Update on African Swine Fever

By Jennifer Ryan

May 2019

Image of a pig

It’s not in the United States (yet), but distributors and veterinarians should be on alert

The responsibility for preventing losses from disease outbreaks can extend far beyond the boundaries of a single hog operation. In the case of African Swine Fever (ASF), multiple governments are working together to limit the spread of the disease. The reason is largely due to the strict international trade restrictions imposed on countries with confirmed cases of ASF. 

The United States has never experienced a case of ASF. If the disease crosses the ocean, losses could be as much as $8 billion for the pork industry in the first year alone, according to calculations from Iowa State University. That doesn’t include related losses of up to $5.5 billion for affected commodities.

Risk from feed ingredients

Each country assesses its own risk for foreign animal diseases, like ASF, and enacts import restrictions accordingly, explains Paul Sundberg, DVM, director of the Swine Health Information Center.

In the United States, import restrictions are not based solely on identification of ASF cases, he notes. For example, China announced the nation’s first case of ASF on Aug. 3, 2018, in a northeastern province of the country. However, the U.S. continues to receive some agricultural products from the country, including processed meats, soybean meal, amino acids and vitamins.

“It’s up to the pork industry and pork producers to ask their suppliers about the sources of their feed ingredients and then apply holding times or other practices that would decrease the risk of contamination with viruses like African Swine Fever,” Sundberg says.

Imported feed ingredients are a potential risk for ASF transmission, he says. 

Research beginning with porcine epidemic diarrhea virus (PEDV) transmission showed certain feed ingredients can allow other viruses to survive even after either trans-Atlantic or trans-Pacific shipping to U.S. ports. Furthermore, viruses can sometimes survive on to locations likely to manufacture feed for swine, according to information from the National Pork Board.

7 critical points for suppliers

Swine industry experts compiled seven critical points for pork producers to raise with their feed and feed ingredient suppliers:

1. Describe the facility’s biosecurity program to minimize the spread of pathogens from people, vehicles and ingredients.

2. Describe the facility’s employee training on feed safety.

3. Describe the facility’s pest control program.

4. Describe the facility’s traceability program.

5. Describe the facility’s supplier approval program.

6. Is the facility certified by a third-party certification body for food safety? Third-party certification programs may include the Feed Additives Manufacturers (FAMI-QS), the International Organization for Standardization (ISO), the Safe Quality Food (SQF), Safe Feed/Safe Food, etc.

7. Does the facility utilize ingredients that were manufactured or packaged outside of the United States?

Distributors can proactively address these points with their suppliers, so they are prepared for the discussion with their customers and to ensure their producer and veterinary customers receive low-risk products, Sundberg advises.

  • • African swine fever (ASF) cannot infect humans by meat or any other means.
  • • ASF is a highly contagious viral disease of pigs.
  • • All members of the pig family are susceptible, including feral swine and wild boars.
  • • The disease occurs in many African countries. Outbreaks have also occurred in other parts of the world, including Central and Eastern Europe, Russia and China.
  • • ASF has never occurred in the United States.
  • • It can be transmitted through direct contact with infected pigs, their waste, contaminated clothing, feed, equipment, vehicles and, in some cases, ticks.
  • • There is no vaccine or treatment for ASF.

The spread of ASF

The disease causes severe illness and high death rates in exposed pigs of all ages. Signs can include high fever, decreased appetite, weakness and reddened, blotchy skin. Other signs in pigs may include diarrhea, abortion, and respiratory illness, according to the Iowa State University Center for Food Security and Public Health.

“ASF is a much more slowly moving virus than PED, for example,” Sundberg says. “You won’t expect it to spread like wildfire through a country or area unless people move it. It will spread much more methodically and continually. Official reports from the Chinese government state the ASF outbreak there is under control, and they are releasing areas from quarantine. The government is optimistic they are on the other side of the outbreak. But other, unofficial, sources indicate that the illness is widely under reported in China, and it continues to spread throughout the country.”

A recent Swine Disease Global Surveillance Report noted China officially now has 25 provinces officially reported as infected with ASF. In addition, Mongolia reported its first outbreak of ASF – making it the second Asian nation to report the disease. 

Australia, South Korea, Japan, and Taiwan have reported the identification of ASF in confiscated products at ports of entry since August 2018 and have introduced tougher measures at points of entry. 

Protecting against ASF

If ASF is identified in the United States, there is a national response plan that has been developed by USDA Veterinary Services. The National Pork Board also has been working closely with the National Pork Producers Council, the American Association of Swine Veterinarians and the Swine Health Information Center to monitor the global situation and collaborate with the USDA. 

“We are working to address ASF and mitigate the opportunity for this disease – and viruses to come,” Sundberg says. “We’re exploring HACCP-type programs for feed safety and block chain systems to that will help with record-keeping. Ideally, we would like all feed product movement recorded and validated so producers and distributors can know how long the product has been in commerce and how it’s handled. While that might be an additional cost for the chain, it’s one of the most cost-effective measures for preventing diseases like ASF.”  

1 Spickler, Anna Rovid. Fast Facts: African Swine Fever. Iowa State University Center for Food Security and Public Health. November 2018 (Last Updated).

The National Pork Board, National Pork Producers Council, the American Association of Swine Veterinarians and the Swine Health Information Center have provided producers with information to help determine holding times for feed ingredients to reduce the risk from pathogen contamination. 

  • • Feedstuffs manufactured, sealed, handled and shipped under biosecure conditions that produces a product free of pathogens and prevents post-processing contamination are not a risk to animal health.
  • • Feedstuffs may become contaminated if not produced under biosecure conditions, produced under unknown conditions or not sealed to prevent post-processing contamination. The time between manufacture and use (holding time) gives an opportunity for viral contaminants to naturally degrade, so as not to be infectious.
  • • Current research shows a holding time of 78 days after the date of manufacture and bagging or sealing to prevent additional contamination (“born on date”) for amino acids, minerals or vitamins will degrade 99.99% of viral contamination.

For more information, visit the National Pork Board’s compilation of foreign animal disease resources at https://www.pork.org/production/animal-disease/foreign-animal-disease-resources.