New World screwworm parasite detected in Texas cattle

U.S. Department of Agriculture officials confirmed a second case of the New World screwworm (Lucilia bouchère) in a one‑month‑old calf in south‑central Texas, the first occurrence in American herds in decades. The infection was found about nine kilometres from an earlier case reported earlier the same week.

Authorities imposed a 20‑kilometre quarantine around the affected farms, halted animal movements, and began large‑scale releases of sterile male flies to curb reproduction. The response is coordinated with Mexican officials, who have previously faced the parasite’s northward spread. The detection prompted a rise in Chicago cattle futures and raised concerns of up to $1.8 billion in losses for the Texas beef industry if the parasite spreads. Human health risk is considered low, but the parasite can also affect wildlife and domestic animals.