USDA Shuts Down U.S. Southern Border Ports as New World Screwworm Moves North

Mexico's National Service of Agro-Alimentary Health, Safety, and Quality reported a new case of New World Screwworm (NWS) in Ixhuatlan de Madero, Veracruz in Mexico. This location is approximately 160 miles northward of the current sterile fly dispersal grid on the eastern side of the country and 370 miles south of the U.S./Mexico border.

This new northward detection comes approximately two months after northern detections were reported in Oaxaca and Veracruz, less than 700 miles away from the U.S. border, which triggered the closure of our ports to Mexican cattle, bison, and horses.

While USDA announced a risk-based phased port re-opening strategy for cattle, bison, and equine from Mexico beginning as early as July 7, 2025, this newly reported NWS case raises significant concern about the previously reported information shared by Mexican officials. And, it severely compromises the outlined port reopening schedule of five ports from July 7-September 15. Therefore, in order to protect American livestock and our nation's food supply, USDA Secretary Rollins has ordered the closure of livestock trade through southern ports of entry effective immediately.

"The United States has promised to be vigilant -- and after detecting this new NWS case, we are pausing the planned port reopening’s to further quarantine and target this deadly pest in Mexico. We must see additional progress combatting NWS in Veracruz and other nearby Mexican states in order to reopen livestock ports along the Southern border," said Secretary Rollins. "Thanks to the aggressive monitoring by USDA staff in the U.S. and in Mexico, we have been able to take quick and decisive action to respond to the spread of this deadly pest."

To ensure the protection of U.S. livestock herds, USDA is holding Mexico accountable by ensuring proactive measures are being taken to maintain an NWS-free barrier. This is maintained with stringent animal movement controls, surveillance, trapping, and following the proven science to push the NWS barrier south in phases as quickly as possible.

In June, USDA also announced the groundbreaking of a sterile fly dispersal facility in South Texas. This facility will provide a critical contingency capability to disperse sterile flies should an NWS detection be made in the southern United States. Simultaneously, USDA is moving forward with the design process to build a domestic sterile fly production facility to ensure it has the resources to push NWS back to the Darien Gap. USDA is working on these efforts in lockstep with border states - Arizona, New Mexico, and Texas - as it will take a coordinated approach with federal, state, and local partners to keep this pest at bay and out of the U.S.

USDA will continue to have personnel perform site visits throughout Mexico to ensure the Mexican government has adequate protocols and surveillance in place to combat this pest effectively and efficiently.

EDITOR’S TAKE:

The NWS could provide a serious threat to our cattle herds if allowed to migrate into the U.S. from Mexico. It can be deadly and very costly to cattle producers and consumers. Estimates of $100 billion in potential damages (if found in cattle herds) have been floated recently. Also, with already reduced supplies of beef, if you add negative impacts from NWS, consumers could be priced out of beef as a meat choice.

It is incumbent upon all of us to support the efforts of USDA to keep this horrific pest from reaching our border and impacting our cattle. This is serious business and any input you could provide to your federal elected officials to encourage them to maintain funding for the effort to combat NWS would be greatly appreciated by cattle producers in your area, as well as across the nation.