SHIC Work on Asian ASF Study Begins with Trip to Vietnam

October 9, 2019 — Paul Sundberg

In August, it was announced the Swine Health Information Center (SHIC) received a grant from the USDA Foreign Agricultural Service, with active support from the National Pork Producers Council (NPPC), to start a dialogue between the US and Asia, sharing veterinary knowledge and ways to prevent African swine fever (ASF) from further spreading. In September, SHIC Executive Director Dr. Paul Sundberg traveled to Vietnam as this process was launched. In this first phase, as key stakeholders were identified, collaboration and tours of ASF-affected farms in Vietnam gave Dr. Sundberg and strategic partners in the process a first-hand look at the disease's impact. Dr. Sundberg notes it will be easy to mistake an ASF outbreak for porcine reproductive and respiratory syndrome (PRRS), salmonella septicemia, or any other herd-level disease. "Veterinarians need to communicate to producers that they can't assume that what they see is what they've had in their barns before," he explained. "Producers need to get a professional diagnosis every time they have a morbidity or mortality event on the farm, no matter if it is individual or multiple animals."

During this initial visit to Vietnam, Dr. Sundberg and colleagues in the process met with staff from laboratories as well as producer companies to set up the infrastructure for implementation of the work outlined in the grant. A USDA/Vietnamese Department of Animal Health (DAH) meeting of "first responders" was an opportunity to listen to the government agencies talk about policies and communications.

On their visit to an ASF-affected farrow-to-finish farm, they noted mortality had been steady with one to several pigs dying every day. Staff on the farm did not describe a dramatic initial die-off. Pigs continue to get recruited into the disease and predictably die five to 10 days after they initially notice off-feed or fever. At the finishing farm toured, pigs ranged from 20 to 40 kg (44 to 88 pounds) bodyweight and were almost uniformly severely affected by ASF. Nearly all were extremely reluctant to rise and move, and when they did, generally just relocated and laid back down. By touch, most all pigs had easily detectable fever. There was some evidence of respiratory disease, but not as dramatic as on the first farm visited. Diarrhea was common in all pens; digested blood was apparent in the feces. Frank blood was easy to identify on the backs of pigs, walls of pens, and floors of pens but it was not obvious what the source of the blood was.

Dr. Sundberg emphasizes that the clinical picture of ASF is severe, however, could easily be assumed to be something else, for a few days or a week, if not investigated immediately. "I just heard the description that ASF is like lava from a volcano - it doesn't move fast but it just keeps moving and it burns everything in its way," he notes.

In the next steps of the project following this initial visit, ASF-related field projects will be implemented, including those helping to inform the U.S. pork industry about effective ASF preparedness and response. Key to the success of the overall mission will be these field projects in Vietnam, including analysis of pathways of entry onto the farms, collection and analysis of swine oral fluids, biocontainment of the virus after entry to the farms and cleaning, disinfection and repopulation trials, which will provide valuable data for all participants and US pork producers. In an additional phase of the grant-funded process, the strategic partners will train the Vietnamese veterinary workforce on ASF prevention and control, helping to build local veterinary capacity.

SHIC, NPPC, AASV and the National Pork Board are working closely with the USDA to first prevent ASF from entering the US swine herd but also to be prepared to respond should an outbreak occur. The industry is actively identifying and prioritizing critical research needs and working in collaboration with state and federal animal health officials to make sure that, at a national level, all appropriate biosecurity measures are being implemented. Find ASF-related resources and information on the SHIC website.

Funded by America's pork producers to protect and enhance the health of the US swine herd, the Swine Health Information Center focuses its efforts on prevention, preparedness, and response. As a conduit of information and research, SHIC encourages sharing of its publications and research for the benefit of swine health. Forward, reprint, and quote SHIC material freely. For more information, visit http://www.swinehealth.org or contact Dr. Paul Sundberg at psundberg@swinehealth.org.

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Paul Sundberg, Executive Director, Swine Health Information Center