ENVIRONMENT

Parasitic Screwworm Returns to Texas and New Mexico

PUBLISHED Sep 22, 2026, 11:33 AM ET

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The flesh-eating New World screwworm parasite, which was successfully eradicated from the United States decades ago, has returned and spread into regions of Texas and New Mexico. The U.S. Department of Agriculture and state agricultural authorities have activated emergency containment protocols, placing livestock movement restrictions and monitoring zones across affected counties. Unlike contagious respiratory viruses, the screwworm does not transmit person-to-person; instead, female flies infest open wounds of warm-blooded animals, threatening livestock, pets, and wildlife. To combat the re-emergence, the USDA is deploying the sterile insect technique, releasing millions of radiation-sterilized male flies to suppress the population, echoing the successful mid-20th-century eradication campaign. Additionally, a newly launched CDC-funded tracking dashboard developed by the University of California, San Diego provides real-time risk profiling to help authorities predict where the parasite may spread next. Current emergency responses remain active across the Southwest.

By Shahbaz A. | JQJO News

Timeline of Events

Mid-20th century — A historic federal eradication campaign successfully eliminates the New World screwworm from the United States.
Decades ago — The flesh-eating parasite remains absent and fully eradicated from U.S. territory for decades.
On September 15 2026 USDA and UC San Diego researchers release surveillance tracking updates confirming the return and northward spread of the screwworm into Texas and New Mexico.
On September 15 2026 USDA-APHIS activates emergency containment protocols, updating infested zones and establishing livestock movement restrictions.
On September 15 2026 USDA deploys the sterile insect technique while UC San Diego launches a CDC-funded real-time risk tracking dashboard.

News Intelligence

Immediate US impact: Livestock producers and animal owners in Texas and New Mexico face movement restrictions, quarantine zones, and heightened biosecurity protocols.
Possible long-term US impact: The ongoing incursion requires sustained federal deployment of sterile insect techniques and regional monitoring to prevent nationwide agricultural disruption.
Most affected groups: Livestock producers, veterinarians, pet owners, and residents in affected Texas and New Mexico counties.
Reader priority: High