CDC Launches Level 3 Response as New World Screwworm Threat Grows
The Centers for Disease Control and Prevention (CDC) activated a Level 3 emergency response for New World screwworm (NWS) on June 11, 2026, to support ongoing efforts to prevent the parasite from spreading in the United States.
A Level 3 response represents the agency’s lowest emergency activation level but allows for coordinated action with federal and state partners.
The CDC is working alongside the U.S. Department of Agriculture (USDA) and the Texas Department of State Health Services following the recent discovery of New World Screwworm infestations in animals in southern Texas and a county in New Mexico.
USDA continues to monitor and report affected locations through its public tracking dashboard.
Although the parasite mainly targets livestock, wildlife, and pets, humans can also become infected if flies deposit eggs in open wounds or natural body openings.
At this time, no human cases have been identified in the United States, and health officials said the overall public risk remains low. The infestation cannot spread directly between animals or from animals to people.
Federal agencies began a coordinated response in summer 2025 through the U.S. One Health Coordination Unit–New World Screwworm Interagency Working Group, led by USDA, CDC, and the Department of the Interior. Their goal is to stop the parasite from becoming established in the country once again.
The CDC is urging healthcare providers, especially in affected regions, to remain alert for possible human infestations and report suspected cases to public health officials.
Veterinarians are also encouraged to notify state animal health authorities and USDA APHIS if they observe suspicious infestations in animals.
Photo Credit: usda