U.S.|Texas Races to Contain First U.S. Screwworm Case Since the 1960s

Gov. Greg Abbott of Texas said on Friday that the state is working with the federal government to slow the spread of the New World screwworm days after the first case was detected in the United States in decades.

Flanked by state officials, Mr. Abbott said in a press briefing that Texas, led by the Agriculture Department, is dispersing millions of sterile male New World screwworm flies that will mate with wild female flies, preventing them from producing offspring and gradually driving the population toward eradication. He also signed a statewide disaster declaration to ensure that the affected areas received resources ahead of what he said is likely to be “an extraordinarily challenging summer to get through this.”

“We’re in the season for spread,” he said.

The move comes two days after the Agriculture Department confirmed the first case of screwworm since the 1960s in a three-week-old calf in La Pryor, Texas, a rural ranch area 97 miles southwest of San Antonio. The screwworm is a fly whose larvae feed on the tissue of livestock, wildlife and pets that has long been eradicated in the United States.

The officials did not report any new cases.

The news unnerved the cattle and beef industries in Texas, long considered the heart of the American beef industry. Texas leads the nation in beef production, with more than 4.1 million cattle, and accounts for about 15 percent of beef production in the United States, according to the Texas Agriculture Department.

Even before the confirmed case in Texas, the beef industry was facing its fair share of challenges. The American cattle inventory has diminished to its lowest levels since 1952 partly due to persistent droughts and high feed prices. Domestic beef prices continue to climb to record highs.

The screwworm had been eradicated by the mid 2000s from all of North and Central America. But the parasite resurfaced in 2024 after it was detected along Mexico’s border with Guatemala. More than 20,000 cases have been detected in Mexico alone in recent years resulting in the United States barring the entry of all Mexican cattle for more than a year.