Mexico confirms case of New World screwworm in northern state, USDA says
| 1 min read
By Reuters
Carlos Mahr, cattle producer and President of the Chiapas Livestock Union Spray disinfectant on one of his cows as the Mexican government and ranchers struggle to control the spread of the flesh-eating screwworm, in Tuxtla Gutierrez, Chiapas state, Mexico July 3, 2025. Photo: Reuters/Daniel Becerril
Mexico’s National Service of Agro-Alimentary Health, Safety, and Quality on Sunday confirmed a new case of New World screwworm in Sabinas Hidalgo, Nuevo Leon, less than 70 miles (113 km) from the U.S.-Mexico border, the U.S. Department of Agriculture said.
Why it matters: The closure of the U.S. border to Mexican cattle due to screwworm fears has constricted already tight cattle supplies, pushing Chicago cattle futures to record highs.
“USDA is analyzing all new information related to the recent case in Nuevo Leon and will pursue all options to release sterile flies in this region as necessary,” USDA said.
A spokesperson for Mexico’s agriculture ministry did not immediately respond to a request for comment.
The flesh-eating screwworm parasite has moved northward through Central America and southern Mexico, putting the U.S. cattle industry on high alert.
The outbreak has prompted the U.S. government to keep its border mostly closed to Mexican cattle imports since May.
A human case of screwworm in the U.S. reported in August posed no risk to the farm sector, a U.S. Department of Agriculture official said at the time.
—Reporting by Anmol Choubey; additional reporting by Cassandra Garrison in Mexico City.
