The 2019 novel coronavirus (2019-nCoV) outbreak has sparked a speedy response, with scientists, physicians, and front-line healthcare professionals analyzing data in real-time in order to share findings and call out misinformation. Today, The Lancet published two new peer-reviewed studies: one which found that the new coronavirus is genetically distinct from human SARS and MERS, related viruses which caused their own outbreaks, and a second which reports clinical observations of 99 individuals with 2019-nCoV.

The first cases of the coronavirus outbreak were reported in late December 2019. In this new study, Nanshan Chen and colleagues analyzed available clinical, demographic, and laboratory data for 99 confirmed coronavirus cases at the Wuhan Jinyintan Hospital between Jan 1 to Jan 20, 2020, with clinical outcomes followed until 25th January.

Chen and colleagues reported that the average age of the 99 individuals with 2019-nCoV is around 55.5 years, where 51 have additional chronic conditions, including cardiovascular and cerebrovascular (blood flow to the brain) diseases. Clinical features of the 2019-nCoV include a fever, cough, shortness of breath, headaches, and a sore throat. 17 individuals went on to develop acute respiratory distress syndrome, resulting in death by multiple organ failure in 11 individuals. However, it is important to note here that most of the 2019-nCoV cases were treated with antivirals (75 individuals), antibiotics (70) and oxygen therapy (75), with promising prognoses, where 31 individuals were discharged as of 25th January.

Based on this sample, the study suggests that the 2019 coronavirus is more likely to affect older men already living with chronic conditions but as this study only includes 99 individuals with confirmed cases, it may not present a complete picture of the outbreak. As of right now, there are over 6,000 confirmed coronavirus cases reported, where a total of 126 individuals have recovered, and 133 have died.

In a second Lancet study, Roujian Lu and their fellow colleagues carried out DNA sequencing on samples, obtained from either a throat swab or bronchoalveolar lavage fluids, from eight individuals who had visited the Huanan seafood market in Wuhan, China, and one individual who stayed in a hotel near the market. Upon sequencing the coronaviruss genome, the researchers carried out phylogenetic analysis to narrow down the viruss likely evolutionary origin, and homology modelling to explore the virus receptor-binding properties.

Lu and their fellow colleagues found that the 2019-nCoV genome sequences obtained from the nine patients were very similar (>99.98% similarity). Upon comparing the genome to other coronaviruses (like SARS), the researchers found that the 2019-nCoV is more closely related (~87% similarity) to two bat-derived SARS-like coronaviruses, but does not have as high genetic similarity to known human-infecting coronaviruses, including the SARS-CoV (~79%) orMiddle Eastern Respiratory Syndrome (MERS) CoV (~50%).

The study also found that the 2019-nCoV has a similar receptor-binding structure like that of SARS-CoV, though there are small differences in certain areas. This suggests that like the SARS-CoV, the 2019-nCoV may use the same receptor (called ACE2) to enter cells, though confirmation is still needed.

Finally, phylogenetic analysis found that the 2019-nCoV belongs to the Betacoronavirus family the same category that bat-derived coronaviruses fall into suggesting that bats may indeed be the 2019-nCoV reservoir. However, the researchers note that most bat species are hibernating in late December, and that no bats were being sold at the Huanan seafood market, suggesting that while bats may be the initial host, there may have been a secondary animal species which transmitted the 2019-nCoV between bats and humans.

Its clear that we can expect new findings from the research community in the coming days as scientists attempt to narrow down the source of the 2019-nCoV.

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