Coronavirus Disease 2019 ( COVID - 19 ) was declared as pandemic bythe World Health Organization on March 11th, 2020 mainly due to thespeed and scale of the transmission of the disease [1]. Before that, it
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started as an epidemic in mainland China with the focus being firstly
reported in the city of Wuhan, Hubei province in February 26th [2–4].
The etiologic agent of COVID - 19 was isolated and identified as a novel
coronavirus, initially designated as 2019 - nCoV [5]. Later, the virus
genome was sequenced [6] and because it was genetically related to the
coronavirus outbreak responsible for the SARS outbreak of 2003, the
virus was named as severe acute respiratory syndrome coronavirus - 2
( SARS - CoV - 2 ) by the International Committee for Taxonomy of Viruses
[7, 8].
The origin and source of the SARS - CoV - 2 remains unknown, although the initial cases have been associated with the Huanan South
China Seafood Market where snakes, birds and other animals such as
bats were sold. Considering that many of the early patients worked in or
visited the market in contrast to the exported cases, it was suggested
either a human to human transmission or a more widespread animal
source [9]. A suspected bat origin was suggested after 96 % genome
sequence identity was demonstrated between SARS - CoV - 2 and another
coronavirus named Bat - CoV - RaTG13 isolated from bat species which
colonized a province nearly 2000 km away from Wuhan [6, 10]. Pangolins were also suggested as natural host of coronaviruses [11, 12].
However, evidence of human to human transmission became strongly
supported on January 22nd, 2020 after a visit conducted by a WHO
delegation to the city of Wuhan [13]. Since the first outbreak recognized in February 2020, the disease spread rapidly around the
world. According to the European Centre for Disease Prevention and
Control, as of 17th of June 2020; 8, 142, 129 cases of COVID - 19 and
443, 488 deaths have been reported worldwide since 31st December
2019. American continent was among the ones with highest number of
cases ( 3, 987, 543 ) with United States and Brazil the leading countries
( 2, 137, 731 and 923, 189 respectively ) .
