On Sunday, U.S. Secretary of Agriculture Brooke Rollins announced the immediate suspension of live cattle, horse, and bison imports through U.S. ports of entry along the southern border due to the continued and rapid northward spread of New World Screwworm (NWS) in Mexico. NWS has been recently detected in remote farms with minimal cattle movement as far north as Oaxaca and Veracruz, about 700 miles away from the U.S. border.
The United States and Mexico continue efforts to interdict and eradicate NWS in Mexico. However, despite these efforts and the economic impact on both countries due to this action, the agency says that NWS continues to migrate northward and additional action must be taken to slow the northern progression of this deadly parasitic fly.
According to a statement released on Sunday afternoon, the USDA Animal Plant Health Inspection Service (APHIS) and Customs and Border Protection (CBP) say they will restrict the importation of live animal commodities originating from, or transiting Mexico effective immediately. This import suspension will continue on a month-by-month basis, until a significant window of containment is achieved.
USDA says it will continue constant collaboration with Mexico, including a review of latest data and metrics in two weeks.
“Our teams have been in daily communication discussing how we can build on the good work that has been accomplished to improve our strategy toward eradication. Any livestock currently in holding for entry into the United States will be processed normally, this includes an APHIS port Veterinary Medical Officer inspection exam and treatment to ensure they are not carrying NWS,” said USDA in a statement.
Rollins released the following statement on Sunday afternoon:
“The United States has ordered the suspension of livestock imports through ports of entry along our southern border after the continued spread of the New World Screwworm in Mexico. Secretary Berdegué and I have worked closely on the NWS response; however, it is my duty to take all steps within my control to protect the livestock industry in the United States from this devastating pest. The protection of our animals and safety of our nation’s food supply is a national security issue of the utmost importance. Once we see increased surveillance and eradication efforts, and the positive results of those actions, we remain committed to opening the border for livestock trade. This is not about politics or punishment of Mexico, rather it is about food and animal safety.”
USDA previously and successfully led the eradication of NWS in the U.S. and Mexico nearly 60 years ago. However, the agency says these recent detections in Mexico show that this dangerous pest is back and remains a serious threat to the health of our animals, our food supply, and the security of our country.
Following Rollins’ announcement, Colin Woodall, CEO of the National Cattlemen’s Beef Association (NCBA), released the following statement:
“For months, NCBA and affiliated state cattle industry associations have been working with USDA officials urging their counterparts in Central America to take stronger action to stop the spread of New World screwworm. In the 1960s, America’s cattle and livestock producers spent years and millions of dollars to eradicate New World screwworm from the United States.
“USDA’s border closure was entirely avoidable. U.S. government officials, NCBA and leaders from affiliated state cattle industry associations have been sounding the alarm for months. Unfortunately, the Mexican government created unnecessary bureaucratic hurdles which rendered prevention efforts ineffective and allowed screwworm cases to spread unchecked beyond control points in southern Mexico. The Mexican government’s failure to knock down senseless obstacles has left America with no alternative but a closure of the U.S. border until the outbreak is verifiably stopped and the flies pushed back south of Panama’s Darien Gap.”
BACKGROUND:
- The first case of NWS in Mexico was reported to the U.S. in November 2024. When NWS fly larvae (maggots) burrow into the flesh of a living animal, they cause serious, often deadly damage to the animal. NWS can infest livestock, pets, wildlife, occasionally birds, and in rare cases, people.
- In November 2024, after a positive detection of NWS in southern Mexico, USDA shut down the border for live animal trade.
- In February 2025, USDA resumed imports after APHIS and Mexico agreed to and implemented a comprehensive pre-clearance inspection and treatment protocol to ensure safe movement and steps to mitigate the threat of NWS.
- Over the last two years, screwworm has spread north throughout Panama and into Costa Rica, Nicaragua, Honduras, Guatemala, El Salvador, Belize, and now Mexico.
APHIS is releasing sterile flies through aerial and ground release at strategic locations, focusing on Southern Mexico and other areas throughout Central America. A complete list of regions APHIS recognizes as affected by NWS as well as more detailed information on trade restrictions can be found on the USDA APHIS Animal Health Status of Regions website.
Source: USDA, National Cattlemen’s Beef Association.
