Alarm as once-eradicated flesh-eating parasite found in calf in Texas

Larvae of the screwworm fly, collected from infected cows, are observed at the COPEG sterile fly production plant in Pacora, Panama, in 2025. Photograph: Enea Lebrun/Reuters View image in fullscreen Larvae of the screwworm fly, collected from infected cows, are observed at the COPEG sterile fly production plant in Pacora, Panama, in 2025. Photograph: Enea Lebrun/Reuters Alarm as once-eradicated flesh-eating parasite found in calf in Texas USDA confirms first case of New World screwworm in cattle in six decades, posing threat to livestock industry A flesh-eating parasite rarely seen in the US in six decades has been found in a calf in Texas , agriculture officials said, in an alarming development for the country’s cattle industry. The New World screwworm fly ( NWS ) was confirmed in the animal in the south of the state, about 50 miles from the Mexico border, Brooke Rollins, the agriculture secretary, said late on Wednesday. For more than a year, the US agriculture department (USDA) and officials in Texas have been warning livestock owners about the parasite’s progression across Mexico. The screwworm fly’s larvae feed on the blood of warm-blooded animals, and while the risk to humans is low, the parasite can spread quickly where large numbers of cattle and other livestock are kept together. It was eradicated from the US in the 1970s after causing tens of millions of dollars in losses, and officials fear a resurgence now at a time when food prices across the country, especially for beef, are at record highs . Maryland screwworm case has US officials bracing for return of an old foe Read more The flies pose no threat to food safety, but officials fear shortages if they take hold in cattle and poultry populations. “For months, the screwworm has advanced rapidly through Mexico in spite of the USDA’s existing gameplan,” Sid Miller, the Texas agriculture commissioner, said in a statement . “Even though billions of sterile flies have been dispersed by USDA, the screwworm has still advanced over 1,100 miles from southern Mexico to Texas, and USDA has missed an important component. Now that it appears the first screwworm has arrived in Texas, the consequences of that decision are now staring us in the face.” Rollins defended her agency in comments on Wednesday night, and insisted “there is no threat of mass infestation,” according to the Associated Press . “There is no reason to believe this incursion will result in establishment of the pest in our country,” Rollins said, adding that the Texas case was the only one so far, and the first confirmed detection in the state since 1966. In August 2025, federal health officials confirmed a case in a Maryland resident who had traveled to El Salvador, but the victim recovered and officials found no transmission of the parasite. Before that, the last outbreak was in the Florida Keys in September 2016, mostly among wild deer, and it was contained early the next year without spreading further. Female screwworm flies ta