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 .
【저자키워드】 COVID-19, Reproduction number, 【초록키워드】 coronavirus disease, progression, Italy, China, Epidemic, Germany, Spain, France, basic reproduction number, estimate, distribution, New York, Switzerland, doubling, discrepancy, SEIR, state, initial, proportion, explained, faster, super-spreaders, 【제목키워드】 exponential growth phase, event, initiated,