ATLANTA, GEORGIA, US — An outbreak of African swine fever in the United States would be devastating in terms of animal loss and economic impact, which is why the livestock and feed industries must have a plan in place to contain and eradicate the virus, should it find a way in, said Cassandra Jones, professor/ASI teaching coordinator, Kansas State University.
“These are pretty extreme measures, but we don’t have the option to move to a vaccine or treat this,” - Cassandra Jones, Kansas State University
Jones reviewed the preparedness of the United States should there be an ASF infection, including the likely planned response as well as some challenges to consider, during a biosecurity session at the International Production & Processing Expo (IPPE) this January in Atlanta, Georgia, US.
Calling it the armored tank of viruses, Jones said ASF is an extraordinarily stable virus that doesn’t degrade in typical environmental conditions. Additionally, there can be several weeks between infection and clinical symptoms and no vaccine or treatments are currently available.
In the event ASF was detected in the United States, the government would likely issue a 72-hour stop order on animal movement so that it could assess the location of the virus. It would then practice “stamping out” the infected animals and animals within a certain radius of those.
“These are pretty extreme measures, but we don’t have the option to move to a vaccine or treat this,” she said.
ASF would not just impact the swine industry, but the entire agriculture industry, Jones said. In southeast Asia, ASF collectively dropped pig feed sales and manufacturing by about 50%.
“Even as we’ve seen entities try to rebuild and restock populations, we continue to see the overall domestic feed supply being year-on-year lower because of these significant challenges in animal health that the disease continues to bring,” Jones said.
The planned response for any foreign animal disease would include containment, eradication and business continuity, Jones said. Containment includes detection, control and outbreak containment as quickly as possible.
If an animal exhibits signs of a foreign animal disease, an investigation would begin with the animal health official visiting the site and collecting samples. If samples taken from the symptomatic animal are positive, it is considered a presumptive positive.
The state would begin an epidemiological investigation, including what has moved onto and out of that site over the past 30 days. Additional analysis also would be done to confirm the test results.
If a second sample tests positive, it is considered a confirmed positive sample and some significant decisions need to be made, Jones said. The US Secretary of Agriculture would be expected to declare an extraordinary emergency, which gives it some additional authority and access to different resources.
The infected premises would be quarantined, and control zones established with enhanced biosecurity around those areas and restricted access in and out.
“There would be a national standstill on the movement of pigs,” Jones said. “It’s expected to be at least 72 hours. That is not something to be taken lightly. It allows all state and federal officials to take samples of the animals where they are located and be able to make better decisions of which areas of the country can reopen to regular movement.”
Active and passive surveillance activities would be established so control zones can be made as small as possible, Jones said.
“We may start with the size of the state, then with sampling and surveillance, we would be able to narrow that closer and closer, maybe to an individual farm,” she said.
Jones said during the standstill it’s unlikely that feed deliveries will be stopped. That means it may be necessary to deliver feed to a known-positive premise to ensure animal welfare is maintained until euthanasia can happen.
There’s not a clear answer on whether swine-based ingredient movements will be stopped, Jones said. It is expected that FSIS-inspected facilities (raw and processed pork) will be exempt from movement restrictions. However, products from Food and Drug Administration inspected rendering floors (porcine meat, bone meal and choice white grease) may be restricted.
Eradication uses strategies that stabilize animal agriculture, the human food supply, the economy, public health and the environment. There would be mass depopulation of infected premises, cleaning and disinfection of any cleanable materials.
Feed on an infected farm is not considered cleanable, so if feed had just been delivered to that farm, it would have to be disposed of safely. There are limited options available, Jones said. Ideally, it could be composted on site, but it’s unlikely a facility would have enough room for carcasses and feed.
“Feed and the pig themselves don’t mix very well,” she said. “The perfect mixture to break down carcasses is high in fiber and that’s not something in swine feed. Carcasses would have priority, so we have to find options to move feed off site.”
The feed would need to be transported as biohazardous waste to a permitted landfill. Other possible options for feed disposal include fixed incineration or open-air burning.
