1. Transmission Decay
Taken from Statistical Inference in a Stochastic Epidemic SEIR Model with Control Intervention: Ebola as a Case Study, by Phenyo E. Lekone, et. al.
“In order to account for the control intervention we assume that the transmission parameter is constant up to the time point when the control measures are introduced and after that decays exponentially. This can be formulated as
where t* is the time point at which control measures are introduced, is the initial transmission rate, and q>0 is the rate at which decays for t>t*.”