Outbreak investigation of porcine epidemic diarrhea in swine in Ontario.

In January of 2014, porcine epidemic diarrhea virus (PEDV) was diagnosed in a swine herd in southwestern Ontario (1,2). Porcine epidemic diarrhea had not been previously diagnosed in Canada but was reported in the United States in May of 2013. Following the initial discovery, another 62 cases of PEDV were diagnosed between January 22, 2014 and July 21, 2014. An outbreak investigation was conducted by veterinarians at the Ontario Ministry of Agriculture, Food and Rural Affairs to describe the outbreak of PEDV in Ontario and to generate hypotheses regarding the origin and spread of the outbreak. The investigation was conducted between January 23 and July 21, 2014, and consisted of 3 components: an outbreak investigation survey of cases with an in-depth investigation into the first 6 cases; environmental surveillance from transport trailers, processing plants, and an assembly yard; and feed testing based on results of the survey of the initial cases. A case was defined as a farm in Ontario diagnosed with PEDV by reverse transcriptase-polymerase chain reaction (RT-PCR) on samples originating from animals. Porcine delta coronavirus was also diagnosed concurrently with the outbreak of PEDV; however, this report is limited to cases of PEDV.