African swine fever threat neutralized by collective action

Keeping African swine fever (ASF) out of the United States has been a priority for animal health officials and the swine industry. Once confined to Africa, the highly contagious viral disease affecting domestic and wild pigs has been reported in more than 80 countries since 2005.

Dr. Lydia Carpenter

Its incursion almost seemed imminent when, in July 2021, the disease reappeared in the Americas after an absence of almost 40 years, having been diagnosed in pigs in the Dominican Republic and later in Haiti.

According to the U.S. Department of Agriculture's (USDA's) Animal and Plant Health Inspection Service (APHIS), an outbreak of ASF could have an economic impact of as much as $15 billion due to collapsing pork prices, swine industry impacts, and lost export markets, so long as the disease was eliminated within two years. Under a 10-year scenario, damages could hit $50 billion and exports might never fully recover.

"An introduction of ASF would have devastating consequences, both for the health of our domestic herds and for the swine economy," said Dr. Lydia Carpenter, a veterinary medical officer with USDA APHIS Veterinary Services.

Dr. Carpenter played a pivotal role in the development and implementation of the U.S. Swine Health Improvement Plan (US SHIP). Launched by APHIS in 2020, US SHIP is a national certification program designed to prevent outbreaks of ASF, classical swine fever (CSF), and other diseases by setting biosecurity, traceability, and testing standards for the swine industry.

"The current US SHIP pilot program demonstrates the progress that can be made when industry, state, and federal authorities collaborate to address a common goal," said Dr. Abbey Canon, director of public health and communications for the American Association of Swine Veterinarians (AASV). "The AASV applauds the foresight by industry stakeholders to initiate the US SHIP program. The contributions of USDA APHIS Veterinary Services staff have been important in the development and maturation of the program, bringing it forward as a proposed rule. We also recognize and thank USDA APHIS leadership for supporting this industry-led effort and for seeing the potential value to U.S. swine health."

US SHIP building

US SHIP began after a 2018 study commissioned by the Swine Health Information Center and carried out by researchers at Iowa State University (ISU). The intent was to assess the potential for a program similar to the National Poultry Improvement Plan (NPIP) that would support the U.S. pork industry.

Results from the paper, "Case Study: Is it Time for an NPIP-like Program for the US Pork Industry?" found that the basic tenets and approach used by the NPIP "could serve as a road map for pork producers and slaughter facilities interested in more directly and systematically addressing the major swine health issues of high consequence and better positioning the future of the US pork industry in the domestic and global marketplace."

In 2020, the USDA officially announced the pilot project. It started as a joint effort among APHIS, ISU's Center for Food Security and Public Health (CFSPH), and ISU's Veterinary Diagnostic Laboratory (VDL).

Pilot project investigators, staff, and technical committees, which involved more than 90 subject matter experts and industry participants from across the U.S., drafted program standards for the first year of the pilot project.

At its core, US SHIP rests on three interrelated pillars:

• Biosecurity: Requirements designed to protect herds from foreign animal disease introduction. Dr. Carpenter emphasized that these measures benefit producers beyond ASF and CSF prevention. "Biosecurity is not always disease-specific," she said. "These requirements also reduce the burden of endemic diseases producers face every day."
• Traceability: Participating producers are required to maintain detailed animal movement records. This information is invaluable to state and federal partners during an outbreak. "If ASF appears on one farm, that movement data can help confirm exposures and implement mitigation measures more quickly to limit disease expansion," Dr. Carpenter explained.
• Sampling and testing: Surveillance is built into the program, allowing for early detection of foreign animal disease incursions. Combined with movement data and biosecurity practices, testing is intended to provide layered protection for domestic herds.

Like the NPIP, US SHIP is designed as a cooperative federal-state-industry program. The initiative includes a federal advisory committee and a governance structure that reflects the tripartite model.

Once African swine fever (ASF) reached the Dominican Republic and Haiti in 2021, it seemed just a matter of time before the highly infectious virus spread to the United States. However, the U.S. swine industry has observed rigorous biosecurity standards that have, so far, kept ASF at bay.

