USDA specialists arrived in Mexico to evaluate screwworm eradication efforts after a month-long suspension of Mexican cattle exports. Only 281 cases remain active.
Over a month after the United States suspended cattle imports from Mexico due to a resurgence of screwworm cases, agricultural officials from both countries are working to resolve the issue and restart trade. Julio Berdegué, Mexico’s Secretary of Agriculture and Rural Development, announced this week that a team of experts from the U.S. Department of Agriculture (USDA) has arrived in Mexico to evaluate the country’s progress in controlling the parasite.
The USDA visit is a key step in determining whether sanitary conditions are sufficient to lift the ban, which has been in place since May 11. This marks the second time exports have been halted due to the pest since the first screwworm case reappeared in Mexico in November 2023.
On Monday, Berdegué shared on social media that USDA specialists will accompany Mexican officials in field inspections and assessments. The outcome of these evaluations will influence whether the U.S. government allows Mexican cattle back into American markets. As of June 11, only 281 screwworm cases remain active out of the 2,095 that have been registered since the outbreak began.
The Mexican government’s response has been part of a coordinated binational strategy, which includes extensive surveillance, treatment of infected livestock, and fly eradication programs. According to the National Service of Health, Safety, and Agrifood Quality (SENASICA), 1,814 of the confirmed cases have already been neutralized.
Last week, Berdegué reiterated Mexico’s commitment to eradicating the pest and protecting the nation’s cattle industry. On June 2, he hosted USDA representatives in Mexico City for meetings focused on strengthening joint efforts and accelerating progress toward full containment.
This coordinated response also includes plans for long-term prevention. During a virtual meeting on May 27 between Berdegué and USDA Under Secretary Brooke Rollins, the two officials discussed the next steps toward lifting the ban and improving biosecurity.
One key result of that meeting was the approval of U.S. support for the construction of a new sterile screwworm fly production plant in Chiapas. The facility, expected to cost $21 million, will bolster Mexico’s ability to release sterile male flies—a technique proven to disrupt the breeding cycle of the parasite. This proposal had been on the table since the health emergency began but gained momentum with the USDA’s backing.
Screwworms, the larvae of the Cochliomyia hominivorax fly, pose a major threat to livestock. They burrow into wounds of warm-blooded animals, feeding on tissue and potentially causing severe infection or death if left untreated. The pest was once endemic to North America but had been eradicated through joint U.S.-Mexico efforts decades ago. Its reappearance late last year alarmed health and trade officials on both sides of the border.
The impact of the export suspension has been significant. Mexico is one of the leading suppliers of cattle to the United States, and the indefinite halt in trade has disrupted business for ranchers and exporters, particularly in northern states like Chihuahua, Sonora, and Coahuila.
While no date has been set for resuming exports, officials remain cautiously optimistic. If the USDA inspectors verify that sanitary protocols are being followed and case numbers continue to drop, a partial reopening could be possible in the coming weeks.
In the meantime, Mexico continues to roll out containment strategies, working closely with U.S. counterparts to ensure the pest is fully eradicated and future outbreaks are prevented.
USDA specialists arrived in Mexico to evaluate screwworm eradication efforts after a month-long suspension of Mexican cattle exports. Only 281 cases . . .
