Cattle ranchers in Texas and around the country are concerned that the screwworm, a parasitic fly that was once eradicated in the U.S., is threatening a comeback from the Mexican border and recent talk from President Trump about importing beef from Argentina is no long-term solution for a beef supply chain already under stress or consumers who have watched beef prices
hit record levels.
The New World screwworm is a parasitic fly that lays eggs in the open wounds of warm-blooded animals. The larvae then hatches from the eggs and burrows into tissue of animals to feed on them. If caught early, the sick animal can be treated and survive. Human cases are rare but can be painful and require medical attention. In August, the the U.S. Department of Agriculture said in a statement the Department of Health and Human Services and Centers for Disease Control and Prevention identified a case of the flesh-eating parasite in a person in Maryland who returned to the U.S. after traveling to El Salvador.
The New World screwworm was successfully eradicated from the United States in 1966. But the Maryland case and other recent appearances in Mexico have cattle ranchers in Texas and around the country on edge. Mexico’s National Service of Agro-Alimentary Health, Safety, and Quality confirmed on October 6 another case of the flesh-eating screwworm parasite in Nuevo Leon, a city that borders the U.S. It marked the country’s second confirmed case in approximately two weeks.
