New World Screwworm

​The New World screwworm (Cochliomyia hominivorax) is a parasitic fly that lays its eggs in the open wounds and mucous membranes of warm-blooded animals, including livestock, pets, and in rare cases, humans.  The larvae, or maggots, feed on the living flesh of the host, which can lead to severe damage and potentially death if left untreated.  The U. S. eradicated the screwworm in 1966, but a recent northward progression of cases from Central America has renewed concerns.  A sterile insect technique, which involves releasing sterilized male flies to prevent the reproductive cycle, is a key tool in eradicating the pest.

COMMUNITY
CDC:  New World Screwworm Fly Myiasis
USDA:  New World Screwworm Fly Story Map  
University of Florida:  Screwworm Fly
New World Screwworm and Agriculture Employees
New World Screwworm and Agriculture Producers

HEALTHCARE PROVIDERS
CDC: New World Screwworm Health Advisory, Jan. 20. 2026 - Outbreak Moves into Northern Mexico
CDC:  New World Screwworm Fly Myiasis
CDC:  About New World Screwworm Myiasis
CDC:  Clinical Overview of New World Screwworm Myiasis
CDC:  Clinician Outreach and Communication Activity

LOCAL HEALTH DEPARTMENTS
HHS:  Health & Human Services and United States Department of Agriculture Confirm Singular Traveler-Associated New World Screwworm Case; Precautionary and Proactive Surveillance Ongoing
Maryland Dept. of Health:  Maryland Department of Health Confirm New World Screwworm Fly
Interim Considerations for Advanced Readiness and Preparedness for New World Screwworm (NWS) infestations in Humans

TESTING

CDC:  DPDx – Laboratory Identification of Parasites of Public Health Concern