More New World screwworm has been detected. Latest updates for NC

The New World screwworm, a parasitic fly eradicated from the United States in the 1960s, has resurfaced in the American Southwest. Here’s what North Carolina residents, pet owners and cattle producers should know about the risk.

FULL STORIES:

• Could the return of New World screwworm impact beef prices in NC? Expert opinion
• New World screwworm is back, and it can kill pets. How to treat it in NC

Here are key takeaways:

• As of June 28, 26 cases have been detected — 25 in Texas and one in a dog in New Mexico — with no cases reported in North Carolina. On June 10, six total cases were confirmed in the United States.
• The screwworm lays eggs in open wounds on mammals, and the larvae feed on living flesh. It was eliminated from the U.S. in 1966 but has been moving north through Mexico since 2023, according to the USDA.
• Zach Raff, an assistant professor of agricultural and resource economics at NC State, previously told the Observer the parasite poses low risk to North Carolina as long as infected animals are quarantined. The adult fly can only travel 10 to 15 miles on its own.
• Beef prices could rise if the screwworm reaches major cattle states like Nebraska, where ranches would face higher veterinary costs and supply chain disruptions could prevent shipping calves out of North Carolina for finishing.
• The FDA authorized generic Nitenpyram Tablets as the first generic animal drug to treat screwworm infestations in dogs and cats weighing at least two pounds. The medication kills most larvae within hours of the first dose.
• Suspected cases must be reported. In North Carolina, contact the Department of Agriculture and Consumer Services Veterinary Division at 919-707-3250.

Eva Flowe

The Charlotte Observer

Eva Flowe is a North Carolina native and a graduate of the University of South Carolina. She joined the Charlotte Observer as part of the NC service journalism team in April 2026.