USDA and HHS Confirm Travel-Related Human Case of New World Screwworm in Maryland

Courtesy of USDA/APHIS
The Department of Health and Human Services (HHS) and the U.S. Department of Agriculture (USDA) have confirmed a travel-associated case of New World Screwworm (NWS) in the United States. The case was identified in Maryland, in a patient returning from El Salvador.
This marks the first confirmed U.S. case of NWS in a human in 2025.
“Many federal departments including the USDA, HHS, CDC and FDA along with the Maryland Department of Health participated in the investigation and confirmation of the case and no additional detections of New World Screwworm have been confirmed.”
Federal officials stress that the public health risk is very low.
“According to the USDA, public health risk in the US from this case is very low and out of an abundance of caution, USDA has initiated a targeted surveillance of NWS within 20 miles of the affected area including parts of Washington DC, Maryland and Virginia.”
So far, all trap results for NWS have returned negative.
The last known outbreak in animals occurred in 2017 in the Florida Keys, and it was successfully resolved.
“Past human detections of NWS have been isolated and targeted surveillance were closed after negative results were observed.”
Federal officials are closely monitoring for any new developments.
“We may continue to see traveler-associated cases of NWS and USDA, in coordination with HHS and CDC, will conduct targeted surveillance to ensure there is no active spread of NWS in the United States. This is not cause for alarm as human risk is low and we have seen several isolated cases in recent years that have not resulted in livestock transmission.”
The USDA remains focused on preventing NWS from spreading to U.S. livestock. This case aligns with USDA Secretary Brooke Rollins’ plan to actively detect and manage screwworm threats.
“USDA is continuing forward in their efforts to combat NWS in livestock as outlined in US Secretary of Agriculture Brooke Rollins’ earlier announced plan to ‘detect, control, and eliminate New World screwworm.’”
Audio Reporting by Dale Sandlin for Southeast AgNet.