Rendering carcasses may be difficult because the facility would need to have enhanced biosecurity where personnel cannot move from “dirty” to “clean” areas without decontamination. Not all facilities are prepared to do that, Jones said.
Rendered products from carcass disposal could be used in pet food, if specifically authorized, she said, otherwise it would have to be disposed of through composting, landfilling or recycling at a cement kiln.
Business continuity provides science- and risk-based approaches to restart business for non-infected animals and non-contaminated products.
Business continuity provides science- and risk-based approaches to restart business for non-infected animals and non-contaminated products, Jones said. For pigs, the Secure Pork Supply Plan provides guidance for the managed movement of animals.
It requires that the premises of origin and destination have a National Premises Identification Number (PIN) along with enhanced biosecurity measures and traceback/forward information confirming the origin is not an infected, suspected or contacted site. Surveillance would need to confirm no evidence of infection. This includes active observational surveillance for at least seven days; negative diagnostic tests within 24 hours of movement; and visual inspection of animals by a regulatory official.
Business continuity is a gap that the feed industry can start making some progress on in terms of providing some of the science- and risk-based approaches to facilitate continuity of business, Jones said.
“What happens to the feed and to the ingredients in the rest of the country and non-contaminated products?” she said. “How quickly can we restart movements of everything else, and how many products would be affected by some sort of shutdown?”
It’s not clear whether feed movements would require a permit similar to animal movements, Jones said. Some states have said during disease response exercises that they plan to permit feed deliveries to swine facilities.
“The feed mill would have to have a PIN and implement enhanced biosecurity protocols,” she said. “Other states have said it’s a much lower risk and they don’t have the capacity to manage animal and feed movements.”
It’s not certain whether permitting would extend to ingredients, but Jones said it is unlikely.
“This is perceived to be a low-risk use and I would expect any of this permitting to only occur if there is sufficient permitting capacity,” she said. “Initially, permits for animal movements will be prioritized.”
Several questions remain in the situation where a feed mill delivered to an infected, suspect or contact site, Jones said. There is currently no business continuity plan for feed, which means there is no guidance for enhanced biosecurity or surveillance.
“There is no validated testing protocol for any ingredient or feed, which is a required part of permitted movement of other products,” she said.
The FDA has expressed concern about farm-to-mill-to-farm movements and possible incidental leaks in biosecurity.
“The quicker that we can go through the containment, eradication and business continuity stages, the faster we can get to reopening movement and get back to business as usual,” Jones said.
Feed industry preparedness
The feed industry should examine what it can do now to prepare for ASF or any foreign animal disease. Feed mills that supply swine-based clients could look at obtaining a PIN number from a state animal health official. She also suggested having a biosecurity plan in place, such as the ones being developed by the American Feed Industry Association.
She also recommended developing and practicing a biosecurity plan that could be put in place in the event of an ASF infection.
“What happens and what will you do if a feed mill is inside a control area?” she asked. “What would you do if you receive delivery trucks or have feed trucks that deliver through a control area? Or deliveries to swine farms that are within a surveillance area? What about if you deliver to non-swine farms inside a control zone and also have deliveries outside of the control zone? These are some pretty significant questions as to what we need to be doing to the outside and inside of delivery vehicles to make sure we don’t have contamination in traffic.”
The swine industry has been proactive in developing its own voluntary program to work through the steps in a fast and deliberate manner, Jones said, and she proposed that a similar industry-led playbook could be created for the feed industry.
“We don’t believe that feed or ingredients are the most likely way disease enters the US, but it is a likely way that it can be spread,” she said. “A Secure Feed Supply Plan could potentially help limit that spread.”
She asked participants to take a five-minute survey to share their opinions on creating such a plan and what it could include.“We’d like your opinions on whether we should be looking at implementing something like this and what are some of the initial things we should be deciding in that,” Jones said. “We’re hopeful that something like this could help maintain access to domestic and international markets during an outbreak and increase the speed to restore continuity of business.”