A second case of New World screwworm (Cochliomyia hominivorax) has been confirmed in a one-month-old calf in Zavala County, Texas, USA. This finding, which occurred on June 5, 2026, is 5.6 miles from the first confirmed detection on June 3, 2026, in another calf. Both detections are within a 20-km movement control zone.
These are the first confirmed animal infestations in the US since 1966, excluding an outbreak in Florida in 2016-2017. The USDA is releasing sterile flies to eradicate the pest and has issued emergency authorizations for treatments.
The human risk is considered low, but public awareness is being maintained. Cross-border pressure from Mexico is the primary long-term risk.
