Every day, Mexico loses more than US$11 million due to the suspension of live cattle exports to the United States, a measure imposed by the U.S. Department of Agriculture. Mexico urgently needs to contain the resurgence of the screwworm plague and reverse it, first for its own benefit and then to please the neighboring country’s government.
The way the issue is being dealt with, however, seems to reflect a feeling that Mexico, deep down, does not want to confront the problem, that it would prefer to avoid it, or that it does not care about the inconvenience it causes its northern partners. On April 30, an agreement was reached that the Trump administration felt satisfied its demands, but it only took 11 days for Washington to use its prerogative —recognized in the same document— to close the border for 15 days to Mexican cows, horses, and bison if it deemed the problem was growing. In terms of business days, it only took seven to move the pieces back to square one.
This occurs in a context in which the world continues to seek ways to understand the White House’s trade policy decisions, and in which Mexico, due to its geographical location and extremely close ties to its neighbor, is being particularly affected.
In recent weeks alone, actions such as the imposition of tariffs on steel and aluminum and some Mexican agricultural products; the secretive execution of agreements —with their unilateral and equally hidden implementation— with the criminal faction Los Chapitos, which have a strong and bloody impact on public order; the preemptive actions against high-profile figures, such as the governor of Baja California, which were not promptly reported or even explained; as well as the previously mentioned screwworm restrictions, have sparked a perception that many of these measures are not isolated or independent of each other, and are politically motivated, intended to generate pressure on Mexico.
Hence, there is a growing concern that permeates all sectors of Mexican society, from the social and economic to the political spheres. On these issues, the opposition has overcome its animosity to close ranks with President Sheinbaum.
And that is why the President, perhaps risking an undermining of her already global reputation for maintaining composure and a cool head, hardened her rhetorical tone somewhat on Monday when expressing her disagreement with the “unjust” decision of the United States. She attributed it more to political than health reasons —due to the 2026 U.S. elections— insisting that “there is no subordination, nor can we be immediately responding to everything that is said every day” and reminding anyone who needs to be reminded of it that “Mexico is not anyone’s piñata.”
AGREEMENT AND BELOW THE BELT MEASURES
The screwworm, or New World fly (Cochliomyia hominivorax), is a devastating pest that affects livestock, wildlife, and, in rare cases, humans, causing serious and potentially fatal infections. This disease was eradicated in the United States in the 1960s and in Mexico in the 1970s, thanks to collaborative efforts that included the Sterile Insect Technique, which releases sterile flies to prevent reproduction. However, in recent years, it has reemerged in Central America, with documented cases in Panama, Costa Rica, Nicaragua, Honduras, Guatemala, and, more recently, in southern Mexico, particularly in Chiapas and Tabasco.
On April 30, U.S. Secretary of Agriculture Brooke Rollins announced an agreement with Mexico to resume eradication efforts. Mexico would remove restrictions on U.S. Department of Agriculture aircraft involved in pest control and exempt necessary equipment and inputs, such as sterile flies and aircraft parts, from tariffs. As a result, U.S. ports would remain open for livestock imports.
But on May 11, Secretary Rollins announced the immediate suspension of live livestock imports —cows, horses, and bison—citing the “continued and rapid northward spread” of the screwworm, noting recent detections on remote farms with minimal livestock movement in Oaxaca and Veracruz.
AN ECONOMIC HEMORRAGING FOR MEXICO
The plague has had a direct impact on the Mexican livestock sector, which is crucial for exports and food security. A first suspension began on November 22, 2024, after cases were detected on the southern border. According to a December 15 report by the newspaper El País, weekly losses in Chihuahua amounted to between US$25 million and US$30 million due to the inability to sell 110,000 calves, while in Durango they were estimated at US$7 million—also per week—affecting the export of 5,000 calves.
Furthermore, that report warned that, in the event of a severe outbreak, the cost of eradication could reach US$830 million, and if the plague were to spread to the United States, annual losses could reach US$1 billion, seriously impacting Mexican trade. The measure was lifted on February 1, following the implementation of a pre-export inspection and treatment protocol to prevent the entry of screwworms into the United States.
With the new suspension now in effect —according to Mexican Minister of Agriculture Julio Berdegué—losses are reaching US$11.4 million per day.
For Mexico, it is urgent to halt this economic crisis.
MEASURES TO FIGHT THE SPREAD OF SCREWWORM INFECTIONS
Since June 2024, the Ministry of Agriculture has allocated more than 167 million pesos –US$8.52 million- to strategic actions to prevent, control, and eradicate the pest, allowing the country to maintain its screwworm-free status, acquired in 1991:
*Spray baths with larvicides are being carried out.
*Three inspection points have been established, with mobile units for alternate routes, as part of the sanitary barriers in southern Mexico, especially in Chiapas, Oaxaca, and Veracruz. In addition to larvicide spraying, inspections are carried out to ensure that cattle have been treated, have bathing certificates, and that such documentation is properly certified.
*Electronic imaging-assisted diagnoses are performed, which serve to identify parasites early, allowing for risk mitigation with rapid response.
*To date, 885 million sterile flies have been released since November 30, 2024, in collaboration with the U.S. Animal and Plant Health Inspection Service.
*Guidelines were issued to strengthen biosecurity in production units, control livestock imports from affected countries, and treat animal wounds in a timely manner to prevent infestations.
Furthermore, on Tuesday, Minister Berdegué said that to overcome the logistical problems caused by the flies coming from a plant in Panama (they are then conditioned and released at packaging centers in Tuxtla Gutiérrez and Tapachula, Chiapas), Mexico proposed to the United States the construction of a factory on the border with Guatemala, and is still awaiting a response.
FIFTEEN DAYS TO EVALUATE
“Mexico is doing 100 percent of what we agreed to with the United States,” Berdegué added, and announced that more will be done: “We are going to do a clean sweep from the Gulf of Mexico to the Pacific, off Veracruz, all the way to Oaxaca and southern Guerrero, visiting and inspecting 100% of the farms.”
He said that after the 15-day inspection, the U.S. Department of Agriculture will have to evaluate the progress made.
The risk is that, beyond the strictly technical considerations, political gamesmanship will continue to affect their decision-making. In that case, Mexico will have to repeat more forcefully that it wants to be removed from the U.S. electoral disputes, and the President will have to calculate the tone in which the country can be best heard, even if she needs to be a bit less polite.
Mexican Press Agency is part of ALMA, which is dedicated to news and information about Mexico and Mexicans in the United States and is a fiscally sponsored project of Social Focus, a 501(c)(3) nonprofit organization based in Redwood City, California.
