Coronavirus disease 2019 ( COVID-19 ) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). [9] It was first identified in December 2019 in Wuhan , China, and has since spread globally, resulting in an ongoing pandemic . [10] [11] As of 9 May 2020, more than 3.93 million cases have been reported across 187 countries and territories, resulting in more than 274,000 deaths . More than 1.31 million people have recovered. [8] Common symptoms include fever , cough , fatigue , shortness of breath , and loss of smell and taste. [5] [12] [13] While the majority of cases result in mild symptoms, some progress to acute respiratory distress syndrome (ARDS), multi-organ failure , septic shock , and blood clots . [14] [15] [16] The time from exposure to onset of symptoms is typically arou...