Flesh-eating screwworm detected in Texas calf after decades

A case of New World screwworm, a flesh-eating parasitic fly that attacks warm-blooded animals, has been confirmed in a calf in Texas, the U.S. Department of Agriculture (USDA) announced on Wednesday evening, raising concerns about a significant threat to the nation’s cattle industry.

The infestation was identified in a calf in La Pryor, Texas, located about 30 miles (48 kilometers) northeast of the U.S.-Mexico border, News.Az reports, citing Reuters.

The discovery represents a major setback for U.S. cattle producers, who have been closely monitoring the northward spread of the parasite through Mexico over the past year amid fears that it would eventually reach the United States.

U.S. Agriculture Secretary Brooke Rollins said the case is the first confirmed screwworm infestation in Texas since 1966 and remains the only confirmed case in the country.

The parasite poses a serious risk to the U.S. cattle sector, which is already facing challenges due to the smallest national cattle herd in 75 years. Reduced livestock numbers have contributed to lower beef production and pushed consumer beef prices to record levels.

The detection also threatens Texas’ livestock industry, which experts estimate could suffer economic losses of up to $1.8 billion if the pest spreads further. The development marks a setback for long-running U.S. eradication and prevention efforts that have cost millions of dollars to keep the parasite from entering the country.

Texas Agriculture Commissioner Sid Miller criticized the USDA’s handling of the threat, arguing that federal authorities failed to act aggressively enough to prevent the screwworm’s arrival in the United States.

“Instead of using every available tool, USDA moved too slowly and relied solely on a partial solution that takes years to fully implement,” Miller said.

Rollins defended the agency’s strategy, stating that the release of sterile flies remains the most effective method for controlling the pest and noting that the USDA has made substantial investments in sterile fly production programs.

Earlier on Wednesday, Reuters reported that samples from a suspected screwworm infestation at a ranch in La Pryor had been submitted to the federal laboratory in Ames, Iowa, for testing. Following confirmation of the case, Chicago Mercantile Exchange feeder cattle futures extended their losses and closed 1.7% lower, reflecting concerns among traders that the outbreak could negatively affect beef demand.

New World screwworm flies are highly destructive parasites. Female flies lay their eggs in open wounds or mucous membranes of warm-blooded animals. After hatching, hundreds of larvae use sharp mouth hooks to burrow into living tissue, feeding on flesh and potentially killing the host animal if treatment is not provided. The parasite is primarily spread through the movement of infected animals.

Although screwworms can infest pets and humans, experts say the risk to people is low and human infections remain rare. The parasite also does not present any food safety concerns.

In response to the detection, the USDA said it has suspended the movement of animals within a 20-kilometer (12.4-mile) radius of the affected site in an effort to contain the outbreak. The agency has also released sterile screwworm flies in the area, expanded wildlife surveillance measures, and deployed a response team to South Texas.

Rollins added that an aircraft carrying stockpiles of screwworm treatment supplies was en route to South Texas to support containment and eradication efforts.

“Protecting our livestock industry is a national security issue of the utmost importance,” said USDA Under Secretary Dudley Hoskins.

News.Az 

By Nijat Babayev