Arizona Becomes 3rd State to Confirm Case of New World Screwworm
By Darryl Coote
Agriculture officials on Wednesday announced that a case of New World screwworm was discovered in Arizona. File Photo by Annabelle Gordon/UPI | License Photo
Oct. 29, 2026 / 4:00 AM
Arizona agriculture officials have announced the state's first case of New World screwworm, making it the third U.S. state to report a case of the flesh-eating parasite amid the ongoing outbreak.
Discovery and Confirmation
The parasite was found in a heavily maggot-infested wound on a dog's back in Cochise County by a local veterinarian who examined the animal Monday evening. Samples from the dog were tested and confirmed on Wednesday by the U.S. Department of Agriculture (USDA).
The infected dog was under veterinary care, and Arizona Department of Agriculture (AZDA) was working with the veterinarian and the dog's owner to gather information about the infection.
Rapid Response and Investigation
"We have been preparing for this possibility for a long while and are acting swiftly," stated Dr. Ryan Wolker, Arizona's state veterinarian.
The USDA established a 20-km (12.4-mile) infested zone around the site of the detection, releasing sterile flies and increasing live animal surveillance. They are also trapping and implementing targeted outreach to local producers, veterinarians, and communities.
Growing Outbreak
Seventy-one cases of New World screwworm have been detected in the United States—18 that are currently active—since the first case was reported on June 3. Cases were also detected in New Mexico and Texas.
The current outbreak began in Panama and Costa Rica in 2023, and since then, cases in animals and people have been reported across Central America, Mexico, and now three southern U.S. states.