write an article on covid-19 in 1000 Words...
Answers
COVID-19
COVID-19 (coronavirus disease 2019) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), previously known as the 2019 novel coronavirus (2019-nCoV), a strain of coronavirus. The first cases were seen in Wuhan, China, in late December 2019 before spreading globally. The current outbreak was officially recognised as a pandemic by the World Health Organisation (WHO) on 11 March 2020.
Definitive diagnosis of COVID-19 requires a positive RT-PCR test. Current best practice advises that CT chest is not used to diagnose COVID-19, but maybe helpful in assessing for complications. The non-specific imaging findings are most commonly of atypical or organising pneumonia, often with a bilateral, peripheral, and basal predominant distribution. No effective treatment or vaccine exists currently.
The World Health Organisation originally called this illness "novel coronavirus-infected pneumonia (NCIP)", and the virus itself had been provisionally named "2019 novel coronavirus (2019-nCoV)"
On 11 February 2020, the WHO officially renamed the clinical condition COVID-19 (a shortening of COronaVIrus Disease-19) 15. Coincidentally, on the same day, the Coronavirus Study Group of the International Committee on Taxonomy of Viruses renamed the virus "severe acute respiratory syndrome coronavirus 2" (SARS-CoV-2) 16,22,46. The names of both the disease and the virus should be fully capitalised, except for the 'o' in the viral name, which is in lowercase 16,22,41.
The official virus name is similar to SARS-CoV, the virus strain that caused epidemic severe acute respiratory syndrome (SARS) in 2002-2004, potentially causing confusion 38. The WHO has stated it will use "COVID-19 virus" or the "virus that causes COVID-19" instead of its official name, SARS-CoV-2 when communicating with the public 45.
As of early June 2020, the number of cases of confirmed COVID-19 globally is over 6 million affecting virtually every territory, other than isolated South Pacific island states and Antarctica, according to an online virus tracker created by the medical journal, The Lancet, and hosted by Johns Hopkins University 5. As of June 2020, the United States had more than 1.5 million cases, with more than ten other countries with >100,000 cases 5.
NB: Surveillance methods and capacity vary dramatically between countries. Presymptomatic carriers may be present in many communities and presymptomatic transmission has been documented; asymptomatic carriers have been uncommonly reported and no asymptomatic transmission has been documented (May 2020) 113.
The R0 (basic reproduction number) of SARS-CoV-2 has been estimated between 2.2 and 3.28 in a non-lockdown population, that is each infected individual, on average, causes between 2-3 new infections 12,33.
The incubation period for COVID-19 was initially calculated to be about five days, which was based on 10 patients only 12. An American group performed an epidemiological analysis of 181 cases, for which days of exposure and symptom onset could be estimated accurately. They calculated a median incubation period of 5.1 days, that 97.5% became symptomatic within 11.5 days (CI 8.2 to 15.6 days) of being infected, and that extending the cohort to the 99th percentile results in almost all cases developing symptoms in 14 days after exposure.