Mexico insists no proof its lettuce caused U.S. cyclosporiasis outbreak

Mexico's government is maintaining its stance that there is no conclusive evidence linking lettuce produced in the central state of Guanajuato to the cyclosporiasis outbreak in the United States. U.S. health authorities, however, continue to point to an epidemiological association with the product.

Federal Commissioner for Protection against Sanitary Risks, Víctor Hugo Borja, explained that the U.S. investigation stemmed from interviews with infected individuals by the Centers for Disease Control and Prevention (CDC). Many reported consuming processed lettuce from fast-food restaurants. This led the U.S. Food and Drug Administration (FDA) to trace the supply chain to a Taylor Farms plant in Guanajuato, subsequently notifying Mexico.

"What they report to us are hypotheses, not confirmed matters," Borja stated during a presidential press conference. Following the alert, Mexican authorities inspected the plant and analyzed five samples of whole lettuce, five of processed product, and water from the facilities. "We found that all were negative. Thus, the hypothesis is not confirmed by these laboratory study results," Borja added.

Despite the negative findings, Borja acknowledged that the investigation remains open, noting, "The hypothesis is still maintained and the direct source is not confirmed." He reiterated, "The Mexican origin is still not proven." Taylor Farms has preemptively halted operations at the plant pending a risk analysis, according to the head of Cofepris.

The cyclosporiasis outbreak has led to thousands of infections and two deaths in the U.S., though health authorities clarified the victims had pre-existing conditions and the parasitic infection was a contributing factor. Mexico is also investigating other foodborne illness links, including potential connections between Mexican serrano peppers and a salmonella outbreak in the U.S., and cases of cyclosporiasis in travelers returning from Quintana Roo.