classification system. This category excludes ''Group VI'', viruses with RNA genetic material but which use DNA intermediates in their life cycle: these are called retroviruses, including HIV-1 and HIV-2 which cause AIDS. As of May 2020, all known RNA viruses encoding an RNA-directed RNA polymerase are believed to form a monophyletic group, known as the realm ''Riboviria''. The majority of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antibody
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the pathogen, called an antigen. Each tip of the "Y" of an antibody contains a paratope (analogous to a lock) that is specific for one particular epitope (analogous to a key) on an antigen, allowing these two structures to bind together with precision. Using this binding mechanism, an antibody can ''tag'' a microbe or an infected cell for attack by other parts of the immune system, or can neutralize it directly (for example, by blocking a part of a virus that is essential for its invasion). To allow the immune system to recognize millions of different antigens, the antigen-binding sites at both tips of the antibody come in an equally wide variety. In contrast, the remainder of the antibody is relatively constant. It only occurs in a few vari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RNA Viruses
''Orthornavirae'' is a kingdom of viruses that have genomes made of ribonucleic acid (RNA), those genomes encoding an RNA-dependent RNA polymerase (RdRp). The RdRp is used to transcribe the viral RNA genome into messenger RNA (mRNA) and to replicate the genome. Viruses in this kingdom also share a number of characteristics involving evolution, including high rates of genetic mutations, recombinations, and reassortments. Viruses in ''Orthornavirae'' belong to the realm '' Riboviria''. They are descended from a common ancestor that may have been a non-viral molecule that encoded a reverse transcriptase instead of an RdRp for replication. The kingdom is subdivided into five phyla that separate member viruses based on their genome type, host range, and genetic similarity. Viruses with three genome types are included: positive-strand RNA viruses, negative-strand RNA viruses, and double-stranded RNA viruses. Many of the most widely known viral diseases are caused by RNA vi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
