The U.S. Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS) has confirmed the detection of New World screwworm (NWS) in a bovine in Zavala County, Texas, marking a significant development in ongoing efforts to prevent the pest’s reestablishment in the United States. The affected animal was a three-week-old calf in which NWS larvae were identified in the umbilical area. According to USDA, no additional detections have been reported to date. NWS is a parasitic fly whose larvae feed on living tissue, posing a serious threat to livestock, companion animals, wildlife, and, in rare cases, humans and birds. Infestations can cause severe tissue damage, animal welfare concerns, and substantial economic losses for producers. Federal and state officials have initiated a coordinated response under the New World Screwworm Response Playbook. Measures include establishing a 20-kilometer infested zone around the detection site, implementing quarantines and movement controls, increasing surveillance and trapping activities, and deploying response personnel through a unified incident command structure with the Texas Animal Health Commission. USDA is also reportedly accelerating sterile fly release efforts by deploying ground release chambers in the affected area, supplementing approximately 4 million sterile flies already being released aerially each week. Additional response activities include wildlife surveillance, local outreach, and preparation of treatment, equipment, and logistical resources through the National Veterinary Stockpile.
