Arizona officials confirmed the state’s first case of an animal diagnosed with New World screwworm (NWS).
This is the third state in the U.S. to report an animal case of the flesh-eating parasite. Previously, only Texas and New Mexico had reported infections among animals, according to data from the U.S. Department of Agriculture (USDA). Officials note that the risk to public health is low.
No human cases have been reported this year. Last year, a Maryland resident who recently returned from travel to El Salvador was found to be infected with NWS, a Department of Health and Human Services spokesperson told ABC News at the time.
The Arizona Department of Agriculture (AZDA) said on Wednesday that the case was identified in a canine in Cochise County, located in southeast Arizona on the border with Mexico.
A local veterinarian examined the animal on Monday and found a wound on the canine’s back “heavily infested with maggots” that were consistent with characteristics of NWS, according to AZDA. Testing confirmed the species.
The canine is currently under veterinary care, and AZDA said it is working with the attending veterinarian and the canine’s owner to gather additional information.
“We have been preparing for this possibility for a long while and are acting swiftly,” Dr. Ryan Wolker, state veterinarian, said in a statement. “Because of the extensive outreach, coordination and surveillance already in place, Arizona producers, veterinarians and pet owners know what to look for and how to report suspected cases. That preparation is allowing us to move quickly to protect animal health in the state.”
According to local officials, the USDA is responding by establishing an infested zone, increasing animal surveillance and performing outreach to local partners.
NWS is a species of parasitic fly that feeds on live tissue and can cause myiasis, which is an infestation of larvae, or maggots, according to the Centers for Disease Control and Prevention (CDC).
They can infest many types of animals, including livestock, pets, wildlife and, in rare instances, humans.
The name refers to the way in which maggots screw themselves into the tissue of animals with their sharp mouth hooks, causing extensive damage and often leading to death.
Screwworm was eradicated for decades in the U.S. through a technique in which male screwworm flies are sterilized and then released into the environment to mate with females until the population dies out. However, cases among livestock have migrated up through the southern border over the past year.
AZDA said it is calling for the release of sterile flies in the area to help suppress the fly population and “prevent the pest from becoming established.”
People who travel to outbreak areas, spend time among livestock animals, sleep outdoors and have an open wound are at greater risk of NWS, according to the CDC.
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