This excerpt is from Wikipedia, Visit the full article here.
It's important to follow through and read the links and citation notes Wikipedia furnishes at the bottom of all its articles. At the bottom of this article you will find additional resources you can read to further your understanding of the Coronavirus strain that has affected every continent except one - the Antarctic.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2),[2][3] colloquially known as the coronavirus and previously known by the provisional name 2019 novel coronavirus (2019-nCoV),[4][5][6] is a positive-sense single-stranded RNA virus.[7] It causes coronavirus disease 2019 (COVID-19), a respiratory illness. SARS-CoV-2 is contagious in humans, and the World Health Organization (WHO) has designated the ongoing pandemic of COVID-19 a Public Health Emergency of International Concern.[8][9][10] The strain was first discovered in Wuhan, China, so it is sometimes referred to as the "Wuhan virus"[11][12] or "Wuhan coronavirus".[13][14][15] Because the WHO discourages the use of names based upon locations[16][17] and to avoid confusion with the disease SARS,[18] it sometimes refers to SARS-CoV-2 as "the COVID-19 virus" in public health communications.[19] The general public frequently calls both SARS-CoV-2 and the disease it causes "coronavirus", but scientists typically use more precise terminology.[20]
Taxonomically, SARS-CoV-2 is a strain of Severe acute respiratory syndrome-related coronavirus (SARSr-CoV).[2] It is believed to have zoonotic origins and has close genetic similarity to bat coronaviruses, suggesting it emerged from a bat-borne virus.[21][22][23] An intermediate animal reservoir such as a pangolin is also thought to be involved in its introduction to humans.[16][24] The virus shows little genetic diversity, indicating that the spillover event introducing SARS-CoV-2 to humans is likely to have occurred in late 2019.[25]
Epidemiological studies estimate each infection results in 1.4 to 3.9 new ones when no members of the community are immune and no preventive measures taken. The virus is primarily spread between people through close contact and via respiratory droplets produced from coughs or sneezes.[26][27] It mainly enters human cells by binding to the receptor angiotensin converting enzyme 2 (ACE2).[28]
Virology
Infection
Human-to-human transmission of SARS-CoV-2 has been confirmed during the 2019–20 coronavirus pandemic.[10] Transmission occurs primarily via respiratory droplets from coughs and sneezes within a range of about 1.8 metres (6 ft).[27][29] Indirect contact via contaminated surfaces is another possible cause of infection.[30] Preliminary research indicates that the virus may remain viable on plastic and steel for up to three days, but does not survive on cardboard for more than one day or on copper for more than four hours;[31] the virus is inactivated by soap, which destabilises its lipid bilayer.[32][33] Viral RNA has also been found in stool samples from infected people.[34]
The degree to which the virus is infectious during the incubation period is uncertain, but research has indicated that the pharynx reaches peak viral load approximately four days after infection.[35][36] On 1 February 2020, the World Health Organization (WHO) indicated that "transmission from asymptomatic cases is likely not a major driver of transmission".[37] However, an epidemiological model of the beginning of the outbreak in China suggested that "pre-symptomatic shedding may be typical among documented infections" and that subclinical infections may have been the source of a majority of infections.[38]
No comments:
Post a Comment