The U.S. Department of Agriculture confirmed Wednesday that a New World screwworm was detected in a calf in South Texas [1].
The discovery of the flesh-eating parasite represents a significant biosecurity threat to the American agricultural industry. Officials said the pest can devastate livestock and threaten national food-production capacity, potentially causing billions of dollars in economic losses [1, 5].
The infected animal was a three-week-old calf [1] located in La Pryor, within Zavala County [2, 3]. This site is approximately 161 km southwest of San Antonio and 80 km from the U.S.-Mexico border [3].
This is the first time the New World screwworm has been detected in the U.S. since it was eradicated from the country in 1966 [2]. The parasite is a fly whose larvae burrow into the living flesh of warm-blooded animals, causing severe tissue damage and often death if left untreated.
Texas officials and the USDA have initiated quarantine measures to contain the outbreak and prevent the parasite from spreading to other livestock populations. The agency said it is working to identify the source of the infection and monitor surrounding ranches for further cases [1, 3].
Agricultural experts said the proximity of the detection to the border is a critical factor in the containment strategy. Because the parasite can be transported by insects or animal movement, the USDA is implementing strict surveillance protocols to protect the cattle industry from a wider infestation [3, 4].
“The discovery of the flesh-eating parasite represents a significant biosecurity threat to the American agricultural industry.”
The re-emergence of the New World screwworm after six decades of eradication poses a direct risk to the U.S. beef and dairy sectors. Because the parasite targets living tissue rather than dead flesh, it can rapidly incapacitate healthy livestock, leading to massive productivity losses and increased costs for veterinary intervention. The location near the U.S.-Mexico border suggests a potential cross-border transmission, necessitating an aggressive federal response to prevent the parasite from establishing a permanent foothold in North American livestock.
