Over 7,100 people in Michigan have been sickened by an outbreak of cyclosporiasis, likely caused by contaminated iceberg lettuce.

A recent outbreak of cyclosporiasis in the US has sickened over 7,100 people in Michigan, with iceberg lettuce supplied by Taylor Farms being the likely cause. Leafy greens are frequently implicated in foodborne illness cases, with several outbreaks reported in recent years.

Frequency of Outbreaks

There have been several instances of foodborne illness linked to leafy greens in recent years. In 2022, a multistate E. coli outbreak was tied to romaine served on Wendy's sandwiches, and 173 cases of norovirus were linked to Illinois eatery D.C. Cobb's. In 2021, BrightFarms recalled packaged salad greens sold in several states after 31 people got Salmonella. In 2019, 167 people were infected with E. Coli after eating romaine harvested from the Salinas Valley region in California.

Reasons for Contamination

One reason lettuce is a major source of foodborne illness is that many people eat it. Lettuce is the second-most consumed vegetable in the US, and ready-to-eat salads and blends of spring mix pose a particularly acute risk because they contain multiple types of leafy greens from different farms and locations. How lettuce is grown can also expose it to pathogens, with irrigation with untreated surface water being a common source of contamination. The texture of lettuce, with its many crevices and folds, also makes it prone to spreading disease.