July 3, 2023

Up to 79% of ASF can be stopped if disease strikes southeastern US, research found

Recent research published in the Preventive Veterinary Medicine journal maps what could happen if the highly contagious African swine fever (ASF) swept across the United States and its potentially devastating consequences for pigs and farms.

In particular, scientists explored how the virus might be spread and managed, in the southeastern US. They concluded that quick action could prevent up to 79% of virus spread in the region — but that the disease could devastate livestock and farms nonetheless.

The scientists used a tool called PigSpread to model how an outbreak might play out. Developed by North Carolina State University veterinary researchers, the programme allows researchers to estimate how effective various interventions might be.

Using the PigSpread model, the researchers looked at six potential transmission routes, including the virus spreading from pig to pig via swine movements between farms, vehicle movements and local spread. They found that between-farm movements contributed to 71.1% of predicted cases, with local and vehicle-driven spread contributing to 14.6% and 14.4% of cases, respectively.

Overall, farmers and officials would need to respond with a combination of quarantine, culling herds, contact tracing, surveillance and other measures. Even then, the researchers concluded, a single case could lead to the slaughter of 495,619 animals over just 140 days.

"While these results are promising, they are still a bit optimistic," said Gustavo Machado, assistant professor of population health and pathobiology at NC State and one of the paper's co-authors, in a news release.

Even the best-case scenario would still have a deep impact on the pork industry. USDA officials warn that the arrival of ASF could force a halt in pork product exports, catastrophic price drops and the need to cull herds.

- The Washington Post