where P[R] is taken as the posterior in [13] at time t, and P[DT(t+t)rDT(t)|R] is the statistical epidemic model. Failure to predict future observed cases at time t+t, can then be formulated as a p-value significance test at any chosen level of credibility. A statistical anomaly, i.e., future cases falling outside the credible interval defined by previous observations, may signal changes in epidemiological parameters, specifically in transmissibility (either by pathogen evolution or host population changes) as measured by R. We provide an example in Figure 5 , for simulated data with R 0 = 0.8 changing to R 0 = 1.3, where we show the predicted 95% credible interval for new cases vs. the number of cases actually observed (see also Figure S7 in Supplementary Material S1).