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

Data used for the fitting of the IDEA model included only a subset of all laboratory confirmed PEDV positive farms in Ontario. Specifically, we used cumulative incidence data from February 20, 2014 to April 30, 2014. Twenty cases of PEDV occurred prior to this time period (between January 22, 2014 and February 19, 2014), however these cases have been excluded from our analyses, as it is believed that these initial cases in Ontario were linked to a point source exposure related to PEDV contaminated swine feed [15] . The contaminated feed was identified on February 9, 2014 and subsequently recalled by the manufacturer. As a result, we have excluded all cases prior to February 20 th , 2014 since direct farm-to-farm transmission is not thought to have been the primary mechanism of transmission for this early time period. In addition, we have excluded five cases that were identified after April 30, 2014 because the time between these cases exceeded the possible generation times suggesting that these were sporadic cases and therefore, cases occurring after April 30, 2014 were also excluded from the analyses.