, where y t is the observed daily number of notified cases at time t and z t is the daily number of notified cases as predicted by the model at time t (times t represent days before the intervention). Model M outputs the daily incidence of symptomatic cases,Ĩ I s h (t), and asymptomatic cases, I I a h (t). Notified cases z t at time t were estimated by sampling from a binomial distribution of size n~Ĩ I s h (t) and probability p~p n , where p n is the notification ratio (p n~0 :54 [18] ).