Author(s)

Qingyi Cai

Corresponding Author

Qingyi Cai

ABSTRACT

Since December 31, 2019, Coronavirus disease 2019 (COVID-19) has spread to 221 countries and territories to date. It has caused several millions of deaths with several hundred millions of confirmed cases worldwide, posing a serious threat to global public health. COVID-19 is caused by a novel coronavirus, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 virus is not the first virus belonging to the B lineage of betacoronavirus. Two recent outbreaks of human coronavirus caused by betacoronavirus are severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). In 2002, SARS first occurred in China and spread quickly, resulting in hundreds of deaths; in 2012, MERS first emerged in Saudi Arabia and spread to several countries linked through the Arabian Peninsula. Therefore, it is worthwhile to find the similarities and differences among these three human coronaviruses to examine the reality that COVID-19 has become the only one among three to be labeled as “pandemic”. Hence, this review will capture possible reasons behind the high spread of COVID-19 by comparing the known characteristics of SARS and MERS, including cause, transmission, and risk factors.

KEYWORDS

SARS-CoV, MERS-CoV, SARS-CoV-2, epidemiology, pandemic, cause, transmission, risk factors