Correcting the actual reproduction number: A simple method to estimate R0 from early epidemic growth data

Abstract

The basic reproduction number, R0, a summary measure of the transmission potential of an infectious disease, is estimated from early epidemic growth rate, but a likelihood-based method for the estimation has yet to be developed. The present study corrects the concept of the actual reproduction number, offering a simple framework for estimating R0 without assuming exponential growth of cases. The proposed method is applied to the HIV epidemic in European countries, yielding R0 values ranging from 3.60 to 3.74, consistent with those based on the Euler-Lotka equation. The method also permits calculating the expected value of R0 using a spreadsheet. © 2010 by the authors; licensee Molecular Diversity Preservation International.