Federal authorities confirmed a New World screwworm fly infestation in a calf in South Texas this week.
The detection of the flesh-eating parasite poses a significant risk to the U.S. cattle industry, which is valued at approximately $113 billion [1]. Because the parasite can devastate entire herds, the discovery has triggered an immediate federal response and a local quarantine to prevent the pest from spreading.
The case was identified in La Pryor, located in South Texas near the U.S.-Mexico border [2]. The infected animal was a calf only three weeks old [3]. Officials said they are working to contain the outbreak in this border region to protect the broader national food supply [2].
This represents a rare occurrence of the parasite within the United States. While some reports suggest this is the first detection in nearly a decade, other records indicate it is the first confirmed case since 1966 [4]. This discrepancy highlights the rarity of the parasite's presence in the region over the last 60 years [4].
The New World screwworm is particularly dangerous because it targets living tissue. Unlike other fly larvae that feed on dead matter, these parasites burrow into the flesh of warm-blooded animals, creating open wounds that attract further infestation [2].
USDA officials said they have established a quarantine zone around the affected area in La Pryor [2]. This measure is intended to stop the movement of livestock and prevent the parasite from migrating further into the U.S. interior. The agency said it is monitoring the situation closely to ensure the infestation does not escalate into a wider agricultural crisis [2].
“The parasite can devastate cattle herds, threatening the roughly $113 billion U.S. cattle industry.”
The reappearance of the New World screwworm in Texas underscores the vulnerability of the U.S. agricultural sector to transboundary animal diseases. Because the parasite targets living tissue and can spread rapidly through livestock populations, a single case can trigger massive economic disruptions. The federal quarantine is a critical step in preventing a systemic collapse of cattle productivity in the border region.
