A flesh-eating screwworm has been confirmed in the United States for the first time in decades. On Wednesday (June 3), the U.S. Department of Agriculture (USDA) announced that a screwworm was detected in a three-week-old calf in Zavala County, Texas. This marks the first breach of the US-Mexico border by the parasite, which was eradicated in the U.S. about 60 years ago.

The screwworm poses a serious threat to livestock, as its larvae feed on the living tissue of warm-blooded animals. The USDA and the Texas Animal Health Commission have responded by setting up a unified Incident Command Team and implementing a 20-kilometer quarantine zone around the detection site. They are also releasing sterile flies to combat the infestation, a method that proved successful in eradicating the pest in the past.

According to Ars Technica, the USDA is dispersing 100 million sterile insects per week in Mexico and along the US-Mexico border to prevent the flies from advancing further. Agriculture Secretary Brooke Rollins emphasized the seriousness of the threat but reassured that the USDA is taking swift action to contain it.

As reported by KGNS, authorities are urging ranchers and pet owners to monitor animals closely for unusual wounds and to seek help immediately if they suspect an infection. The USDA has also suspended imports of live cattle, horses, and bison from Mexico to slow the parasite's advance.

Hoosier Ag Today reports that the re-emergence of the screwworm has alarmed the livestock industry, with officials working tirelessly to prevent the pest from establishing itself in the country. The USDA assures that the nation's food supply remains safe, as the parasite does not infest meat products.

The coming weeks will determine whether this detection is an isolated incident or the start of a broader outbreak. For now, federal and state officials are racing to contain the parasite using strategies that successfully eliminated it from the U.S. more than half a century ago.