8/13/2023 0 Comments Meta bat 2020![]() ![]() ![]() Laser light scattering experiments suggest that speaking is an additional mode of transmission and a far-reaching one, indoors, with little air flow. Transmission was initially assumed to occur primarily via respiratory droplets from coughs and sneezes within a range of about 1.8 metres (6 ft). Human-to-human transmission of SARS‑CoV‑2 was confirmed on 20 January 2020 during the COVID-19 pandemic. ( Learn how and when to remove this template message) Referring to COVID-19 as the "Wuhan virus" has been described as dangerous by WHO officials, and as xenophobic by University of California at Berkeley Asian American studies lecturer Harvey Dong. To avoid confusion with the disease SARS, the WHO sometimes refers to SARS‑CoV‑2 as "the COVID-19 virus" in public health communications and the name HCoV-19 was included in some research articles. On 11 February 2020, the International Committee on Taxonomy of Viruses adopted the official name "severe acute respiratory syndrome coronavirus 2" (SARS‑CoV‑2). This was in accordance with WHO's 2015 guidance against using geographical locations, animal species, or groups of people in disease and virus names. ![]() In January 2020, the World Health Organization (WHO) recommended "2019 novel coronavirus" (2019-nCoV) as the provisional name for the virus. Terminologyĭuring the initial outbreak in Wuhan, China, various names were used for the virus some names used by different sources included "the coronavirus" or "Wuhan coronavirus". It enters human cells by binding to angiotensin-converting enzyme 2 (ACE2), a membrane protein that regulates the renin–angiotensin system. The virus is airborne and primarily spreads between people through close contact and via aerosols and respiratory droplets that are exhaled when talking, breathing, or otherwise exhaling, as well as those produced from coughs and sneezes. However, some subsequent variants have become more infectious. Įpidemiological studies estimate that, in the December 2019–September 2020 period, each infection resulted in an average of 2.4–3.4 new infections when no members of the community are immune and no preventive measures are taken. 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. Research is ongoing as to whether SARS‑CoV‑2 came directly from bats or indirectly through any intermediate hosts. Available evidence indicates that it is most likely of zoonotic origin and has close genetic similarity to bat coronaviruses, suggesting it emerged from a bat-borne virus. Despite its close relation to SARS-CoV-1, its closest known relatives, with which it forms a sister group, are the derived SARS viruses BANAL-52 and RaTG13. SARS‑CoV‑2 is a virus of the species severe acute respiratory syndrome–related coronavirus (SARSr-CoV), related to the SARS-CoV-1 virus that caused the 2002–2004 SARS outbreak. SARS‑CoV‑2 is a positive-sense single-stranded RNA virus that is contagious in humans. ![]() First identified in the city of Wuhan, Hubei, China, the World Health Organization declared the outbreak a public health emergency of international concern from January 30, 2020, to May 5, 2023. The virus previously had a provisional name, 2019 novel coronavirus ( 2019-nCoV), and has also been called the human coronavirus 2019 ( HCoV-19 or hCoV-19). Severe acute respiratory syndrome coronavirus 2 ( SARS‑CoV‑2) is a strain of coronavirus that causes COVID-19 (coronavirus disease 2019), the respiratory illness responsible for the COVID-19 pandemic. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |