Dee: African swine fever outbreak in China major threat to US pork
News that China broke with African swine fever (ASF) generated great concern for many in the US swine industry, including Scott Dee, DVM, Pipestone Veterinary Services.
“This is a very challenging situation,” Dee told attendees at a recent swine-health conference in Macomb, Illinois. “ASFV is a very tough virus…and difficult to clean up should it get into a premise.”
No treatment or vaccines are available for ASF, which can cause up to 100% mortality. Surviving swine continue to shed the virus. The virus only affects swine and generally spreads through oronasal contact and not aerosol. It also is spread by a tick (not found in the US) and in contaminated feed, feces, water, meat and uncooked garbage.
Along with Megan Niederwerder, DVM, Kansas State University, and Diego Diel, DVM, South Dakota State University, Dee worked on research that proved viruses, including ASFV, survive in feed products shipped from Eastern Europe to the US.
Under the conditions of the study, ASFV survived in several feed ingredients, such as soybean meal, and pork sausage casings, as well as in an empty container during a 30-day trip across the Atlantic Ocean.
With nearly 2 million metric tons of ag products including feed shipped to the US from China every year, the risk of spreading a virus like ASF in feed is significant, Dee added.
“We have to do something different with our feed imports,” Dee stated. “We need a safe means to introduce essential products from countries of high risk.”
Pipestone is proposing the concept of “’Responsible Imports,’ which is a science-based means for safely introducing essential feed ingredients from countries of high risk,” he explained. Dee hopes the industry will band together to develop a standardized protocol for importing feed products responsibly and with reduced risk.
For example, feed additives or mitigants could be used in a protocol to reduce viral loads in feed. Preliminary research on mitigants showed several performed well against viruses like Seneca virus A and porcine epidemic diarrhea virus (PEDV), according to Dee.
In combination with mitigation, calculated periods of storage could be used to enhance viral decay over time under well-controlled conditions.
“The concept of ‘Responsible Imports’ provides a platform for discussion and the development of plans,” he continued. “Do we need to consider the possibility of designing designated facilities, product quarantines where products sit until deemed safe, based on estimates of viral half-life?”
Market pressure for change
“We are at a moment of truth in the industry where we need to work together,” Dee stated. “[ASF] is an old virus and not much new information has been generated lately. We need science to lead the way along with applying what we learned from PED.”
Dee is very pleased with the high degree of collaboration across feed manufacturers, government agencies, universities and private industry.
“We are really working together; everyone is stepping forward. The clans are uniting!” he concluded.