Consumers may experience sticker shock at supermarkets this summer as they shop for bacon, ham and other pork products because of a virus that has killed more than 7 million baby pigs across the country, including Minnesota.

Pork prices are 15 percent higher than one year ago, and they're likely to shoot higher soon. U.S. hog futures, which have soared 50 percent this year, set a new record last week. Federal officials recently announced new mandatory reporting requirements effective immediately to get a better handle on the disease.

Porcine epidemic diarrhea virus (PEDv) likely originated in China, but no one knows how it entered the United States in May 2013, or how long it may take to control it. The highly contagious disease has spread to 30 states and infected an estimated 50 to 60 percent of swine farms.

The stakes are high for Minnesota, the nation's second-largest pork producer after Iowa, and home of two large pork processing plants: Hormel in Austin and JBS in Worthington. The virus spiked in Minnesota during the heart of winter and is still infecting herds, although at a slower pace.

"This is an extremely big deal," said Jim Collins, director of the Veterinary Diagnostic Laboratory at the University of Minnesota. "It's extremely important to the swine industry in Minnesota, which is a huge agricultural business."

Several hundred Minnesota farms have been affected by the virus, according to the U's College of Veterinary Medicine, and Minnesota has the second-highest number of positive cases in the country, as reported to the National Animal Health Laboratory Network.

The virus has alarmed and frustrated the swine industry, since there is no vaccine to prevent the disease. Farmers have ratcheted up biosecurity to keep their farms isolated, or in some cases to prevent the disease from reinfecting their herds.

Despite all the concerns, the good news is that PEDv is infectious only to swine, and is not a food safety concern, said Dave Preisler, executive director of the Minnesota Pork Producers Association. "It's not a disease that affects other animals, and it's not a disease that affects humans," he said. "Because of that, it has had no effect on exports."

Feds take action

Earlier this month the U.S. Department of Agriculture acknowledged the "significant impact" of PEDv and two other swine viruses that have been discovered in recent months. Because pigs have no initial immunity to the viruses, officials said, "the U.S. swine population is at risk."

A federal order effective June 5 requires pork producers, veterinarians and diagnostic labs in Minnesota and elsewhere to report confirmed detections of the disease to USDA or to state animal health authorities. Some herds that had the disease are becoming reinfected, officials said, so mandatory reporting is needed to identify the total number of infected herds and where they are located. The order also requires farmers with diseased herds to provide a plan of how they're managing the problem through monitoring and various biosecurity measures, such as controlled access to farms and disinfection of facilities.

USDA also announced a $26 million package that includes research dollars to help develop a vaccine for the virus, and cost-share funding for pork producers who need to ramp up their biosecurity.

Closer monitoring is already a fact of life for Kevin Hugoson, who estimates that he lost about 1,250 baby pigs in February and March at one of his farms near Fairmont in south-central Minnesota.

"The intensity of the virus is just off the charts," said Hugoson, who has 750 sows on his home farm. "It moves very easily. You just need a little speck maybe on your shoe and that could contaminate your whole herd."

The virus spreads through manure and perhaps through feed slightly contaminated with manure. Hugoson said he has boosted biosecurity "fivefold" on the farm to regain control. Swine farms always use disinfectants to reduce the possibility of any disease that can spread like fire in confined feedlots, but Hugoson said he has clamped down even more on access to his farms, and his workers are being especially diligent to wear disposable booties and wash out trailers and other vehicles that have transported hogs.

How it works

The virus is picked up by nearly all pigs, but it only kills the youngest piglets. "Pigs are born healthy, they look fine, and then they'll get a couple days old and if they've been infected with this, everything goes right through them and they just dehydrate to death," said Preisler.

Older pigs and hogs may get sick for a few days and stop gaining weight, but they usually recover, he said.

Infected sows develop immunity about 20 days after exposure to the virus, so the animals in greatest danger are newborn pigs and pigs born during the first three weeks after the disease enters a farm — before immunity can take hold. In most cases 80 to 100 percent of the piglets die after acute outbreaks of severe diarrhea and vomiting.

Hugoson, who has raised pigs since 1985, said his farm is back to normal production. But that's not true for about 20 percent of herds nationally, he said, that don't seem to develop full immunity and have experienced continuous losses. And Hugoson doesn't know whether the virus will return to reinfect his herd during the winter months when PEDv is especially virulent.

University of Minnesota researchers scrambled last year to develop a rapid response diagnostic test to tell whether pigs have PEDv, and by February had developed a test to indicate whether pigs had developed antibodies to the virus. Now scientists in Minnesota and elsewhere are racing to come up with a vaccine to prevent the disease.

Bill Hartmann, Minnesota's state veterinarian, said a vaccine would put the industry in a much better situation. "Right now the tools they have to fight this disease aren't working very well," he said.

In May the Minnesota Legislature allocated $200,000 for research to prevent and cure the virus, but Collins said much more will be needed from industry and other sources. Some vaccines will be coming out soon for field testing, he said, but it may be several years before an effective vaccine will be widely available. The university is also studying how transportation and feed might be playing a role in how the virus moves around, Collins said.

After the virus was discovered in Indiana, it killed piglets on large farms in Kansas, Oklahoma, and North Carolina before moving to Minnesota and Iowa.

Market impact

Officials estimate that the loss of pigs has reduced the normal number of hogs coming to market by about 5 percent nationally. Justin Roelofs, financial services officer for AgStar Financial, said many farmers have been growing their hogs about 7 pounds heavier to offset that loss, so the overall effect on the market has been only about 1 percent less in total pork production.

But Roelofs, who specializes in swine, expects the lag effect of piglet die-offs in Minnesota and Iowa early this year to be noticed in the second half of the summer, when the national decline in hogs may reach 10 percent.

"We're going to see more of a shortage that will show up at the meat case then as far as higher prices," he said.

Preisler said the national decline in hogs coming to market has caused some meatpacking companies to cut back production and employee hours in some states, but not yet in Minnesota.

He said there have also been "extensive discussions" about whether swine producers will avoid bringing pigs to county and state fairs this summer because of the virus. "There's nothing we're aware of where a show has been canceled," Preisler said. "At this point there is nothing that will change other than some really heavy education on biosecurity."

The upside of the PEDv virus is that high market prices will be good financially for many pork producers, Roelofs said, unless their entire business is raising sows and baby pigs.

But even for those having a good year, the virus is troubling and frustrating, he said.

"Producers don't like to lose animals," Roelofs said. "They don't like it in the worst way."

Tom Meersman • 612-673-7388