Animal feed mixed from ingredients sourced around the world could be carrying more than the vitamins and nutrients livestock need. Seven different viruses that could cause widespread illness and big economic losses for meat producers in the United States can survive in certain imported feed products.
A study published in March in the journal PLOS One looked at 11 viruses that are not yet in the U.S. but infect herds in other places, such as African swine fever and foot and mouth disease.
Lead researcher Scott Dee of Pipestone Veterinary Services in Minnesota and colleagues from various universities and laboratories mixed samples of each virus with several frequently imported feed ingredients, such as soybean meal, certain vitamins and even pet food.
Those samples were subjected to simulated temperature and humidity conditions for journeys to the U.S. from an origin country — say from China across the Pacific and then over land to Des Moines, Iowa.
Seven of the viruses could survive in at least two of the tested ingredients, according to the study.
“I think what the feed did was, it protected the virus from our environmental conditions that we created during the study,” Dee told Harvest Public Media.
Each virus was also put through the test without an ingredient and they didn’t fare as well.
“Except for Africa swine fever virus, it seemed that all the other viruses need a feed ingredient to kind of protect them if they were going to survive,” he said.
The study started with pigs — following the 2015 porcine epidemic diarrhea virus (PEDv) that wiped out six million piglets and came from China. Funding came largely from the Swine Health Information Center, but Dee said many of the viruses affect other animals as well.
“We realized, gosh, we were working with diseases of other species, too, such as ruminants, poultry and people,” Dee said, though the two that could infect people, influenza A and nipah virus, didn’t survive the trial.
Foot and mouth disease did. It’s been absent from the United States since the early decades of the 20th century, and officials would like to keep it out as it has the potential to spread rapidly and kill large numbers of cattle, hogs, sheep and other animals.
Iowa State professor and veterinarian Jim Roth helped developed an emergency preparedness plan for the pork industry in the event that a fast-spreading foreign disease is detected here. Though he was not involved with the study, he says the results are interesting because they demonstrate that feed imports could be a source of infectious disease.
“Now, on balance, we’ve been bringing in feed from China, the same feed ingredients, for many years,” he said. “China has had FMD — foot and mouth disease — all of those years and it hasn’t gotten here in the feed.”
The risk is there, he said, but it’s not imminent, and more research is needed.
Dee said he’s next looking at safe ways to prevent potentially infectious ingredients from arriving. For now, though, he says importers should be on alert, suggesting that those importing feed may want to look beyond getting the cheapest price and consider the disease-status of other countries.
“It’s in the hands of USDA, the FDA, APHIS [USDA’s Animal Plant Health Inspection Service], FBI even. People are very interested in it.,” Dee said, adding that he’s met with members of the FBI.
“[It’s] pretty hard to refute the fact that this could be a significant risk factor for pathogen transport between countries,” Dee said.
The study included research from South Dakota State University, Kansas State University, Iowa State University and other labs.