Area scientists fight virus that is killing pigs by the millions
04/23/2014 10:22 PM
04/23/2014 10:22 PM
Animal medicine scientists in St. Joseph are hard at work trying to create a vaccine for the porcine epidemic diarrhea virus that is spreading across North America, killing piglets by the millions and raising the price of bacon at the supermarket.
Greg Cline, a doctor of veterinary medicine and technical manager for swine enteric disease at the Boehringer Ingelheim Vetmedica company in St. Joseph, said the virus poses no threat to humans who eat pork or those who work around pigs. But when swine herds contract the disease, virtually every piglet born for a month or more will die of severe dehydration.
That’s exactly what happened on Brent Sandidge’s farm near Marshall, Mo., starting in late January and continuing through mid-March.
Sandidge said he first noticed some young pigs suffering diarrhea on Jan. 29.
“The next day it was a whole bunch of litters,” Sandidge said. “It moved rapidly. We didn’t wean any pigs for quite a few weeks. It severely dehydrates them and they die. After that, we got immunity to it. Things are pretty well back to normal now, but we lost all our production for four to six weeks.”
Sandidge called a veterinarian, who took stool samples and confirmed the virus, known as PED. Sandidge had to implement a series of measures to try to stop the spread of the disease beyond his farm. He won’t have any market hogs to sell in July and August.
There is, as yet, no treatment for PED and no vaccine to prevent uninfected herds from contracting it.
The virus first showed up in the United States in spring 2013. Today it has been found in 28 states, including Kansas and Missouri, as well as Canada and Mexico.
“It’s just been a year in the U.S., and in that time we’ve developed a test for the virus and a test for recovery,” Cline said. “We’re researching how the virus is transmitted. We learn more every day about better ways to control its spread.”
Last week, the U.S. Department of Agriculture said it would step up its containment efforts by requiring farms to report infections and labs to report positive tests from submitted tissue and fecal samples.
The disease has been blamed for recent increases in bacon and pork prices. Farmers have struggled to control the virus, because little is known about how it spreads and there is not yet a federally approved vaccine.
To date, Cline said, 7 million pigs have succumbed to PED out of a U.S. pig inventory of 105 million.
Those numbers indicate the importance of finding a vaccine to protect the uninfected herds. The loss of pigs to PED is expected to increase the cost of pork products 10 to 20 percent by the end of this year, Cline said.
Cline has been studying the virus in his St. Joseph lab in hopes of developing a vaccine.
In addition, Boehringer Ingelheim recently established a partnership with the University of California-Davis to create aPED News
website to educate people in the industry. Modeled after the university’s FMD (foot-and-mouth disease) News, PED News collects stories about outbreaks, control measures and medical research and is updated daily.
“It’s a free subscription, and it brings news from around the globe right to your computer,” Cline said.
Steve Patterson is a vet in Shelbina, Mo., and he appreciates the PED News.
“We’re in a tremendous learning curve right now,” Patterson said. “I get calls every day from farmers who haven’t heard of it.”
Several of his clients have suffered outbreaks, and all of them lost a month’s worth of pig production.
“At that point, the sows will develop maternal immunity, and that gets passed on to the piglets,” Patterson said.
Patterson said PED is highly infectious and farmers have to learn and undertake new “biosecurity” measures to prevent its spread.
“You have to make sure we don’t carry it in on ourselves or on vehicles,” he said.
Trucks delivering, for example, feed or propane should now be washed thoroughly before they are allowed to enter a farm where pigs are raised.
“Trucks that haul pigs to slaughter plants have a high chance of coming back with PED,” Patterson said.
Patterson said the new biosecurity measures are being rapidly adopted across the industry.
“We need to try to clean and disinfect farms like hospitals,” he said. “With this virus, you can’t overclean.”
Ultimately, Cline said, “the solution for PED will be what can we do to decrease exposure and increase immunity. That’s true for any disease — be it dogs, cats, pigs or humans.”
Cline said he and his team are “working hard to bring creative innovation to market. We’re putting a lot of resources into this effort.”
Cline said Boehringer Ingelheim scientists are “turning over every stone” in the laboratory, experimenting with the traditional methods of producing vaccines — using both live and killed forms of the virus to try to produce immunity-giving antibodies.
Once they find what they believe to be an effective vaccine, they will need U.S. Department of Agriculture approval before they can commercialize it.
“Honestly, you want these things to take time,” Cline said. “That process is defined by the USDA so that when the vaccine comes to market, it will be safe and effective and not contaminated.”