Mexico Launches Emergency Response to Livestock Screwworm Outbreak
Mexico has launched a national health and economic response after the re-emergence of the New World screwworm threatened its livestock industry and forced the suspension of cattle exports to the United States.
President Claudia Sheinbaum’s administration has announced large-scale livestock inspections, reinforced pest surveillance, and a $40 million livestock conversion program aimed at stabilizing the industry.
The outbreak, first detected in southern Mexico, has since spread north to Coahuila and Tamaulipas, prompting U.S. authorities to halt cattle imports to prevent the pest from crossing the border. The suspension affects roughly 650,000 head of cattle and represents an estimated $1.3 billion in losses, according to Mexico’s National Agricultural Council.
The New World screwworm (Cochliomyia hominivorax) is a parasitic fly whose larvae feed on the living tissue of warm-blooded animals, causing myiasis, a potentially fatal infection if untreated.
Mexico’s Secretary of Agriculture and Rural Development, Julio Berdegué, reported that over 1.8 million animalshave been inspected. Authorities are deploying traps, larvicidal treatments, and ivermectin protocols to contain the outbreak.
Reopening the U.S. border will depend on official certification confirming that Mexico is once again free of the pest. The country successfully eradicated screwworms in 1991 through a joint program with the United States and Central America, but experts warn that reinfestation risks remain high, especially along Mexico’s southern border.
“Beyond the economic impact, the outbreak exposes the fragility of epidemiological surveillance systems and the need for stronger regional cooperation,” said Javier Rodríguez, director of new markets at the Mexico International Fair. “This is a reminder that animal health is a foundation for rural development, fair trade, and public well-being.”
The National Service for Agrifood Health, Safety and Quality (SENASICA) confirmed that larvae from a recent case in Nuevo León were found dead, indicating current treatment protocols are working.
Meanwhile, Brazilian beef imports to Mexico have surged by more than 250%, surpassing 70,000 tons this year. Producers are urging tighter trade controls and tariffs, arguing that the influx creates unfair competition during a national animal health emergency.
