Officials warn of New World screwworm threat; call for surveillance and international coordination

The House Agriculture Subcommittee on Livestock, Dairy, and Poultry heard testimony that the reappearance and spread of the New World screwworm in Mexico presents a major economic threat to U.S. cattle and dairy producers and requires coordinated surveillance and international cooperation. Chairman Mann cited USDA cost estimates discussed at the hearing, saying a contemporary outbreak in Texas alone could cost producers $732 million per year and that historic estimates put annual producer costs as high as $4.3 billion with total economic losses exceeding $10 billion. He asked lab directors how NAHLN laboratories would be involved in detection and response. Dr. Jamie Riedelik said many NAHLN labs, being university and state departmental labs, have parasitologists and pathologists trained to recognize screwworm and that the network discusses the pest on weekly calls and provides training. She said routine caseloads in diagnostic labs provide passive surveillance because samples and carcasses submitted for other reasons can reveal new threats. Members and witnesses identified USDA and state animal health agencies (for example, the Texas Animal Health Commission) as the focal points for coordination and response. Dr. Hensley and other witnesses described ongoing weekly calls that include state agencies, veterinary services staff and extension services to track the pest’s movement and coordinate surveillance priorities. Panelists discussed international efforts cited in testimony: funding and projects in Mexico to retrofit rearing facilities and produce sterile flies, and plans to establish rearing capacity in Mission (Texas) and Panama; witnesses said such efforts take time and that surveillance at the border and within high‑risk states must be sustained. Representative Van Orden asked who is leading the tracking effort; witnesses and members repeatedly pointed to USDA and the respective state animal health agencies as the lead coordinators, with NAHLN providing diagnostic recognition and testing support. Witnesses encouraged continued federal support for surveillance, lab capacity and cross‑border coordination to reduce the likelihood of a damaging outbreak.