Figure 7

The fit of the Richards model to the entire incidence curve of the monkeypox epidemic in the USA for the week of 12 May 2022 through the week of 15 December 2022. The model provides a good fit to the entire incidence curve. The epidemic size parameter, K, was estimated at ~ 28,000–30,000 cases, similar to that estimated using the generalized logistic-growth model. The growth rate, \(r\), was estimated to be between 0.88 and 0.98, and the scaling parameter, \(a\), between 0.32 and 0.4. The growth scaling parameter, \(p\), is not estimated for the Richards model. The horizontal dashed lines in the top panels show the range of the 95% CIs of the parameter estimates. In the bottom panel, the solid red line is the median model fit, and the dashed lines correspond to the 95% PIs. The blue dots indicate the observed data points. The gray lines correspond to the mean of the model fits obtained from the parametric bootstrapping with 300 bootstrap realizations, and the cyan lines indicate the predictive uncertainty around the model fit.