Texas establishes new screwworm zone in Terrell County

Texas has established a new infested zone in Terrell County following the confirmation of New World screwworm in sheep. Under the direction of the Texas Animal Health Commission, warm-blooded animals are now prohibited from leaving the designated area without inspection by a certified official. This detection is part of a larger outbreak that the USDA has recorded at 45 cumulative detections in the United States, though only five cases remain active, all located within Texas.

In response to the threat, the FDA has granted emergency use authorization for CLiK Extra, a topical wound spray sponsored by Elanco. The product is designed to prevent infestations in sheep, cattle, goats, swine, and certain wildlife species by being applied to or around wounds.

Unlike most fly larvae that feed on dead tissue, the New World screwworm larvae burrow into and feed on living tissue. This behavior can cause wounds to enlarge rapidly, potentially leading to animal death within one to two weeks if left untreated. The parasite was previously eradicated in the U.S. decades ago, but recent detections have prompted these new regulatory and preventative measures.