As of Monday, there have been 16 reported cases of PED-infected barns in southeastern Manitoba. For those not involved in the operations of a hog farm, there may be questions surrounding the PED virus from what it is to why it's a big deal for farmers and whether or not the meat is still safe for consumption. Mark Fynn is the manager of quality assurance and animal care programs for Manitoba Pork, he helps answer those questions.
What does PED stand for?
“PED stands for Porcine Epidemic Diarrhea, which is a virus.”
How are pigs affected when they are infected by this virus?
“When they're infected by the virus they'll generally get diarrhea, they'll go off feed, and some animals will vomit. It's basically a gastrointestinal sickness. It affects different ages of pigs differently. With really young pigs, those that are under seven days old, it affects their intestines quite a bit so that they can't absorb nutrients. Unfortunately, we see some pigs die because they can't get the nutrition and the hydration they need.”
Which pigs are most likely to have a higher severity level and are more likely to die from this virus?
“The ones that are more likely to die and have a higher severity are those piglets that are under seven days of age just because they can't absorb nutrients or water.”
Generally, do pigs just work through a virus like humans do and then they're fine again?
“Yes, it's exactly that. So, when they get infected by the virus they'll start building immunity, their immune system will start trying to fight it and after a certain amount of time, they're able to overcome it if they survive through that. Like I said if they're over seven days of age most of them are able to fully recover.”
How does the virus spread not only from pig to pig but also from barn to barn?
“The virus spreads mostly in the manure, so the virus is shed in there. If a pig who hasn't experienced the virus before comes in contact with another pig's manure, they can get the virus and go through the same kind of stages as previous pigs. So, anything that can transfer around the manure could be a potential carrier or vector. So we see things like the transportation trailers or any equipment that moves from farm to farm or people that carry it on their footwear. Anything that can move it from farm to farm can infect the pigs and it doesn't take much of the virus to actual infect a pig.”
So it's a pretty strong virus?
“It's a very strong virus. To give you a sort of sense, there are millions of copies of the virus in one millilitre of manure and it only takes 72 copies to infect a pig.”
What's the usual duration of this virus?
“Duration of the virus, so, the pigs that get impacted by it, when they first come in contact, it usually only takes one day for the pigs to get sick and start shedding the virus through their manure. That will usually last three to six weeks, where they will be shedding. But because of how strong the virus is and how easy it is to infect other pigs, even though the pigs might get healthy and recover, there's still lots of the virus around in the environment, in the barns, on equipment, and those things. So, you have to really do a good job of cleaning and disinfecting all that stuff before you move it to another site with pigs.”
What are some preventive measures to stop the spread?
“The first thing you want to do is contain it on one site and get all the pigs through it together so that they stop shedding. At that point, you're looking at doing a full cleaning and disinfection. We do diagnostic sampling, like swabs, to make sure it's been fully removed from the site. But, we have a lot of vehicles and people that move around too so we need to make sure we're taking steps to prevent equipment and footwear from moving to another site without being cleaned and disinfected. So, we really focus on trying to dedicate things like equipment and footwear to each barn so we're not carrying it along, so we don't have to rely on the cleaning and disinfection to be the only step to prevent the virus from moving around.”
What do they do with the infected manure?
“With the infected manure, they end up spreading it just like we would with regular manure. There really isn't any special process that we follow with that. We try and wait as long as possible and we try to minimize the equipment that's used on that farm to spread it and prevent it from moving to another farm. But there's not really any special procedures we're following above and beyond what we have. So, there hasn't been any indication with the farms that we've seen a break with it, that there's strong connection to manure spreading from previously infected farms.”
There's that white powder that farmers have been spreading across their driveway entrances ...
