Quarantine in Texas: US races to contain deadly flesh-eating parasite

Federal and state officials are responding to the first confirmed case of screwworm in the U.S. in decades, found on a farm in La Pryor, Texas. A calf was discovered infested with the flesh-eating parasite this week. U.S. Agriculture Secretary Brooke Rollins stated on Thursday that no other animal infestations have been detected near the confirmed case. This discovery is a concern for U.S. cattle ranchers, who have been anticipating a domestic outbreak as the New World screwworm fly has been advancing north through Mexico.

US agriculture and health officials are implementing a plan to combat a New World Screwworm outbreak, detected in Texas for the first time since 1966. The strategy involves releasing hundreds of millions of genetically-altered sterile flies to prevent reproduction, establishing a containment zone around the initial infection site in La Pryor, and using sniffer dogs for detection. While the threat to humans is low, cattle ranchers are concerned about the economic impact on beef markets. Current sterile fly production is insufficient to immediately halt the growing screwworm population, leading to criticism of the response. The screwworm, a parasitic fly, lays eggs in open wounds of warm-blooded animals, with larvae burrowing into living flesh.

The New World screwworm fly, whose larvae eat live flesh, has reappeared in the U.S. for the first time since 1966, with an infestation confirmed in a calf in south Texas. This parasite, which can affect any warm-blooded animal, poses a significant threat to the $113 billion U.S. cattle industry. Officials had been working to prevent its arrival after it was detected in Mexico in late 2024, following years of containment in Panama. The U.S. previously eradicated the fly in the mid-20th century by releasing sterile males. In response, Texas has imposed a quarantine zone, and the USDA is increasing its release of sterile flies, with new production facilities planned. The fly has sickened thousands of animals and hundreds of people in Central America and Mexico, with ten human deaths reported.

The US Department of Agriculture has confirmed the first New World screwworm case in a Texas calf in 60 years. This flesh-eating parasite, believed to have traveled from Central America, lays eggs in wounds of warm-blooded animals, with larvae consuming living tissue. While rare, humans can also be infected, and an outbreak could significantly impact the livestock industry, potentially costing the Texas economy $1.8 billion. The affected calf in LaPryor, Texas, is being treated, and a quarantine zone has been established. Authorities are implementing measures including vigilance, identification, isolation, treatment, and controlling animal movement, with sterile male release considered a long-term control method.

The New World screwworm fly, a flesh-eating parasite not seen in the US for decades, has been confirmed in a calf in southern Texas, near the Mexico border. This marks the first detection in the state since 1966. Agriculture officials are concerned about the potential threat to the cattle industry, as the parasite's larvae feed on warm-blooded animals. The USDA and Texas officials have been monitoring the parasite's spread in Mexico, where it has advanced significantly. While the risk to humans is low, the screwworm can spread rapidly among livestock. The US eradicated the screwworm in the 1970s, and efforts are underway to prevent re-establishment, including building a sterile fly production facility.