COVID-19 (Coronavirus Disease 2019; COVID) By Brenda L Tesini, MD, University of Rochester School of Medicine and Dentistry Reviewed / Revised Aug 2022 | Modified Sep 2022 View Patient Education Transmission Symptoms and Signs Diagnosis Treatment Post-COVID-19 Infection Prevention More Information Topic Resources SARS-CoV-2 COVID-19 is an acute, sometimes severe, respiratory illness caused by the novel coronavirus SARS-CoV-2.