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

Although not a risk to human health, the virus spreads easily between pigs and can be hard to detect in time to prevent transmission. 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 percent of predicted cases, with local and vehicle-driven spread contributing to 14.6 and 14.4 percent 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 conclude, 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 N.C. 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. U.S. Agriculture Department officials warn that the arrival of African swine fever could force a halt in pork product exports, catastrophic price drops and the need to cull herds. They urge anyone with pigs to be on the alert for symptoms such as high fevers, weakness, blotchy skin rashes or coughing.