Detecting Differential Transmissibilities That Affect the Size of Self-Limited Outbreaks
A) The results of estimating the effective reproduction number, , for six inter-related models of transmission are shown. The contours show the 95% confidence regions for three models that allow different values of for cases occurring before versus after June 1, 2013. The distinction is that each model makes different assumptions about the degree of transmission heterogeneity (as explained in the text). The black dot shows the maximum likelihood estimation (MLE) estimate of the values for these three models. The dashed grey line indicates when does not change with time. The dashed colored lines show the MLE estimate and 95% confidence interval of for the three models that assume transmissibility of cases is independent of time. The slight displacement of the colored lines from the dashed grey line is only for visual clarity. B) The fit of our preferred model to the early MERS-CoV chain size data is shown (Table 1). The error bars of the data correspond to 95% confidence intervals as determined by non-parametric bootstrapping of chain sizes. C) The fit of our preferred model to the late MERS-CoV chain size data is shown.