In today’s Beef Buzz, senior farm and ranch broadcaster Ron Hays talked recently at CattleCon26 with Sigrid Johannes, Senior Director of Government Affairs For NCBA, about the growing concern surrounding New World screwworm and what government and industry are doing to keep it out of the United States. Johannes says that even in winter, the threat remains real. “It is absolutely still a very present threat, Ron,” she explained, noting that Mexico has now recorded more than 14,000 cases since late 2024, with roughly 70 percent occurring in cattle.
Johannes outlined how the outbreak has steadily moved north through Mexico, with recent cases appearing closer to the U.S. border. “You’re now seeing number of new cases popping in Tamaulipas… about 200 miles south of the border with Texas,” she said, adding that a case earlier in Nuevo León caused particular concern because of its proximity. Despite that spread, Johannes emphasized that the overall strategy to stop screwworm has not changed. “The things that we need to beat this thing are the same today as they were a year ago… We need more sterile flies. We need treatments, and we need effective movement controls.”
On the sterile insect front, Johannes pointed to progress that is underway, even if it can be hard to see while Mexico’s situation worsens. She highlighted a new sterile fly production plant in Chiapas expected to come online in July and improvements at the Moore Airfield facility in South Texas. “The hope is to have enough sterile flies to push the New World screwworm back through Mexico into Central America,” she said, explaining that expanded production over the next 12 to 24 months will be critical.
Johannes also said producers now have more tools available if the pest does reach the U.S. “We do have two conditionally approved treatments for this,” she told Hays. One is a topical fluralaner product, Merck’s Exzolt CA-1, and the other an injectable doramectin product, Zoetis Dectomax®-CA1. She called those approvals “two really good steps forward for producers” who are asking what they can do for prevention and response.
The biggest unresolved issue, according to Johannes, remains livestock movement controls. She said NCBA has been “deep in the weeds with APHIS, with USDA,” working on a New World screwworm playbook that balances strict disease control with continuity of business. Responding to questions about USDA’s consideration of placing sterile fly dispersal polygons in South Texas, Johannes stressed that it does not indicate a problem in the U.S. “I don’t think that anybody should read into that polygon as a sign that we have a problem in Texas, because we don’t,” she said, adding that the approach reflects a very proactive United States Department of Agriculture trying to stay ahead of a steadily advancing threat.
Coverage of CattleCon26 is powered by Farm Data Services of Stillwater, Oklahoma.
The Beef Buzz is a regular feature heard on radio stations around the region on the Radio Oklahoma Ag Network and is a regular audio feature found on this website as well. Click on the LISTEN BAR for today’s show and check out our archives for older Beef Buzz shows covering the gamut of the beef cattle industry today.
