New World Screwworm Detected Just 70 Miles from U.S. Border

Less than 70 miles stands between the latest New World screwworm (NWS) detection and the U.S.-Mexico border, according to a statement by the USDA late Sunday, Sept. 21.

“Hours ago, Mexico’s National Service of Agro-Alimentary Health, Safety, and Quality confirmed a new case of NWS in Sabinas Hidalgo, located in the state of Nuevo León,” the statement read. 

This is the farthest north NWS has been detected since the beginning of the outbreak. Before this detection, the northernmost case was reported in July from Veracruz — about 370 miles farther south. 

The detection occurred in a high-traffic area. “Sabinas Hidalgo is located near the major highway from Monterrey, Nuevo Leon, to Laredo, Texas, which is one of the most heavily trafficked commercial thoroughfares in the world,” the USDA said.

Based on preliminary reports, the diseased animal had been moved to Nuevo León from a region in southern Mexico that had known active NWS cases.

Ag Secretary Brooke Rollins shared on X that “it was one case detected on an 8 month old calf that was part of a 100 head herd transported from the south.”

“But we are taking no chances,” she said.

Rollins said in the USDA’s statement that protecting the nation from NWS is a “top priority of the Trump Administration.”

“This is a national security priority. We have given Mexico every opportunity and every resource necessary to counter NWS since announcing the NWS Bold Plan in June 2025. Nevertheless, American ranchers and families should know that we will not rely on Mexico to defend our industry, our food supply, or our way of life,” Rollins said. “We are firmly executing our five-pronged plan and will take decisive action to protect our borders, even in the absence of cooperation. Furthermore, we will pursue aggressive measures against anyone who harms American livestock.”

U.S. ports remain closed to imports of cattle, bison, and horses from Mexico.