Severe Acute Respiratory Syndrome Coronavirus 2

Marks, Michael; O’Hara, Geraldine; Houlihan, Catherine; Bell, Lucy; Heightman, Melissa; Hart, Nicholas

COVID-19, caused by SARS-CoV-2, is an emerging viral respiratory pathogen. The disease was first described in China in 2019, likely emerging as a zoonosis, before spreading worldwide to cause a severe global pandemic in 2020. COVID-19 is transmitted person to person, predominantly by droplet spread. COVID-19 causes a wide spectrum of clinical illness ranging from asymptomatic infection, to a mild self-limiting illness. A small proportion of individuals will go on to develop a more severe respiratory illness which may be complicated by acute respiratory distress syndrome. The majority of individuals will make a full recovery but a minority of patients will have a more severe outcome. Age is the strongest predictor of outcomes with mortality increasing to 15% or higher among those aged 80 years or older. Treatment options for COVID-19 continue to evolve. The strongest current evidence is the use of systemic corticosteroids which reduce mortality in patients with moderate to severe COVID-19. Given the epidemic nature of COVID-19 early surge planning and expansion of both staff and bed base capacity are critical. At the time of writing a number of promising COVID-19 vaccines have been developed but the long term impact of these vaccines on the pandemic is uncertain.