الفهرس 
Aim of workOnly 14 pages are availabe for public view
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Abstract
The pandemic of 2019 novel coronavirus disease (COVID-19) started as an
outbreak of unexplained pneumonia in Wuhan, China for the first time in
December 2019. As of 12 June 2020, 7 410 510 confirmed cases and 418 294
deaths have been reported. The overall case fatality rate was reported to be 2.3%
according to a report from the Chinese center for disease control and prevention.
Coronaviruses are enveloped, positive single-stranded large RNA viruses
that infect humans, but also a wide range of animals. Coronaviruses were first
described in 1966 by Tyrell and Bynoe, who cultivated the viruses from patients
with common colds. Based on their morphology as spherical virions with a core
shell and surface projections resembling a solar corona, they were termed
coronaviruses (Latin: corona = crown). Four subfamilies, namely alpha-, beta-,
gamma- and delta coronaviruses exist. While alpha- and beta- coronaviruses
apparently originate from mammals, in particular from bats, gamma- and deltaviruses originate from pigs and birds. The genome size varies between 26 kb
and 32 kb. Among the seven subtypes of coronaviruses that can infect humans,
the beta-coronaviruses may cause severe disease and fatalities, whereas alphacoronaviruses cause asymptomatic or mildly symptomatic infections. Severe
Acute Respiratory Syndrome Coronavirus-2 (SARSCoV-2) belongs to the B
lineage of the beta-coronaviruses and is closely related to the SARS-CoV virus.
The clinical characteristics of COVID‐19 patients have been described in
several studies. COVID-19 is typically characterized by symptoms of viral
pneumonia such as fever, fatigue, dry cough, anosmia and headache, which may
evolve to respiratory failure, the pathogen has now been named (SARS-CoV-2).
Digestive system involvement such as nausea, vomiting and diarrhea has also
been reported. Although, diffuse alveolar damage and acute respiratory failure
are the main features of COVID‐19, the impairment of other organs are
demonstrated.