Flesh-eating screwworm detected in Texas for first time in decades Federal and state officials confirmed the detection of the New World screwworm in a calf in Zavala County, Texas. This marks the first confirmed case in U.S. livestock in decades. The screwworm is a parasitic fly whose larvae burrow into the living tissue of warm-blooded animals.

• New World screwworm detected in a 3-week-old calf.
• Location of detection: Zavala County, Texas.
• This is the first confirmed case in U.S. livestock in decades.
• The screwworm is a parasitic fly whose larvae infest warm-blooded animals.
• Detection confirmed by federal and state officials on Wednesday.