Advances in the etiology of COVID-19

In December 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the outbreak of COVID-19 in Wuhan. It is a kind of enveloped positive-strand RNA viruses, belonging to the subgenus Sarbecovirus of the genus Betacoronavirus. It is similar to other viruses of the subgenus Sarbecovirus in genomic structure and closely related to the bat coronavirus (RaTG13), indicating that its natural host is likely to be bat, but the intermediate host is still controversial. SARS-CoV-2 infects host cells with angiotensin-converting enzyme 2 (ACE2) as a receptor. At present, SARS-CoV-2 has undergone some mutations. This article reviewed the current research situation and progress in the etiology of COVID-19. Key words: COVID-19; Severe acute respiratory syndrome coronavirus 2; Etiology