Mexico-U.S. Border Remains Closed to Cattle Exports Amid Screwworm Outbreak

Mexico and the United States have not yet agreed on a date to resume Mexican cattle exports to the U.S. due to an outbreak of the flesh-eating New World screwworm parasite. Mexican Agriculture Minister Julio Berdegue and U.S. Agriculture Secretary Brooke Rollins have been in communication and made progress but remain unable to set a reopening timeline. Both countries are collaborating on testing modular mobile plants in Mexico to increase production of sterile flies, which help control screwworm populations by sterilizing wild flies and reducing their numbers. A new sterile fly plant in Chiapas, Mexico, supported by a $21 million U.S. investment, is expected to produce 100 million sterile flies weekly when fully operational. Berdegue emphasized that resuming cattle exports depends on reaching adequate sterile fly production levels to ensure the parasite is controlled. The screwworm infestation, which spread from Central America into Mexico, has caused ongoing livestock sector disruptions and border restrictions since May 2025.