Southern Border Ports Shut Down Due to Northward Spread of NWS

The flesh-eating livestock pest New World screwworm (NWS) has moved closer to the United States border with Mexico and prompted the United States Department of Agriculture (USDA) to halt imports of Mexican cattle, bison, and equines into this country. 

The USDA had previously announced a risk-based phase port re-opening strategy for cattle, bison, and equines from Mexico beginning as early as July 7. This new northward detection comes about two months after the ports were closed in early May and the newly reported NWS case raises concern and compromises the outlined port reopening schedule of five ports from July 7–Sept. 15. 

“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,” U.S. Secretary of Agriculture Brooke L. Rollins said in a release. “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.”

New World Screwworm can cause devasting injury when the fly lays eggs on a wound for exposed tissue and the hatched fly larvae (maggots) burrow into the flesh of a living animal. They can cause serious, often deadly injury and can infest livestock, pets, wildlife, occasionally birds, and in rare cases, people. 

In June, the USDA announced its plan to combat New World Screwworm by increasing eradication efforts in Mexico. USDA also announced the groundbreaking of a sterile fly dispersal facility in Southern 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. 

In addition, a new NWS screwworm information page was launched to provide tips on what to look for, how to prevent this disease, and how it is treated. The webpage also displays the current status of NWS in Mexico and Central America. 

To read more about New World Screwworm go to the EDCC NWS webpage HERE.