Flesh-Eating Screwworm Invasion in the United States
A deadly parasite, the New World Screwworm, has re-emerged in the U.S. after decades, prompting international trade restrictions and public health concerns.
June 2026
USDA APHIS confirms New World screwworm detection in Texas
The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) confirmed the detection of a New World screwworm (NWS). The worm was found in a 3-week-old calf in Zavala County, Texas.
Source ↗Agriculture Secretary addresses screwworm misinformation
Agriculture Secretary Brooke Rollins addressed reports regarding the New World screwworm. She stated that misinformation was creating unnecessary concern and affirmed the department's commitment to accurate information.
Source ↗Calf in Texas tests positive for screwworm parasite
A calf at a ranch in Texas tested positive for the flesh-eating parasite. This marked the first confirmed case in Texas since 1966.
Source ↗USDA detected New World Screwworm in Texas cattle
The US Department of Agriculture (USDA) announced the first detection of New World Screwworm in a calf in Texas. The case was confirmed in La Pryor, Texas, near the US-Mexico border.
Source ↗USDA and Texas authorities establishing quarantine zone
Due to the spread risk, the USDA and Texas authorities are establishing a 20km detection and quarantine zone. This measure aims to control the movement of infested animals.
Source ↗USDA Secretary rolls out support to South Texas
Agriculture Secretary Brooke Rollins confirmed that USDA personnel arrived in South Texas to support ongoing operations. She urged livestock producers to remain vigilant.
Source ↗USDA confirms New World Screwworm in South Texas calf
The U.S. Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS) confirmed New World screwworm (NWS) in cattle in South Texas. The pest was found in the umbilical area of a three-week-old calf.
Source ↗USDA establishes quarantine zone in South Texas
The USDA created a 20-kilometer “infested zone” and implemented quarantines, movement control, and surveillance in the area around the infected calf’s herd. This measure requires the infection to be contained or controlled for removal.
Source ↗USDA halted cattle imports from Mexico
Before the detection in South Texas, the USDA had shut down the U.S.-Mexico border to cattle imports due to reports of NWS cases in Mexico.
Source ↗USDA detects five New World screwworm cases in Texas and New Mexico
The U.S. Department of Agriculture announced five cases of New World screwworm (NWS). These cases were detected in Texas and New Mexico within the span of a week.
Source ↗Three calves and goat confirmed with NWS in Texas
Three calves and one goat in Texas were confirmed to have NWS. These confirmations were part of the recent detection of the parasite.
Source ↗USDA investigates dog case; potential link to Mexico
The USDA detected the first case of NWS in a dog in Lea County, New Mexico. The USDA is investigating this animal and its movement history, noting the dog may have traveled from Mexico.
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