August 26, 2025 – The first human case of the New World screwworm in the United States in decades has been confirmed in a Maryland resident who recently traveled to El Salvador, federal health officials reported Monday.
The parasite, scientifically known as Cochliomyia hominivorax, is a type of fly larva that feeds on living tissue and can cause severe tissue damage if left untreated. The infected individual has fully recovered following medical treatment, according to the Centers for Disease Control and Prevention (CDC).
Authorities emphasized that the infection is not contagious and poses minimal risk to the general public. “Prompt treatment ensures recovery, and there is no evidence of transmission to others,” said a CDC spokesperson.
While human cases are extremely rare, New World screwworm has historically posed a significant threat to livestock. The United States eradicated the parasite from its agricultural populations in the 1960s, but recent outbreaks in parts of Central America have raised concerns about its potential reintroduction.
In response, the U.S. Department of Agriculture has continued preventive measures, including the use of sterile male flies to disrupt the parasite’s reproductive cycle in regions where it has been detected.
Health officials urged travelers returning from areas where the parasite is endemic to monitor for unusual wounds or infections and seek immediate medical attention if symptoms arise.
The incident serves as a reminder of the continued vigilance required to prevent the resurgence of parasitic infections in the United States.
