Blab News
New World Screwworm Confirmed in Texas and New Mexico, Authorities Initiate Investigations
A silent pest has returned to the American Southwest—on June 7, the Texas Animal Health Commission (TAHC) confirmed the presence of the New World screwworm (Cochliomyia hominivorax) in Andrews County, Texas. The finding follows a second case in La Salle County, involving a calf with an umbilical lesion, and a dog in Andrews County that was later traced to a residence in Lea County, New Mexico.
The dog case marks the first confirmed screwworm detection in New Mexico. Because the animal’s recent travel and exposure history remain unknown, the United States Department of Agriculture (USDA) and state partners are inspecting additional animals at the dog’s home. USDA officials described the situation as “isolated” while emphasizing that the agency is conducting a thorough investigation.
The New World screwworm is a parasitic fly whose larvae feed on living tissue of warm‑blooded animals. Once eradicated from the United States through a nationwide sterile insect technique program that began in the 1950s, the species had not been reported in North America since the early 2000s. Recent detections in Mexico and now the United States have prompted renewed surveillance.
Under Secretary for Marketing and Regulatory Programs Dudley Hoskins said the USDA would share information quickly and transparently. “We are working closely with our partners in New Mexico, Texas and across the region to ensure we identify, contain, and respond to any potential cases as swiftly as possible,” he said.
Officials have also opened infestation sites in La Salle and Webb Counties for epidemiological investigation. Residents in the infested zones are advised to stay updated on movement requirements and other guidance.
The screwworm’s larvae can cause severe wounds in livestock, wildlife, and pets. In cattle, infestation can lead to significant economic losses through treatment costs, lost productivity, and, in severe cases, death. The fly’s presence in the United States raises concerns for the livestock industry, especially in Texas, where cattle ranching is a major economic activity.
The USDA’s Animal and Plant Health Inspection Service (APHIS) is leading the national response. APHIS has coordinated with state animal health agencies, the Texas Animal Health Commission, and the New Mexico Department of Agriculture to monitor the spread and implement control measures.
The detection of screwworm in Texas and New Mexico is part of a broader pattern of the species moving northward from Central America. The fly’s range has expanded in recent years, prompting the USDA to launch a “Grand Challenge” program in 2024 to fund research and control efforts.
The TAHC and USDA will continue to monitor the situation and provide updates on the status of the investigation. The agencies have urged animal owners in the affected areas to remain vigilant and report any signs of myiasis—infestation by fly larvae—to local veterinary authorities.
As of now, no human cases have been reported, and the USDA has not issued any travel advisories. The focus remains on containing the fly’s spread and protecting the livestock industry.
The next steps include detailed sampling of animals in the affected households, environmental assessments of the surrounding areas, and coordination with federal and state wildlife agencies to determine whether the screwworm has established a broader presence.
The USDA’s commitment to rapid information sharing aims to prevent further spread and mitigate economic impacts on the agricultural sector. The agencies will continue to update the public as new information emerges.
The dog case marks the first confirmed screwworm detection in New Mexico. Because the animal’s recent travel and exposure history remain unknown, the United States Department of Agriculture (USDA) and state partners are inspecting additional animals at the dog’s home. USDA officials described the situation as “isolated” while emphasizing that the agency is conducting a thorough investigation.
The New World screwworm is a parasitic fly whose larvae feed on living tissue of warm‑blooded animals. Once eradicated from the United States through a nationwide sterile insect technique program that began in the 1950s, the species had not been reported in North America since the early 2000s. Recent detections in Mexico and now the United States have prompted renewed surveillance.
Under Secretary for Marketing and Regulatory Programs Dudley Hoskins said the USDA would share information quickly and transparently. “We are working closely with our partners in New Mexico, Texas and across the region to ensure we identify, contain, and respond to any potential cases as swiftly as possible,” he said.
Officials have also opened infestation sites in La Salle and Webb Counties for epidemiological investigation. Residents in the infested zones are advised to stay updated on movement requirements and other guidance.
The screwworm’s larvae can cause severe wounds in livestock, wildlife, and pets. In cattle, infestation can lead to significant economic losses through treatment costs, lost productivity, and, in severe cases, death. The fly’s presence in the United States raises concerns for the livestock industry, especially in Texas, where cattle ranching is a major economic activity.
The USDA’s Animal and Plant Health Inspection Service (APHIS) is leading the national response. APHIS has coordinated with state animal health agencies, the Texas Animal Health Commission, and the New Mexico Department of Agriculture to monitor the spread and implement control measures.
The detection of screwworm in Texas and New Mexico is part of a broader pattern of the species moving northward from Central America. The fly’s range has expanded in recent years, prompting the USDA to launch a “Grand Challenge” program in 2024 to fund research and control efforts.
The TAHC and USDA will continue to monitor the situation and provide updates on the status of the investigation. The agencies have urged animal owners in the affected areas to remain vigilant and report any signs of myiasis—infestation by fly larvae—to local veterinary authorities.
As of now, no human cases have been reported, and the USDA has not issued any travel advisories. The focus remains on containing the fly’s spread and protecting the livestock industry.
The next steps include detailed sampling of animals in the affected households, environmental assessments of the surrounding areas, and coordination with federal and state wildlife agencies to determine whether the screwworm has established a broader presence.
The USDA’s commitment to rapid information sharing aims to prevent further spread and mitigate economic impacts on the agricultural sector. The agencies will continue to update the public as new information emerges.
