A Manitoba research study has shown the virus responsible for Porcine Epidemic Diarrhea can survive for long periods of time but the infectivity of the virus will vary according its depth in the lagoon and environmental conditions.
The University of Manitoba and the Prairie Agricultural Machinery Institute analyzed samples collected at various depths of the earthen manure storage of a PED infected farm over 9 months and over 6 months on another farm.
Dr. Ehsan Khafipour, an assistant professor with the University of Manitoba, told those on hand yesterday for the 2016 Manitoba Swine Seminar, the intent was to find out how long the virus could survive in the stored manure and assess its infectivity.
Even after 9 months after the initial outbreak of the PEDv in the farm, still the virus is present in the infected manure. Up to 88 percent of our samples were positive for PEDv but, when we looked at the infectivity values, depending on the layer of the lagoon that we were looking at, it was different.
In the top layer of the lagoon most of the virus, even if they were present, they weren’t infective. But, toward the middle layer of the lagoon and bottom layer of the lagoon, we find more infective virus and the percentage was variable, between 12 percent to 30 percent, depending on the farm and the site that we were looking at.
The study started in September 2014 and the 9 month period that I mentioned, it continued up to July 2015 so, by the time we were entering into the summer, the infectivity rate of the virus was going down showing that the environmental condition, higher temperature, UV sunlight probably are impacting the pathogenicity of the virus and reducing that.
Dr. Khafipour says the study shows producers need to be cautious when dealing with stored manure following a PED outbreak and he hopes it will stimulate research aimed at developing disinfects that will be more effective in dealing with virus.
