Federal health officials confirmed the nation’s first travel-related human case of New World screwworm in a Maryland patient who recently returned from Central America, Reuters reported Monday.
Health and Human Services spokesman Andrew Nixon told Reuters the Centers for Disease Control and Prevention (CDC) confirmed the case, saying the traveler had come from El Salvador. But beef industry sources told the outlet the patient had traveled from Guatemala, a discrepancy Nixon did not address. (RELATED: ‘Flesh-Eating Parasite’ Menaces American Beef Industry)
“The risk to public health in the United States from this introduction is very low,” Nixon said.
The confirmation comes as cattle producers remain on edge over the parasite’s potential northward spread. The U.S. Department of Agriculture (USDA) estimates a screwworm outbreak could cost Texas roughly $1.8 billion in livestock deaths, labor and medication expenses, according to Reuters.
ATLANTA, GEORGIA – AUGUST 9: Bullet holes are seen in windows at the Centers For Disease Control (CDC) Global Headquarters following a shooting that left two dead, on August 9, 2025 in Atlanta, Georgia. (Photo by Elijah Nouvelage/Getty Images)
State veterinarians learned about the case through unofficial channels before the CDC acknowledged it, according to South Dakota state veterinarian Beth Thompson. (RELATED: Trump Admin Ramps Up Fight Against ‘Flesh Eating Parasite’ Threatening US Cattle Industry)
“We found out via other routes and then had to go to CDC to tell us what was going on,” Thompson told Reuters. “They weren’t forthcoming at all. They turned it back over to the state to confirm anything that had happened or what had been found in this traveler.”
The government has not confirmed any animal cases this year, according to the outlet. USDA Secretary Brooke Rollins announced plans last week to build a sterile fly facility in Texas to combat the pest.
A Beef Alliance executive alerted approximately two dozen livestock and beef sector contacts about the Maryland case last week, an anonymous industry source told Reuters. A Maryland state government official also confirmed the case, though the state health department did not respond to the outlet’s requests for comment.