In the late 1950s, the United States fought a winged enemy by USDA estimate. It sounds like science fiction, but it was how officials helped eradicate New World screwworm, a parasitic fly whose larvae feed on living tissue. For decades, that victory kept U.S. livestock, pets, wildlife, and people largely protected. Now, the old enemy is back on the map.
The U.S. Department of Agriculture confirmed the first U.S. animal case in the current outbreak on June 3, 2026, in Texas. Since 2023, the outbreak has moved north through Central America and Mexico, according to the Centers for Disease Control and Prevention (CDC). The CDC says no locally acquired human infestations have been reported in the United States, but the risk is real because New World screwworm can infest livestock, pets, wildlife, and people.
New World screwworm flies are attracted to wounds and body openings, where they lay eggs. Those eggs hatch into larvae that feed on live tissue, causing painful, worsening wounds that can become serious without treatment, according to the CDC. Screwworm infestations can be fatal to cattle and other livestock.
For ranchers, veterinarians, public health officials, and emergency managers, the concern is both biological and operational. In Mexico, screwworm-related export restrictions have cost cattle exporters more than $1.3 billion. And in Texas alone, a widespread outbreak could drain as much as $1.8 billion a year from ranchers and the wider economy, according to a USDA estimate.
The spread has already triggered a coordinated federal and state response. USDA's screwworm response site now lists recent case updates in Texas and New Mexico. At the same time, Texas animal health officials say federal and state partners are conducting surveillance, investigations, and response protocols in affected zones.
Why you should care: For industry professionals, screwworm is a reminder that risk can manifest far outside the office. A livestock parasite can become a supply chain issue, a travel concern, a field-worker safety risk, a public health communication challenge, and a business continuity problem.
Organizations with agricultural operations, outdoor workers, border-region facilities, veterinary exposure, logistics networks, or employees who travel with pets should watch official guidance closely. The practical lesson is familiar: know who is affected, verify the threat, communicate early, and make reporting easy. In fast-moving incidents, silence and uncertainty create their own kind of exposure. |
