USDA Confirms First Screwworm Infection Since 1960s Eradication

The United States Department of Agriculture (USDA) this week confirmed the first known infection of flesh-eating screwworms in the United States. The carnivorous fly larvae feast on the flesh of living mammals, representing a parasitic threat that had previously been eliminated from the country.

The confirmation marks the return of the parasitic insects decades after the United States successfully eradicated them in the 1960s. At that time, the elimination of screwworms was considered a major achievement in pest control and agricultural management.

Screwworms are carnivorous fly larvae that feed on the flesh of living mammals. The parasitic nature of these insects distinguishes them from other types of fly larvae, as they target living tissue rather than dead or decaying matter.

The USDA's confirmation this week represents the first known infection of screwworms since the eradication effort concluded. The last known presence of these parasites in the United States dates back to before their elimination in the 1960s. The re-emergence of the pest raises concerns for agricultural officials who had considered the threat resolved for over half a century.