Understanding the early dynamics of the 2014 porcine epidemic diarrhea virus (PEDV) outbreak in Ontario using the incidence decay and exponential adjustment (IDEA) model

Greer, Amy L.; Spence, Kelsey; Gardner, Emma

Control parameter values greater than zero indicate that effective control measures were occurring within the province to help slow epidemic growth during the course of the outbreak. In a descriptive sense, an increasing control parameter indicates that the epidemic growth dynamic is slowing [20] [21] [22] . There are a variety of possible mechanistic explanations for slowing epidemic growth within the context of the PEDV outbreak including decreased rate of contact between farms (e.g. decreased truck movements), greater farmlevel biosecurity, depletion of susceptible farms/premises within the province, environmental conditions which are less favorable for the persistence of the pathogen on vectors of transmission such as trucks and equipment, or any other factor which could act to reduce the force of infection. Despite this limitation, the model does permit the user to identify acceleration or deceleration of the epidemic dynamic based on the available data, including early in the course of an outbreak.