WASHINGTON — Agriculture Secretary Brooke Rollins wrote a letter to her counterpart in Mexico over the weekend saying that the United States would cease all live animal imports in the next few days if there is not a change in policy for the spread of New World screwworm (NWS).

Rollins said the federal government would block the importation of all live cattle, bison and equine on April 30 if the Mexican government does not combat the issue.

“We are now at a critical inflection point in our shared campaign against this pest, and I am very concerned about our collaboration,” Rollins said in the letter. “The outbreak in southern Mexico continues to expand, and every day that passes without full deployment of sterile insect technique (SIT) operations represents a lost opportunity to contain this pest and prevent its spread beyond the Isthmus of Tehuantepec.”

NWS are fly larvae that infest the living tissue of warm-blooded animals, causing infection. According to the Animal and Plant Health Inspection Service (APHIS), the maggots can infest livestock and other warm-blooded animals, including people.

The primary concern involved Dynamic Aviation, a US government-contracted carrier that helps with aerial fly dispersals to combat NWS.

Rollins stated in her letter that Mexican aviation officials only allow Dynamic to fly six days a week, which she says is not enough for the NWS’ response. The contractor is also working on a 60-day permit.

In her letter, Rollins noted that Mexican customs authorities are imposing “substantial import duties” on aviation parts, dispersal equipment and sterile fly shipments.

Rollins asked that Dynamic receive a longer operational clearance, full import and duty waivers for items related to the eradication campaign and designate a high-level point of contact to work with APHIS.

Over the weekend the National Cattlemen’s Beef Association (NCBA) came out in support of Rollins actions to stop the NWS threat.

“The US spent millions of dollars to eradicate New World screwworm from our borders in the 1960s, but unfortunately we are now facing this dangerous threat again,” said Buck Wehrbein, president of the NCBA. “Screwworm is very destructive and could cost American producers millions of dollars a year if it reaches us. Americans have been investing in prevention efforts in Central America for decades, but we can’t stop this without Mexico’s participation. NCBA strongly supports Secretary Rollins holding Mexico to their commitments regarding screwworm eradication.” 

The trade association said it met with officials at the Embassy of Mexico in Washington to ask for more action on the eradication.