Dating first cases of COVID-19
PLOS Pathogens publishes Open Access research and commentary that significantly advance the understanding of pathogens and how they interact with host organisms.
Affiliation Durrell Institute of Conservation and Ecology, School of Anthropology & Conservation, Marlowe Building, University of Kent, Canterbury, Kent, United Kingdom
Affiliations School of Biosciences, University of Kent, Canterbury, Kent, United Kingdom, Research-Aid Networks, Chicago, Illinois, United States of America
Affiliations Biology Centre of the Czech Academy of Sciences, Institute of Hydrobiology, České Budějovice, Czech Republic, University of South Bohemia, Faculty of Science, Department of Ecosystem Biology, České Budějovice, Czech Republic
Questions persist as to the origin of the COVID-19 pandemic. Evidence is building that its origin as a zoonotic spillover occurred prior to the officially accepted timing of early December, 2019. Here we provide novel methods to date the origin of COVID-19 cases. We show that six countries had exceptionally early cases, unlikely to represent part of their main case series. The model suggests a likely timing of the first case of COVID-19 in China as November 17 (95% CI October 4). Origination dates are discussed for the first five countries outside China and each continent. Results infer that SARS-CoV-2 emerged in China in early October to mid-November, and by January, had spread globally. This suggests an earlier and more rapid timeline of spread. Our study provides new approaches for estimating dates of the arrival of infectious diseases based on small samples that can be applied to many epidemiological situations.
