Update as of Aug. 19, 2025: The U.S. Food and Drug Administration (FDA) can now issue Emergency Use Authorizations (EUAs) for animal drugs to treat or prevent New World Screwworm (NWS), as declared by the U.S. Department of Health and Human Services (HHS). “Today we are taking decisive action to safeguard the nation’s food supply from this emerging threat,” says HHS Secretary Robert F. Kennedy, Jr. “This authorization equips FDA to act quickly, limit the spread of New World Screwworm, and protect America’s livestock.” Currently, no FDA-approved drugs exist for NWS in the U.S., but EUAs allow flexible, faster use of certain animal drug products approved for other purposes or available abroad. The FDA will provide guidance to veterinarians and stakeholders on the use of authorized products and update resources for animal health officials via the New World Screwworm: Information for Veterinarians page. Original news item, posted on Aug. 15: The U.S. Department of Agriculture (USDA) has announced new measures to combat the potential spread of New World Screwworm (NWS) from Mexico into the United States. According to the USDA, NWS is a dangerous parasitic fly whose larvae infest living animals, causing severe wounds that can be fatal. The pest poses a risk to livestock, pets, wildlife, and, in rare cases, humans. As part of its five-prong strategy to combat NWS, the USDA will build a sterile fly production facility in Edinburg, Texas, capable of producing up to 300 million sterile flies each week. The agency says the facility will complement similar programs in Mexico and Panama while reducing U.S. reliance on foreign facilities. USDA is also investing $100 million in research on new sterilization technologies, traps, and treatments. “We have assessed the information on the ground in Mexico and have determined we must construct an additional sterile fly production facility in the United States to stop the northward advancement of this terrible pest that is threatening American cattle production,” says Secretary Brooke Rollins in a release by the USDA. “The construction of a domestic sterile fly production facility will ensure the United States continues to lead the way in combating this devastating pest. If our ranchers are overrun by foreign pests, then we cannot feed ourselves,” Sec. Rollins adds. “USDA and Customs and Border Protection are constantly monitoring our ports of entry to keep NWS away from our borders. We are working every day to ensure our American agricultural industry is safe, secure, and resilient.” Additional measures include ramping up mounted patrols, training detector dogs to identify infestations, and coordinating with Mexican authorities to contain the pest south of the border. While NWS has not been detected in U.S. livestock, USDA warns it remains a serious threat to animal health, food safety, and the agricultural economy. For more information, visit the USDA website.
