Sars-cov-2 or SARS-CoV-2 (Severe acute respiratory syndrome coronavirus 2, which roughly means "severe acute respiratory syndrome coronavirus 2") is a human, and various animal species, infectious coronavirus that causes covid-19 disease and which gave rise to the coronavirus pandemic 2019–2021. The virus, which was first discovered in late 2019 in Wuhan, China, has previously been called the 2019 novel coronavirus (2019-nCoV) and informally also the Wuhan coronavirus. Sars-cov-2 causes respiratory infections that in most cases lead to milder disease symptoms that go away within two weeks. Sometimes, especially in the elderly, people with chronic illness and certain other risk factors, a viral infection can be fatal. The origin, that is, from which host animal the virus originates, is still unknown.
On 11 February 2020, the International Committee on Taxonomy of Viruses (ICTV) gave the virus the official name "severe acute respiratory syndrome coronavirus 2", sars-cov-2, based on guidelines for naming new diseases published in 2015 by the World Health Organization (WHO). On the same day, the disease that causes viruses was assigned by the WHO the official name "covid-19", from the English words "coronavirus", "disease" and the year 2019 when the virus outbreak began. Previously, the virus was called the 2019 novel coronavirus (2019-nCoV), a temporary name given by the WHO. Informally, the virus has also been called the Wuhan coronavirus or the new coronavirus.
The virus sars-cov-2 causes covid-19 disease. The disease causes symptoms such as fever, cough and fatigue. The incubation period is usually about 5 days but can range from two to 14 days. In Sweden, the disease covid-19 is classified as a socially dangerous disease.
Discovery and the outbreak 2019–2020
The virus was discovered at the end of 2019. On December 31, 2019, the World Health Organization's (WHO) local office in China received information that a new type of pneumonia had appeared in the city of Wuhan. On January 7, 2020, Chinese authorities were able to identify the virus as a new type of coronavirus. In early 2020, the virus caused an epidemic in China, with data on more than 80,000 diseases and more than 3,000 deaths. The dark figure is assumed to be large. The epidemic started in the province of Hubei in China, but then spread to other Chinese provinces and other countries. On 11 March 2020, the World Health Organization (WHO) announced that the spread of the coronavirus was classified as a pandemic. As of 5 November 2020, a total of over 49 million cases had been registered and over 1,238,000 people had died.
Systematics and origin
Sars-cov-2 is a coronavirus belonging to the group SARS virus (SARS-CoV or SARSr-COV) which has previously become widely known for the virus strain SARS-CoV which caused the outbreak of the disease sars. The species is part of the genus Betacoronavirus and the subgenus Sarbecovirus. The coronavirus family occurs in a number of animals that act as natural reservoirs for them. In rare cases, they can be transmitted to humans. For example, directly from an infected animal, or via another animal, a so-called intermediate host, which acts as a carrier of the virus but which itself is not infected. Sometimes a virus can mutate and thus become contagious to humans. Genetically, SARS-CoV-2 variants of coronavirus found in batsOf other known coronaviruses that have infected humans, SARS-CoV-2 is mainly similar to SARS-CoV, the virus that causes the disease sars. SARS-CoV has been found in several mammals and, like sars-cov-2, has great genetic similarities to those found in coronaviruses in bats. Although several similar virus strains are found in bats, they are not a likely direct source of human spread. This is due to the fact that bats in the area around Wuhan during the outbreak are hibernating and that the previous outbreaks of the closely related and similar viruses SARS-CoV and ME