The US SHIP House of Delegates is a decision-making body of industry stakeholders and regulatory officials. They first met in 2021 and approved initial program standards that established content, direction, and requirements for certification. These have since been revised.

Where the programs diverge is in their focus. NPIP was created in the 1930s to address endemic poultry diseases. US SHIP, by contrast, was founded to guard against foreign animal diseases, with the potential to expand into endemic disease certification as the program matures.

Dr. Carpenter joined the APHIS swine health team in 2023.

From the outset, Dr. Carpenter's role was to ensure US SHIP had a robust regulatory foundation while maintaining the flexibility required for producers and states to participate. She worked closely with program stakeholders to draft policy language, conduct rigorous reviews, and prepare the regulatory framework for the program's final rule, which is now pending.

Stakeholder buy-in

US SHIP's success depends on strong buy-in from producers, states, and industry groups. Dr. Carpenter pointed to the National Pork Board, the National Pork Producers Council, and numerous state pork associations as essential partners.

"These organizations have provided excellent support for US SHIP and helped bridge the gap between regulators and producers," she said. "We owe them credit for helping build that trust and ensuring producers see the value in participation."

US SHIP certification requirements ask that enrolled farms or slaughter facilities, among other things, have a valid veterinarian-client-patient relationship maintained for eligible site types, keep electronic records for all swine movement, and maintain compliance with ASF and CSF sampling and testing requirements.

As of the end of this year, 38 states were participating in the program, with more than 12,000 swine facilities enrolled, covering nearly three-quarters of the country's pig population.

The program's cooperative approach also fits within APHIS's longstanding relationships with state animal health officials. "USDA already works closely with states on a variety of regulatory programs, so US SHIP fits into that framework naturally," she said.

Looking ahead

Standing up US SHIP required Dr. Carpenter and her colleagues to navigate complex federal regulatory processes. Logistical restrictions and requirements could easily derail a proposed rule if not handled carefully. "Maintaining awareness of regulatory requirements during rulemaking is critical. Thankfully, I've had supervisors and colleagues who are very well versed in these processes. They've helped ensure our team stays within the federal regulatory guardrails," she said.

APHIS has since hired Dr. Vienna Brown as senior coordinator for US SHIP to oversee the program's day-to-day activities. Dr. Carpenter continues to play a central role in coordinating among stakeholders and supporting the program's development behind the scenes.

Dr. Carpenter's leadership during the formative stages of US SHIP this June earned her a Samuel J. Heyman Service to America Medal for Innovative Solutions to Agricultural Challenges. Known as a "Sammie," the award honors federal employees whose achievements have had significant national impact.

Dr. Carpenter said she was "floored" by the recognition. "A lot of the time, as public servants, we don't want our work to be acknowledged in the public forum," she said. "But with US SHIP, I think the Sammie award brings really good visibility to the program, and that's something I'm excited about."

Dr. Carpenter is quick to point out that US SHIP's success is a collective achievement. "It may be my name on the award, but US SHIP has been a group effort," she said. "This program exists because of the hard work of USDA staff, state officials, and industry partners. I feel very lucky to work with such a dedicated team."

ASF is still a threat, and Dr. Carpenter acknowledges that swine producers and regulators must remain vigilant even as other disease threats capture attention. "High-path avian influenza and screwworms are on people's radar right now, but ASF has not gone away. It's critical that we continue preparing," Dr. Carpenter said.

She takes satisfaction in knowing the U.S. swine industry is better positioned today against disease threats than it was a decade ago. "I'm proud that we are doing everything we can to protect the health of our swine herd and, should a disease introduction occur, everything we can to maintain the economic viability of the pork industry," Dr. Carpenter said.

While US SHIP is focused on swine, Dr. Carpenter said she sees potential for similar programs in other livestock industries. "The NPIP framework has been extremely beneficial to the poultry industry, and I would hope that other livestock sectors, like cattle, would be able to benefit from a similar approach," she said, adding that aquaculture is already exploring certification programs, suggesting momentum is building across agriculture for cooperative, certification-based models of disease prevention and control.