WASHINGTON (DTN) -- USDA officials are linking New World screwworm (NWS) cases to wild animals, though USDA's confirmed detections have not reported any cases so far in wildlife or the department's fly-trap detections.

Agriculture Secretary Brooke Rollins held a news conference on Monday to highlight the Trump administration's efforts to curb the spread of New World screwworm from wild animals to livestock as cases grew to 12.

USDA's Animal and Plant Health Inspection Service (APHIS) noted 10 cases in cattle, goats and one in sheep have been confirmed in Texas and one case in a dog in New Mexico.

Texas Public Radio said, "The latest Texas case was identified in a sheep in Sutton County, about 135 miles northwest of San Antonio. The detection adds to growing concerns that the parasite is spreading beyond South Texas and into other parts of the state."

Reuters reported the closure of the U.S. border to Mexican cattle imports has fueled gloom in the Texas feedlot industry while Mexico is keeping the cattle longer and processing them into meat that is exported to the United States.

In her office on Monday, Rollins told Washington and Texas-based reporters that USDA officials are increasingly worried that wild animals could spread screwworm and that they are taking steps to stop the parasitic fly from spreading from wildlife to livestock.

"Screwworm is challenging, it is a parasitic fly. It goes where it wants to go," Agriculture Under Secretary for Marketing and Regulatory Programs Dudley Hoskins, who oversees APHIS, said at the news conference.

Rollins said that USDA and Texas state government agencies are surveilling wild animals and monitoring them. As part of its "grand challenge" to solve the screwworm problem, USDA on Tuesday will announce a group of 40 finalists working on efforts to identify where the livestock are located, using dogs, drones and remote sensing to detect them and artificial intelligence and machine learning to make decisions.

Sean Conley, the Homeland Security Department acting chief medical officer, said that DHS is concerned about the movements of wildlife and livestock in the vast stretches of Texas, Arizona and New Mexico between the ports that have been closed.

But Conley noted that DHS has nearly 600 agricultural specialists who work around the border and said they have been involved in the fight against the screwworm for the past year.

Jason Suckow, director of USDA's National Wildlife Research Center said that USDA has conducted more than 20,000 inspections in border states -- including roadkill, because wounds can be a vector for the flies to lay their eggs -- but that they have found no cases of screwworms in wild animals in the United States.

Suckow said he has been working with Mexican officials since last summer and that a "handful" of cases in Mexican wildlife have been reported.

Mexico has confirmed cases in white-tailed deer and suspected cases in javelina, mountain lions, water buffalo, and tapir, Suckow said.

In the 1950s and '60s, the two most common species to be infected with screwworm were white-tailed deer and rabbits, but "the landscape in Texas is different today," Suckow said. "There are more mammals that exist in Texas now," he added, noting the presence of captive breeding programs for threatened species as well as feral swine.

Alan Cain, the Texas Parks and Wildlife Department's Wildlife Division director, said that there are concerns about screwworm spreading to white-tailed deer because hunting is a popular and economically important industry in Texas.

Asked about whether the supply of sterile male flies to mate with fertile female flies will be sufficient to control the screwworm, Rollins said that the supply will be plentiful. She noted that a USA delegation including John Bellinger, the new senior adviser for New World screwworm preparedness, were traveling today to Panama where the sterile fly production facility is located.

Rollins noted that when she visited LaPryor, Texas, she saw the calf that was screwworm case No. 1.

"He is doing beautifully," Rollins said. "You can't even see the wound." His recovery, Rollins said, sends "an important message: if an animal gets screwworm, it is not the end of the animal."

Rollins said she will travel to Corpus Christi, Texas, on Friday for an event involving drones.

The Food and Drug Administration last week issued an Emergency Use Authorization (EUA) for generic nitenpyram tablets for the treatment of New World screwworm infestations (myiasis) in dogs, puppies, cats, and kittens that weigh at least two pounds and are at least four weeks old. This is the first generic animal drug authorized for use against NWS, FDA said.

"The U.S. government is maintaining an aggressive approach to stop the spread and eradicate this pest," Health and Human Services Secretary Robert F. Kennedy Jr. said in a news release.

"When I signed the initial emergency declaration back in August 2025, we established a proactive defense. Today's authorization is the latest tactical tool in that ongoing containment strategy -- providing an affordable, fast-acting treatment for dogs and cats in affected areas."

"The FDA has spent nearly a year fast-tracking reviews and readying for the arrival of New World screwworm in the U.S.," said FDA Commissioner Kyle Diamantas.

"As of today, under the Trump administration's decisive leadership, the FDA has issued 10 EUAs and three conditional approvals for drugs to combat this threat, and this count will continue to grow as we receive more animal drug submissions and unleash American regulatory speed."

The American Farm Bureau Federation's Market Intel service published a detailed history of the screwworm and broke the cases into "detection zones" in Texas and New Mexico.

"While the cases remain limited in number and do not threaten the safety of the U.S. food supply, they serve as a reminder that eradication is not a one-time achievement but an ongoing process that requires vigilance, resources and cooperation," Farm Bureau economists Bernt Nelson and Daniel Munch wrote.

The National Pork Producers Council today told its members they need to "prepare for New World screwworm and keep an extra eye on biosecurity."

In its weekly "Capital Update," NPPC said it has been "working with USDA, FDA, state animal health officials, the American Association of Swine Veterinarians, the Swine Health Information Center, and the National Pork Board to understand what a response would look like for the swine industry and to address concerns and gaps. NWS has the potential to impact swine welfare and business continuity for producers throughout the U.S."

For more DTN coverage of the New World screwworm threat and the response by the government and livestock industry, visit DTN's Spotlight on New World screwworm page at https://www.dtnpf.com/….

Jerry Hagstrom can be reached at jhagstrom@nationaljournal.com

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