06/05/2026
Flesh eating parasite confirmed in Texas
A rare flesh-eating parasite known as the New World screwworm has been confirmed in Texas for the first time since 1966, sparking concern among livestock producers.
The U.S. Department of Agriculture announced the detection in a three-week-old calf in Zavala County, near La Pryor, about 30 to 50 miles from the Mexico border.
Larvae were found in the animal's umbilical area, where female screwworm flies lay eggs in open wounds or mucous membranes.
The screwworm is the larval stage of a parasitic fly that feeds exclusively on living tissue of warm-blooded animals, including cattle, wildlife, and occasionally humans or pets.
Unlike common maggots that consume only dead flesh, screwworm larvae burrow deeper into healthy tissue, causing severe pain, tissue destruction, and potentially fatal infections if untreated.
This makes it a devastating threat to the cattle industry, as infestations can lead to significant economic losses through animal suffering and death.
The parasite had been eradicated from the United States in the 1960s through an innovative sterile insect technique, in which millions of irradiated male flies are released to mate with wild females, producing no viable offspring.
It had been advancing northward through Mexico, prompting heightened monitoring. Officials emphasize this is an isolated case with no evidence of wider establishment.
A quarantine zone has been implemented, sterile flies are being deployed, and surveillance intensified to prevent spread. Human risk remains very low, and there are no food safety concerns.
This development highlights vulnerabilities in border biosecurity amid shifting climate and trade patterns. Ranchers are urged to report wounds promptly and maintain vigilant animal health practices.
