CHICAGO, Feb 20 (Reuters) - As the U.S. hog industry struggles to contain a virus killing million of pigs across the country, the U.S. Department of Agriculture warned on Thursday that the impact on the hog supply would be greater than expected.
Montana and Idaho became the latest in 25 U.S. states and 3 Canadian provinces to report confirmed cases of the Porcine Epidemic Diarrhea virus, or PEDv. That brings the total confirmed cases in the U.S. to 3,528 as of Saturday, up from 2,962 as of Feb. 1, according to data released Wednesday by USDA's National Animal Health Laboratory Network (NAHLN).
USDA defines each diagnostic case as multiple animals at a single farm site or at several locations. The latest data showed that the number of weekly confirmed cases decreased slightly from a high of 301 in the week of Feb 2.
Although PEDv does not affect humans and is not a food safety risk, the virus's toll on pigs is trickling up the food chain in the form of industry financial losses and potentially higher pork prices for consumers.
"Mortality rates due to PEDv have been highest among young piglets, which have curtailed the growth in the number of pigs per litter and will likely slow expansion," USDA's chief economist Joseph Glauber said during the agency's annual outlook conference in Washington.
Older pigs have a chance of survival, but the virus kills 80 to 100 percent of piglets that contract it.
Some U.S. meat companies have said that the virus is driving up hog prices and cutting the pork supply by 2 to 4 percent. In the United States, the world's largest pork exporter with a 65.9 million head hog herd, retail pork prices still hover near record highs, and losses due to the virus are expected to keep boosting hog futures prices.
Analysts and traders have estimated up to 4 million pigs died from the virus, but the hog industry does not have an official death toll. The virus is reported voluntarily, so it could affect more states than has been documented, said Tom Burkgren, executive director at the American Association of Swine Veterinarians.
PEDv causes diarrhea, vomiting and severe dehydration in pigs. Research by the U.S. hog industry determined it is spread orally through infected pig manure, and can be carried by trucks, boots, clothes and water.
But feed containing porcine by-products, including but not limited to plasma, recently came into focus as a means of transmission. The Canadian Food Inspection Agency (CFIA) found the virus in samples of U.S.-origin plasma from a third-party manufacturer for Grand Valley Fortifiers, a livestock feed company based in the province of Ontario. The company recalled the feed.
"If there was some way that that feed got contaminated, we need to find out how that happened, whether there was a breakdown in normal procedures, or whether normal procedures need to be changed," David Meeker, senior vice president of scientific services at the National Renderers Association in Virginia said in an interview on Thursday. "All those things are being considered, but we just can not do much without more facts."
The U.S. hog industry has relied heavily on biosecurity measures as a means to curtail the spread of PEDv as pharmaceutical companies work to develop vaccines.
Harrisvaccines, an Ames, Iowa-based animal health pharmaceutical company, was among the first companies to develop a vaccine for the deadly pig virus. The company has 100,000 to 150,000 doses reserved for shipment to Canada.
"We're doing some efficacy studies in our lab facilities and those should be completed mid-March, then we should have some data," said Joel Harris, Harrisvaccines' marketing director regarding the success rate of the vaccine.
Research institutions have partnered with animal health companies to develop vaccinations. Zoetis Inc announced a partnership with Iowa State University this month. Merck Animal Health, a division of Merck & Co., also entered into a 12-month research agreement with Utrecht University to develop a vaccine. (Editing by Amanda Kwan)