Emergence of SARS-CoV-2 and its outlook.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported at the end of 2019 in China. By the end of February 2020, the virus has spread worldwide through continuous human-to-human transmission via contact and droplet infection, demonstrating the ease with which emerging viruses disperse globally through the mass transport system. Here, we summarize our knowledge of other coronaviruses that have infected humans in comparison with SARS-CoV-2. 2020, National Center for Global Health and Medicine.