US lettuce outbreak highlights climate risk to food imports
A record parasitic outbreak in the US linked to Mexican lettuce underscores the growing threat that rising global temperatures pose to fresh produce supply chains.
US federal health officials have identified shredded iceberg lettuce from Mexico as the source of a record-breaking parasitic outbreak at Taco Bell locations across five American states. The Centers for Disease Control and Prevention confirmed the link late Thursday, warning consumers in Indiana, Kentucky, Michigan, Ohio and West Virginia to avoid the affected product.
Taco Bell stated it had “voluntarily and temporarily removed limited ingredients at select restaurants as a precautionary measure.” The fast-food chain has since committed to stopping all use of lettuce from the specific supplier identified by the Food and Drug Administration’s traceback investigation.
“FDA is working with the supplier of iceberg lettuce to determine if potentially contaminated shredded iceberg lettuce remains on the market,” including in other states, the CDC said. Federal authorities did not name the company involved.
While geographically contained to the US, the outbreak is part of a worrying trend with direct implications for European food supply chains. More than 30 US states have reported cyclospora infections this year, surpassing the previous record of roughly 4,700 cases set in 2019.
Experts attribute the rising number of cases to the climate crisis and better detection methods. Cyclospora is a microscopic parasite that infects the bowels and spreads when produce is exposed to feces-contaminated irrigation water. According to the CDC, it commonly causes watery diarrhea “with frequent and sometimes explosive bowel movements”, though the illness is rarely life-threatening and typically treated with antibiotics.
Cyclosporiasis is less common than foodborne illnesses caused by germs like salmonella and E coli. For years, few US outbreaks were reported because standard tests did not screen for the parasite, but cases started rising about a decade ago. A notable spike occurred in 2018 and 2019, with outbreaks now tending to happen in late spring and summer.
For European businesses sourcing fresh produce from warmer climates, the US outbreak illustrates a known supply chain vulnerability. Experts link the rising prevalence of this heat-loving parasite directly to the climate crisis. As global temperatures rise, the environmental conditions that allow cyclospora to contaminate agricultural water supplies are expanding.
