The New World Screwworm is now closer to the United States than it has been during the current outbreak, raising fresh concerns for cattle producers across the South and Southwest.
According to USDA reports, a confirmed case was recently found in a young sheep in Mexico’s Coahuila state, approximately 31 miles south of the Texas border. The discovery marks the closest confirmed detection to the U.S. since the parasite began spreading north through Mexico.
The New World Screwworm is not a disease. It is a flesh-eating fly whose larvae feed on living tissue. Infested livestock can suffer severe wounds, infections, weight loss, and in some cases death if not treated quickly.
The latest detection comes as federal officials continue efforts to stop the pest before it reaches U.S. soil. USDA data shows nearly 2,000 active cases remain under surveillance in Mexico, with multiple detections reported near the border region.
To slow the spread, U.S. and Mexican authorities are expanding the use of sterile male flies. The program releases sterilized insects into affected areas to reduce reproduction and eventually collapse screwworm populations. Officials say release numbers are expected to increase significantly in the coming weeks.
The threat has already impacted cattle trade. Earlier this year, the United States suspended imports of live cattle from Mexico as officials worked to limit the risk of the pest entering the country through livestock movement.
Meanwhile, USDA recently opened the new Knipling-Bushland Livestock Insects Research Laboratory in Kerrville, Texas. The facility will focus on developing new tools to combat livestock pests including ticks, biting flies, and the New World Screwworm.
State animal health officials across the southern United States continue to prepare for the possibility of a domestic outbreak. Livestock agencies have expanded monitoring efforts and are reviewing quarantine and response plans should the parasite cross the border.
Industry experts say producers should remain vigilant by checking livestock regularly for unusual wounds or signs of infestation, especially during the warmer months when fly activity increases.
While officials remain hopeful containment efforts will succeed, many in the cattle industry acknowledge the battle against screwworm is entering a critical stage as the pest moves closer to American ranches.
For now, USDA officials say surveillance, sterile fly releases, and rapid response measures remain the best tools available to keep the parasite from gaining a foothold in the United States.
Leave a Reply