Origins of the Epidemic and Identification of the Novel Virus

The outbreak originated in the city of Wuhan, located within the province of Hubei inside mainland China in December of 2019. A cluster of cases of pneumonia of unknown etiology raised the alarm. By 7th of January, 2020, the virus was successfully isolated and its genome sequenced via deep sequencing analysis of samples from affected individuals’ respiratory tracts (Xu et al, 2020). This identified the virus as a previously unknown virus from the Coronaviridae family; a family which includes other known human-infecting viruses such as SARS-CoV and MERS-CoV; both coronaviruses which have caused outbreaks in 2002 and 2012 respectively. More specifically, SARSCoV-2 is a betacoronavirus like SARS-CoV and MERS-CoV; and the phylogenetically closestrelated, known betacoronavirus at 96% genetic similarity is BatCoV RaTG13, which is a SARS-like

virus restricted to bats (WHO-China Joint Mission, 2020)

Figure 1 –Phylogenetic analysis of SARS-CoV-2 (indicated as 2019-nCoV), showing relation to BAT-SL-CoV, SARS-CoV and MERSCoV (Source –WHO-China Joint Mission, 2020).