“So, a lot of people are using hydrated lime. Hydrated lime has been shown to be effective at dealing with a number of different viruses and diseases. When a virus or disease comes into contact with it, it will basically denature it, all it's genetic material, and so it shouldn't be able to pass around. A lot of people have been using it to try and disinfect tires or people walking into sites, by doing that. It does require that that stuff get replaced fairly frequently because as soon as it comes into contact with moisture, it quickly breaks down, so it needs to be dry powder. So you'll see a lot of driveways with that on it and people replacing it quite frequently.”
Do you know where this virus originates from?
“I'm not sure where it was first discovered, there are different strains of the virus. The strains that we have looked at so far have had been very similar in sequence to what has been seen in the initial strain that was in the U.S. And that has been shown to be very similar to a strain that was in China before. So, we have a feeling that the virus that initially got brought into North America was likely of Chinese origin. But we know we likely brought this up from the U.S. There's been a decent amount of research that suggests that the virus can survive or is even protected in certain feed ingredients and there are a number of feed ingredients that are imported from China into North America. So, there's some thought that that could be the case. There's also a decent amount of foot traffic as well, people going back and forth. People even within the industry going back and forth. I think the thought is that the most likely cause would have been feed ingredients that are coming from China.”
After a pig goes through the stages and is healthy again, is the meat still edible?
“Yes, the meat is still edible. There is no food safety concern. Like I said, it's a gastrointestinal disease, so that's really what it impacts, similar to other stomach bugs that we would deal with. It doesn't affect humans, it can't be transferred to humans. We have a bunch of swine workers that work directly with these pigs as they go through this sickness and there's no impact on people's health. The meat is safe to eat, so no issue there. The biggest concern is with the pigs and getting them through the sickness.”
Is there any way these pigs could make it to slaughter while being infected?
“When they're actively shedding and they have clinical signs we make sure they're not shipped. There are two things there. For the welfare of the pigs, we don't like moving them when they're clinically sick. We also don't want to be spreading it around. So if they're actively shedding and we're transporting them, there's always a chance of contaminating the environment, potentially roadways, and that sort of thing. So we want to prevent other pigs from getting sick as well.”
So, it sounds like it wouldn't happen, but let's say someone would consume meat from an infected pig, would that do anything to them?
“No. Like I said, there's no impact on food safety or of public health. The virus is really only active in the gastrointestinal system of the pigs, so it's not getting into the meat there. In addition to that, it doesn't affect people, so there's no issue with people eating the pork from these animals.”
What does an infected barn or farm mean to the owners financially?
“There is a big financial hit to this. One of them is that we don't want to be spreading the virus around to other pigs, to other farms, so we try to limit the contact with facilities such as the processing plants that have contact with other farms. So, a lot of times we have to find an alternative market for the pigs, other than the two main plants in Manitoba. So there's an opportunity cost in doing that, or a market loss in doing that. And then also the cleaning and disinfection and all the bio-containment that they do on site has some impact there. For a typical commercial barn, you're probably looking at somewhere between $200,000 to $500,000 going through one of these outbreaks while we try to biocontain it.”
If the virus runs its course and then the animals are healthy again. Some people are wondering, why is it such a big deal?
“The big deal is really in the pigs that it impacts, especially those piglets that are under seven days of age. You have a lot of pigs in the province that are going to be in that age range, so if it hits one of those farms we, unfortunately, lose a lot of pigs because of that. That's probably the biggest economic cost, and then there's the clean up of things. So, we really want to minimize the number of farms that have that age range of pig on there, so we're not losing those pigs.”
Was there anything you wanted to add that you thought was important for people to know?
“We're trying to put in as many efforts as possible to keep it on the farms that already have it and try to help those farmers through this. So, like I said, we can move it around, unfortunately, but manure and that sort of thing. So, we recommend, for those people that aren't involved in the industry, and for those that are as well, that we try to minimize the amount of contact we have on the farms themselves, so we're not driving into the farmyards or walking to the farm yards and moving around. A lot of the things that we can do with those farmers, or the interactions we have with those farmers and services we provide we can do off the farm and that's a good way of preventing moving the virus around and helping those farmers out in the long run.”