U.S. health officials have confirmed the nation’s first human case of travel-associated New World screwworm, a flesh-eating parasite rarely seen in people. The patient, treated in Maryland after returning from El Salvador, was identified by the Centers for Disease Control and Prevention on 4 August and publicly disclosed by the Department of Health and Human Services on 24 August. HHS spokesman Andrew Nixon said the risk to the broader U.S. public is “very low.” No animal infections have been reported domestically this year. The screwworm fly’s larvae consume living tissue and can kill livestock if infestations are not detected early. The parasite was eradicated from the United States in the 1960s but has moved north through Central America and Mexico since 2023, prompting renewed vigilance along the U.S. border. Industry groups warn that an outbreak in cattle could roil already tight beef markets. The USDA estimates a full-scale infestation could cost Texas alone about $1.8 billion in losses and control measures. Agriculture Secretary Brooke Rollins last week detailed a $750 million plan to build a sterile-fly production facility in Edinburg, Texas, aimed at releasing billions of non-breeding males to suppress wild populations. Federal and state authorities have intensified surveillance of livestock imports, expanded insect trapping programs and advised clinicians to consider screwworm in patients with non-healing wounds who have traveled to affected areas. Officials say prompt detection and treatment remain critical to preventing the parasite from gaining a foothold in U.S. herds.