The United States and Mexico have reached an agreement to manage the spread of the New World screwworm, a dangerous livestock pest that threatens both animal health and trade.
Talks reportedly moved forward after U.S. Agriculture Secretary Brooke Rollins warned that Mexican cattle imports could be restricted if action wasn’t taken. The screwworm, a parasitic fly, lays eggs that hatch into maggots which burrow into the flesh of living animals. The infestation can be fatal if not treated quickly. While rare, screwworms can also infect humans.
Mexican President Claudia Sheinbaum said her country has been working to contain the outbreak and strengthen its prevention systems. Under the Biden Administration, the U.S. banned Mexican cattle imports from late November 2024 through February 2025, when the Trump administration decided to again allow Mexican cattle imports. The screwworm was eradicated in the U.S. in 1966, and keeping it out remains a top priority.
Each year, the U.S. imports over one million cattle from Mexico. Any long-term disruption could further tighten American cattle supplies, which are already at historic lows.