The U.S. Department of Agriculture confirmed a case of the New World screwworm parasite in a Texas calf on Thursday.

The discovery threatens a national cattle herd already facing significant instability. Because the parasite is flesh-eating and highly invasive, its re-emergence could cause widespread livestock losses and disrupt the food supply.

Agriculture Secretary Brooke Rollins said, "The case of New World screwworm was confirmed in a three‑week‑old calf [2] in La Pryor, Texas, near the U.S.–Mexico border."

The parasite likely crossed the border from Mexico, where the species remains endemic. This marks the first detection of the parasite in the U.S. in several decades, though reports vary on the exact timeframe. One source cited a gap of nearly 10 years [1], while another noted it has been approximately 60 years [2] since the last case.

USDA officials are now focused on containment to prevent the parasite from spreading to other herds. Rollins said, "We are working closely with state and local partners to contain the outbreak and protect our livestock industry [1]."

The timing of the outbreak is particularly critical for the agricultural sector. A USDA spokesperson said, "The U.S. cattle herd is at its lowest level in 75 years [1], making any new disease threat especially concerning."

Officials have not yet released the full details of the quarantine measures in La Pryor, but the focus remains on preventing the parasite from establishing a permanent foothold in the region.

“The U.S. cattle herd is at its lowest level in 75 years”

The re-emergence of the New World screwworm creates a compounding crisis for U.S. ranchers. With the cattle population already at a 75-year low, the industry has less biological redundancy to absorb the impact of a parasitic outbreak. If containment fails, the resulting livestock deaths could drive up meat prices and further destabilize the domestic beef supply chain.