New World Screwworm
On June 3, 2026 USDA announced that New World Screwworm was detected in the United States. The affected animal was a 3-week-old bovine calf in Texas with larvae identified in the umbilical area. There have been no further detections.
New World Screwworm (NWS), Cochliomyia hominivorax, is a parasitic fly that completes part of its lifecycle by feeding on the tissue of warm-blooded animals and sometimes people. It does not spread directly from animals to people or from person to person. Until 2023, NWS was present in South America, but had previously been eradicated from North and Central America. Since 2023, however, the fly has steadily moved northward.
While the risk in Alaska is low due to the cool temperatures and environmental conditions, pet owners traveling to affected areas should be vigilant.
Animal owners must be in compliance with state and federal regulations for importing animals into the state of Alaska and into the United States. The applicable agencies are listed below.
- Alaska Office of the State Veterinarian (OSV): All animals entering Alaska, including dogs and cats, are required to have a Certificate of Veterinary Inspection (CVI) and meet other Alaska-specific requirements.
- U.S. Centers for Disease Control (CDC): The CDC regulates the import of dogs into the United States.
- U.S. Department of Agriculture Animal and Plant Health Inspection Service Veterinary Services (USDA APHIS VS): USDA regulates the import of horses and livestock into the country.
These import regulations help protect wildlife, livestock, and pets in our state from many contagious and infectious diseases and parasites, not just New World Screwworm.
The U.S. food supply is safe. Screwworms do not infest meat, fruits, vegetables, or other food sources.
USDA and partner state and federal agencies have been working together for the past year on a unified response to NWS. Additional information is available on the USDA and Texas Animal Health Commission NWS webpages.
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