Coronavirus

Coronavirus

Coronaviruses are a group of related RNA viruses that cause diseases in mammals and birds. In humans and birds, they cause respiratory tract infections that can range from mild to lethal. Mild illnesses in humans include some cases of the common cold, while more lethal varieties can cause SARS, MERS, and COVID-19. They are enveloped viruses with a positive-sense single-stranded RNA genome and a nucleocapsid of helical symmetry. They have characteristic club-shaped spikes that project from their surface, which in electron micrographs create an image reminiscent of the solar corona.

About Coronavirus in brief

Summary CoronavirusCoronaviruses are a group of related RNA viruses that cause diseases in mammals and birds. In humans and birds, they cause respiratory tract infections that can range from mild to lethal. Mild illnesses in humans include some cases of the common cold, while more lethal varieties can cause SARS, MERS, and COVID-19. In cows and pigs they cause diarrhea, while in mice they cause hepatitis and encephalomyelitis. They are enveloped viruses with a positive-sense single-stranded RNA genome and a nucleocapsid of helical symmetry. They have characteristic club-shaped spikes that project from their surface, which in electron micrographs create an image reminiscent of the solar corona, from which their name derives. As of 2020, 45 species are officially recognised. The scientific name Coronavirus was accepted as a genus name by the International Committee for the Nomenclature of Viruses in 1971. The common name coronavirus is used to refer to any member of the subfamily Orthocoronaviralinae. The name is derived from Latin corona meaning ‘crown’ or ‘wreath’, itself a borrowing from Greek korṓnē, ‘garland, wreath’ The name refers to the characteristic appearance of virions by electron microscopy, which have a fringe of large, bulbous surface projections. This morphology is created by the viral spike peplomers, which are proteins on the surface of the virus.

The virus could not be cultivated using standard techniques which had successfully cultivated rhinoviruses and other known common cold viruses. The new cultivating method was introduced to the lab by Bertil Hoorn and Dorothy Hamre. The novel virus caused a cold and inactivated by ether which indicated it had a lipid envelope. In 1965, Tyrrell and Bynoe successfully cultivated the novel virus by serially passing it through organ culture of human trachea. It was isolated by intranasally inoculated into volunteers when intransferable by ether. In 1967, B814 and 229E were shown to be related by the general microscopy to be able to be distinguished by their general shape and morphologically similar to each other. In the late 1940s, JHM that causes brain disease and mouse hepatitis virus that causes hepatitis in mice were discovered. As the number of new species increased, the genus was split into four genera, namely Alphacor onavirus, Betacoron avirus, DeltacorOnavirus and Gammacorons. In 2009, the species of coronav virus was officially recognised as Alphaconav virus. It is the only virus in the world that causes the brain disease JHM. The species is also the only one that can cause the liver and kidney diseases JHM and adenovirus. It has been identified as the cause of SARS and MERS in humans.