Why Cochise County Is On High Alert For The New World Screwworm

The Cochise County Government Facebook page shared a press release on Monday about the New World screwworm and the county’s planned response.

According to the press release, Cochise County District 2 Supervisor Kathleen Gomez is working with federal, state, local, and binational partners to “support efforts aimed at protecting Arizona’s livestock industry from the New World Screwworm”, which includes ongoing discussions with the US Department of Agriculture.

Joel Angel Juarez, Getty Images

The conversations center around “the potential establishment of a sterile fly distribution center at the Bisbee-Douglas International Airport (BDI).”

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What Is the New World Screwworm?

According to the American Society for Microbiology (ASM), the New World screwworm is a parasitic fly whose larvae feed on living tissue. They’re far more dangerous than typical maggots. According to the USDA, the larvae “burrow into the flesh of a living animal” and can cause serious, often deadly damage.

The screwworm typically infects warm-blooded animals, livestock, pets, wildlife, and sometimes even people.

Joel Angel Juarez, Getty Images

The Centers for Disease Control and Prevention (CDC) reports that infestations begin when flies lay eggs in open wounds or within body openings, and they can even infest very small cuts or bites.

According to the Arizona Department of Fish and Game (AZFGD), once hatched, the maggots “screw” into tissue, causing painful, foul-smelling wounds that expand the tissue damage and often lead to secondary infections.

READ: Xeriscaping and Water Harvesting to Save Water in Arizona

herd of cows on grassland

Why Cochise County Is Taking It Seriously

As of now, no infections or outbreaks have been reported in Cochise County. Officials are keeping a careful eye on potential outbreaks. Our proximity to the border and strong ranching economy make our area especially vulnerable.

In the June 22nd press release, the county stressed it has a “direct stake” in this potential threat, since animal health concerns can quickly become economic threats if not addressed early.

Joel Angel Juarez, Getty Images

Recently, the CDC confirmed cases of young cattle in Texas, which heightened concerns in Arizona.

Local leaders are especially worried about livestock losses, trade impacts, and the rapid spread of infestations. Because larvae can kill animals in as little as a week, the University of Arizona Cooperative Extension warns that early prevention is critical.

READ: What Arizona Horse Owners Need To Know About EHV1 Outbreak

housefly on board

What Agencies Are Doing to Stop It

Cochise County and Arizona agencies are working with federal partners, such as the USDA, to prepare a layered response. This includes:

• Sterile fly programs: Releasing sterile male flies to stop reproduction, a method proven to eradicate the pest before.
• Surveillance and reporting: Ranchers and veterinarians are urged to report suspicious wounds immediately.
• Border coordination: Cochise County is exploring the establishment of a sterile fly dispersal center at Bisbee-Douglas International Airport.
• Preventive barriers: Arizona is deploying fly traps, monitoring livestock, and limiting risk from affected regions.

This is a coordinated, multi-agency effort to prevent the pest from gaining a foothold in Arizona.