Screwworm case confirmed near US-Mexico border
USDA considers sterile fly release as outbreak spreads north
22 September 2025
1 minute read
By: 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 US-Mexico border, Reuters reported, citing the US Department of Agriculture.
"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 US cattle industry on high alert.
The outbreak has prompted the US government to keep its border mostly closed to Mexican cattle imports since May.
A human case of screwworm in the US reported in August posed no risk to the farm sector, a US Department of Agriculture official said at the time.
