The New World screwworm, a flesh-eating parasite, has re-appeared in the United States after decades of eradication.

This resurgence threatens the U.S. cattle industry and could lead to severe economic losses if the parasite spreads beyond the border regions of Texas. The pest targets livestock by attacking open wounds, leading to tissue destruction and animal death.

U.S. Department of Agriculture (USDA) and animal-health officials are working with Texas ranchers to contain the outbreak. First confirmed cases in Texas were reported in August 2025 [1]. The situation has escalated this month, with two more cases of the New World screwworm confirmed in animals located far apart within the state [2].

The parasite was previously eradicated from the U.S. more than 50 years ago [3]. During that era, the pest severely impacted the cattle industry before a sterile-insect control program successfully eliminated the population [3]. Officials said the current outbreak is linked to the cross-border movement of the parasite and a lapse in that control program [4].

Economic impacts are already manifesting. Reports indicate that border closures related to the parasite have fueled a beef boom in Mexico while creating economic gloom in Texas [4]. The USDA is racing to implement containment measures to prevent a wider agricultural crisis.

Experts said that while the public should remain vigilant, there is no need to panic [5]. However, the geographical distance between the two most recent cases suggests the parasite may be more widespread than initially feared [2].

“The New World screwworm, a flesh-eating parasite, has re-appeared in the United States after decades of eradication.”

The return of the New World screwworm represents a significant failure in biological containment and a potential shift in regional trade. Because the parasite can devastate livestock populations, the U.S. may be forced to maintain strict border controls and animal movement restrictions, which could permanently alter the economic balance of the beef trade between the U.S. and Mexico.