The U.S. Department of Agriculture has confirmed a second case of the flesh-eating New World screwworm in Texas, raising concerns among livestock producers and animal health officials.

According to the department, the new case was detected in a one-month-old calf located about nine kilometers from the site where the first case was identified earlier this week.

Federal and state authorities are racing to contain the parasite after the first infection found on a U.S. farm in decades triggered fears of a wider outbreak.

The screwworm consists of larvae from a parasitic fly whose females lay eggs in open wounds or mucous membranes of warm-blooded animals.

Once the eggs hatch, hundreds of larvae feed on living tissue using sharp mouthparts, causing severe injuries and potentially killing the animal if left untreated.

The discovery of the two cases in Texas represents a setback for the U.S. livestock industry, which has been closely monitoring the northward spread of the New World screwworm through Mexico over the past year.