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

As is the case with all epidemiological and mathematical modeling studies, this work has certain limitations, which include the quality of the available data, the specific assumptions that have been made regarding generation time estimates and assumptions related to under-reporting. However, we feel that our findings have demonstrated consistency even when confronted with alternative assumptions and scenarios. It is possible that generation times may differ depending on the type of farm (e.g. farrow-to-weaning vs. farrow-to-finisher). However, for our analysis, the two dominant herd types were finisher herds (61%) and farrow-to-finish herds (21%) suggesting that there was consistency in the type of herds throughout the time period considered which likely minimizes the potential impact of this variability. While it may in fact be the case that the publically reported data available online through the OMAFRA website may underrepresent the true number of PEDV positive farms in Ontario during this time period, the use of publically available data has a clear advantage of allowing for rapid and transparent analysis which would likely not be possible during times of emergency if obtaining data directly from the swine industry was the only way to conduct such analyses.