Report: Iceberg lettuce was correlated with cyclosporiasis in Michigan

Key Points:

• Michigan experienced its largest-ever cyclosporiasis outbreak, with 14,510 cases reported as of August 27, linked primarily to iceberg lettuce and consumption at Taco Bell.
• A study published in NEJM Evidence found that nearly 70% of interviewed patients consumed food from a single restaurant chain, confirmed to be Taco Bell, and 89.5% of those who ate Taco Bell items reported consuming iceberg lettuce.
• The Centers for Disease Control and Prevention identified contaminated shredded iceberg lettuce served at some Taco Bell locations as a source, leading to a voluntary recall by supplier Taylor Fresh Foods of iceberg lettuce grown in central Mexico.
• Michigan health officials also found that exposure to iceberg lettuce was associated with illness even among those who did not eat at Taco Bell, though they caution that correlation does not prove causation.
• The outbreak showed two peaks in illness cases, suggesting either two separate contaminated batches of produce or staggered distribution of a single contaminated lot, prompting early public health interventions and warnings.