Arizona now has seven confirmed cases of New World screwworm in four southern counties, state agriculture officials said, after a horse near Tucson tested positive.
The Arizona Department of Agriculture announced Friday that a pet equine near Tucson tested positive — the first case in Pima County and roughly 83 miles from the state’s first documented case. Pima County officials confirmed the case Saturday and described the animal as a domesticated horse with “no known history of travel.”
By county, state data shows three cases in Cochise County and two in Greenlee County, with Graham and Pima counties each reporting one.
Officials have established a new infested zone in Pima County, a mandatory quarantine area set at a 20-kilometer radius around each affected property. Infested zones now include areas around Tucson, Sierra Vista, Elfrida and Safford. Animals cannot leave these zones until movement restrictions are lifted unless approved under certain conditions, according to the department.
The newest case comes nearly a week after Arizona began requiring owners of pets traveling to California to provide proof that the animal is not infected.
Pima County Health Department director Dr. Theresa Cullen said the risk to humans remains low but urged residents to seek medical attention promptly for open, draining or non-healing wounds and to watch for signs of insect infestation such as visible maggots.
The Pima Animal Care Center is pre-treating all dogs ahead of its Fall Festival adoption event, and state and county officials will host a virtual town hall on November 16 from 7:30 to 10:30 p.m. Eastern (5:30 to 8:30 p.m. Arizona time).
New World screwworm is a parasitic fly that lays its eggs in open wounds and can infest livestock, pets and people, according to the Centers for Disease Control and Prevention.
Correction: An earlier version incorrectly stated that there had been no reported human cases in the United States. That statement has been removed.
Sources and more information: Arizona’s Family (AZFamily), KGUN 9 Tucson, and the Arizona Department of Agriculture.
