Forecasting the Wuhan coronavirus (2019-nCoV) epidemics using a simple (simplistic) model

Abstract

Abstract and FindingsConfirmed infection cases in mainland China were analyzed using the data up to January 28, 2020 (first 13 days of reliable confirmed cases). In addition, all available data up to February 3 were processed the same way. For the first period the cumulative number of cases followed an exponential function. However, from January 28, we discerned a downward deviation from the exponential growth. This slower-than-exponential growth was also confirmed by a steady decline of the effective reproduction number. A backtrend analysis suggested the original basic reproduction number R0 to be about 2.4 – 2.5. We used a simple logistic growth model that fitted very well with all data reported until the time of writing. Using this model and the first set of data, we estimate that the maximum cases will be about 21,000 reaching this level in mid-February. Using all available data the maximum number of cases is somewhat higher at 29,000 but its dynamics does not change. These predictions do not account for any possible other secondary sources of infection.