From Nebraska Veterinary Diagnostic Center
The recent detection of New World Screwworm (NWS) in Texas has raised concerns about spread of this foreign animal disease agent that was eradicated decades ago. Since 2022, the spread of NWS throughout Central America and Mexico has allowed for continued risk monitoring and proactive planning by US regulatory agencies. Immediate actions being taken to contain and eradicate this incursion include:
- Establishment of a control zone,
- Targeted sterile fly release,
- Enhanced surveillance and outreach.
NWS is a reportable disease. If you suspect a case of NWS, report immediately to your local accredited veterinarian, the Nebraska Department of Agriculture (402-471-2351) or the local USDA APHIS office (402-434-2300). Additional information can be found in New World Screwworm What You Need to Know on the USDA APHIS website. The FDA’s Center for Veterinary Medicine also has released New World Screwworm: Information for Veterinarians with additional drug related information. For non-suspect diagnostic cases, NVDC can perform identification or referral of adult flies and fly larvae (maggots) as needed.
Larvae Identification Best Practices
- Flies and/or larvae should be placed in sealable containers (e.g., glass vials, plastic vials) with alcohol, preferentially 70-90% ethanol.
- Flies and larvae do not have to be refrigerated or frozen if submerged in alcohol.
- The more larvae submitted, the better, to ensure the presence of identifiable characteristics. Different sizes of larvae, if present, should be submitted.
- Vials should be shipped using ambient temperature packing with absorbent material, placed in a plastic bag to avoid spillage through the packaging, and placed in a rigid box.
- Samples can be submitted using our ruminant submission form with a test request for Parasite ID.
- Mailing labels can be ordered and printed directly from our Shipping webpage.
- Samples may be required to be forwarded to USDA for confirmatory identification. There is no additional cost for this.
Contact us with your questions
For fly specific questions:
Roberto Cortiñas, DVM, Ph.D.
Professor of Practice
School of Veterinary Medicine and Biomedical Sciences
University of Nebraska–Lincoln
113 VBS, Lincoln, NE 68583-0905
Phone: 402-472-6502
Email: rcortinas@unl.edu
Other questions:
J. Dustin Loy, DVM, Ph.D., Dipl. ACVM
Professor and Director
Nebraska Veterinary Diagnostic Center
School of Veterinary Medicine and Biomedical Sciences
Phone: 402-472-1434
Email: jdloy@unl.edu