Figure 9

The generalized logistic-growth model (GLM) fit, and 4-week ahead forecast based on the first 12 weeks of the monkeypox epidemic in the USA for the week of 12 May 2022 through the week of 28 July 2022. The model fit is consistent with early sub-exponential growth dynamics (i.e., p ~ 0.92), with a growth rate (\(r)\) estimated between 0.89 and 1.4. The epidemic size parameter, K, was estimated to be between 20,000 and 29,000 cases, and the scaling parameter, \(a\), is not estimated when employing a GLM. 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% prediction intervals. 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. The vertical dashed line separates the 12-week calibration (left) and the 4-week ahead forecasting period (right). Overall, the 4-week ahead forecast using the GLM with a 12-week calibration period tracked the trajectory of the epidemic well.