New World Screw Worm

USDA Deputy Secretary Provides Update on NWS Detection and Prevention

Dan Beef, Cattle, Pest/Pest Control

USDA Deputy Secretary Stephen Vaden Updates on New World Screw Worm Prevention Efforts

New World Screw Worm
New World screwworm (NWS, Cochliomyia hominivorax) is a devastating pest. When NWS fly larvae (maggots) burrow into the flesh of a living animal, they cause serious, often deadly damage to the animal. NWS can infest livestock, pets, wildlife, occasionally birds, and in rare cases, people.
Courtesy of USDA/APHIS

During last week’s Farm Progress Show in Illinois, U.S. Department of Agriculture Deputy Secretary Stephen Vaden provided an important update on the New World Screw Worm, a pest posing a threat to livestock and humans. Vaden addressed recent concerns following a human detection case, sharing crucial insights on the history and current prevention measures.

“Believe it or not, we have had human cases in the past, including in the past five years,” Vaden explained. “Unfortunately, this happens at times where people go to regions of the Western Hemisphere where the fly is endemic. It’s bad for that particular human, although it’s easily treatable with modern medicine.”

The New World Screw Worm is a parasitic fly known for infesting wounds in warm-blooded animals, causing severe damage to livestock and wildlife. The pest’s potential to spread into the United States has raised alarm among agricultural and public health officials.

Deputy Secretary Vaden also emphasized the USDA’s ongoing collaboration with Mexico to prevent the fly from crossing into U.S. territory. “USDA’s Animal and Plant Health Inspection Service will be sending a team to Mexico in about two weeks’ time in order to review whether Mexico is following the protocols that we have agreed on and get an in-depth, on-the-ground look at the situation in Mexico,” he said. The team will report their findings to the Secretary and Vaden, who will then decide on the next steps.

Currently, the fly is located approximately 400 miles from the U.S. border at its closest point. “Right now, items including baiting are being done in Mexico,” Vaden noted. “We’re trying to ensure that we can keep this pest located where it is and no further. We’re doing this a few points north of the polygon where we know where it is to detect any movement early.”

This proactive effort highlights the USDA’s commitment to protecting U.S. agriculture and livestock from invasive pests. Continued vigilance and international cooperation remain key to keeping the New World Screw Worm at bay and safeguarding the nation’s food supply.

USDA Deputy Secretary Provides Update on NWS Detection and Prevention

Audio Reporting by Dale Sandlin for Southeast AgNet.