Results expected in months | Researchers focus on how virus is shed, sow immunity and how much resistance is required
OMAHA, Neb. — The U.S. pork industry has accelerated research into porcine epidemic diarrhea to get answers about a disease that has killed millions of young pigs in less than a year.
Research projects that might have taken years are now expected to produce results within months, said Lisa Becton of the National Pork Board.
“This is a new virus in the United States and we had absolutely no information about its pathogenicity and survivability,” she told a special session of the National Institute for Animal Agriculture meeting held in Omaha April 1-4.
Twenty-eight states have reported cases with Vermont the most recent. About 4,700 cases have been diagnosed, although it is not known how many individual farms or pigs were affected, said Becton.
The disease was found in Canada in January, and researchers in the United States are working with Genome Alberta to learn more about its genetics and susceptibility. About $500,000 is available for the work.
More than $1 million was spent last year on eight projects to study the basics of the disease, which was probably circulating in April before it was confirmed as PED in May.
“If you don’t know very much about the virus, it makes it nearly impossible to figure out how to go to the next step of containment, management and elimination,” Becton said.
Researchers are focusing on how the virus is shed, how it affects sow immunity and what level of resistance is needed for protection. They also need to know how long immunity might last.
Other research is evaluating disinfectants to deactivate the virus.
Feed contamination was discussed late last year when some suspected the disease might have been transmitted in dried blood plasma used in pig starter.
No trials showed infectivity in dry feed at that time, but the research has continued.
A feed consortium meeting held in Iowa March 19 discussed immediate needs for feed research, collaboration and support for the industry.
Manufacturers are willing to conduct risk assessments at all steps within the feed processing and delivery chain to develop best manufacturing and management practices to prevent feed contamination.
Risk assessments should also include the potential role of birds, rodents and other potential sources, such as clothing or other inanimate objects.
Money has gone toward producer communications and information for people attending sales and shows.
Becton said the pork board did not want to cancel hog shows this summer, seeing the events as good ways to expose the public to pigs and gain support for junior programs.
Guidelines on areas of risk have been published for exhibitors.
About $150,000 has been spent to develop better diagnostic tests.
The Veterinary Diagnostic Laboratory at Iowa State University received its first sample of a questionable disease April 14, 2013. Butch Baker of the university said it took time to figure out what it was, but it was confirmed as PED by the beginning of May.
The lab also found the delta corona virus, which causes similar symptoms.
Researchers know that different strains of the PED viruses are circulating in the U.S., but they don’t know if the two strains arrived at the same time or evolved once they landed here.
“We just don’t know how pathogenic this virus is and whether there are co-viruses” he said.
It is speculated that the virus originated in China or Southeast Asia, said Paul Sundberg, a veterinarian and vice-president of science and technology for the National Pork Board.
Transmission and biosecurity are focal points for task forces set up to combat the disease. Committees are made up of packers, producers, veterinarians and government.
A survey of packing plants, which started last July to track traffic going in and out of facilities in the Midwest, showed the virus can likely be transmitted within a facility.
Spontaneous outbreaks on unrelated farms present another un-known.
“What we continually hear from the field is unexplained outbreaks,” he said.
“They just don’t seem to make any sense.”
A rapid response team was formed to investigate outbreaks of PED and deltacorona viruses at different sites to determine why this infection happened.
Humans, vehicles and feed pellets were considered moderate risks, while transmission in the air, water, artificial insemination and veterinary supplies and bedding seemed to be low or negligible risk.
Regular research updates are posted at www.pork.org/PED.