Super-spreading events initiated the exponential growth phase of COVID-19 with ℛ0 higher than initially estimated

Marek Kochańczyk; Frederic Grabowski; Tomasz Lipniacki

doi:10.1098/rsos.200786

Super-spreading events initiated the exponential growth phase of COVID-19 with ℛ₀ higher than initially estimated

R Soc Open Sci. 2020 Sep 23;7(9):200786. doi: 10.1098/rsos.200786. eCollection 2020 Sep.

Authors

Marek Kochańczyk¹, Frederic Grabowski², Tomasz Lipniacki¹

Affiliations

¹ Department of Biosystems and Soft Matter, Institute of Fundamental Technological Research, Polish Academy of Sciences, 02-106 Warsaw, Poland.
² Faculty of Mathematics, Informatics and Mechanics, University of Warsaw, 02-097 Warsaw, Poland.

Abstract

The basic reproduction number $R_{0}$ of the coronavirus disease 2019 has been estimated to range between 2 and 4. Here, we used an SEIR model that properly accounts for the distribution of the latent period and, based on empirical estimates of the doubling time in the near-exponential phases of epidemic progression in China, Italy, Spain, France, UK, Germany, Switzerland and New York State, we estimated that $R_{0}$ lies in the range 4.7-11.4. We explained this discrepancy by performing stochastic simulations of model dynamics in a population with a small proportion of super-spreaders. The simulations revealed two-phase dynamics, in which an initial phase of relatively slow epidemic progression diverts to a faster phase upon appearance of infectious super-spreaders. Early estimates obtained for this initial phase may suggest lower $R_{0}$ .

Keywords: COVID-19; reproduction number.

Associated data

figshare/10.6084/m9.figshare.c.5120378