Dangerous Parasite Returns to U.S. After 60 Years

The U.S. Department of Agriculture confirmed New World screwworm in two Texas cattle in early June 2026—the first U.S. cases since 1966. The parasite's larvae feed on living tissue and multiply rapidly. Its reappearance suggests a breach in the containment barrier that has kept it south of Panama for decades, raising urgent questions about regional disease control.