WASHINGTON, D.C. — The Centers for Disease Control and Prevention has activated a Level 3 emergency response following recent detections of New World screwworm infestations in animals in Texas and New Mexico, expanding federal efforts to prevent the parasite from becoming reestablished in the United States.
The June 11 activation places the CDC in a formal response posture as it supports the U.S. Department of Agriculture and the Texas Department of State Health Services in monitoring and containing outbreaks affecting livestock, wildlife and other animals.
Federal officials emphasized that there are currently no reported human cases in the United States and that the risk to the general public remains low.
New World screwworm is a parasitic infestation caused when flies deposit eggs in open wounds or body openings of animals or humans. After hatching, the larvae feed on living tissue, causing potentially severe injuries if left untreated.
The recent detections have been limited to animals in southern Texas and one county in New Mexico, according to federal officials. USDA is maintaining a public dashboard tracking confirmed animal cases.
Health authorities noted that New World screwworm does not spread directly between animals or from animals to people. Instead, infestations occur when flies lay eggs on a susceptible host.
The CDC’s response is part of a broader federal effort launched in 2025 to prevent the parasite from regaining a foothold in the United States. The campaign is coordinated through the U.S. One Health Coordination Unit–New World Screwworm Interagency Working Group, which is co-led by the USDA, CDC and Department of the Interior.
Federal agencies have pointed to previous eradication efforts as evidence the parasite can be eliminated from the country.
“NWS has been eradicated from the United States in the past, and CDC will support USDA and other partners to eradicate it again,” the agency stated.
The CDC is urging healthcare providers, particularly in affected areas, to remain alert for possible human infestations and to promptly report suspected cases to local or state health departments.
Veterinarians are also being asked to report suspicious animal infestations to state animal health officials and USDA Animal and Plant Health Inspection Service offices.
Additional information about New World screwworm, including updates on the federal response, is available at www.screwworm.gov. USDA’s animal case tracking dashboard is also available through federal agricultural response resources.
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