Published time: 23 March 2020
Authors: Joseph A Lewnard, Nathan C Lo
On Dec 31, 2019, the WHO China Country Office received notice of a cluster of pneumonia cases of unknown aetiology in the Chinese city of Wuhan, Hubei province. The incidence of coronavirus disease 2019 (COVID-19; caused by severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) has since risen exponentially, now affecting all WHO regions. The number of cases reported to date is likely to represent an underestimation of the true burden as a result of shortcomings in surveillance and diagnostic capacity affecting case ascertainment in both high-resource and low-resource settings. By all scientifically meaningful criteria, the world is undergoing a COVID-19 pandemic.
Scientific and ethical basis for social-distancing interventions against COVID-19