ALEXANDRIA, VA (RFD NEWS) — Efforts to contain and ultimately eradicate New World screwworm continue to intensify as expanded detections in Texas prompt a broader federal response and renewed coordination across the livestock industry.
Dr. Stephanie Mercier with the Farm Journal Foundation joined us on Thursday’s Market Day Report to discuss USDA efforts to eradicate the pest in the United States.
In her interview with RFD News, Dr. Mercier explained that sterile fly dispersal remains the primary and most effective tool currently being used to stop the spread of the livestock parasite. She also emphasized the importance of producer vigilance, noting that New World screwworm can affect a range of warm-blooded animals beyond cattle, including dogs, goats, and horses.
“I think the dispersal is the major tool in the toolbox right now,” she said. “The other one is that it’s important that cattle ranchers and other livestock owners are vigilant about checking their animals on a regular basis to make sure that there’s not an infestation of these New World screwworm larvae affecting their animals."We need to keep in mind it’s not just cattle that these flies are attacking. It’s really any warm-blooded animal. Two of the seven cases that have been detected were not cattle.”
Dr. Mercier also discussed other parts of USDA’s ongoing response strategy, including its “Grand Challenge” initiative, which gathered more than 200 private-sector proposals aimed at stopping the spread of the pest.
“I’ll be interested to see what comes out of this Grand Challenge,” Dr. Mercier told RFD News. “But my suspicion is a lot of what’s going to be funded through that is going to be a long-term effort, not a short-term response.”
She also reflected on recent trade and livestock movement restrictions imposed by several states and Canada in response to detections in Texas. Mercier described those actions as precautionary measures that are unlikely to significantly affect the spread of disease but could have economic impacts on affected producers.
“I think it’s an expected move,” Mercier explained. “It’s not necessarily going to have much effect because I don’t think a lot of Texas animals move across the border on a regular basis. I think it’s a precautionary move that probably won’t have a major impact on the spread of this pest, but it could have an impact on the profitability of Texas cattle operations.
Mercier also addressed concerns from livestock producers about reporting suspected cases, noting that some may worry about potential quarantines or movement restrictions.
“I can understand their concern that if they find what they think might be a case and report it, that could end up with their operations being quarantined and movement of their cattle restricted, which for some producers may be a disincentive for reporting it,” Dr. Mercier said. “I still think those two things I mentioned at the top—the dispersal of sterile flies and the monitoring by farmers—are the two most important things we’ll have to rely on for the next several months.”
She stressed that strong biosecurity depends on coordinated action across neighboring operations and that early reporting is essential to preventing further spread.
“We all need to work together on this,” she continued. “But it’s very important to keep in mind that good biosecurity measures depend not just on what you’re doing on your farm, but what your neighbors are doing as well. And if one farmer, or a handful of farmers, decides not to abide by their request, then that could allow this to go on even longer than it otherwise would.”
She explained that current sterile fly production capacity is significantly lower than the levels used during past eradication efforts, such as the 1960s outbreak response, thereby limiting the speed of containment. She warned that strict adherence to biosecurity at the operation level is absolutely critical at this stage. She also reiterated that if producers believe they come across the pest in their herds or other animals to report to local agriculture officials immediately.
“They need to report it — whether it’s to their veterinarian or to the local extension office or relevant state agencies in Texas or whatever state — let those authorities determine whether or not it’s an actual case,” she cautioned. “Farmers should not rely on their own judgment. They should pass on the suspicion that a case may exist and let someone else confirm it.”
Looking ahead, Mercier said much of the innovation emerging from USDA’s Grand Challenge is likely to focus on longer-term solutions, while near-term control will continue to rely heavily on sterile fly dispersal and producer monitoring.
LEARN MORE: www.screwworm.gov
