FDA Releases Findings of Romaine Lettuce Sampling Project from Arizona Growing Area

In an effort to prioritize the safety of leafy greens, FDA has released its findings of a sampling report it conducted on romaine lettuce collected earlier this year from Yuma County, Ariz.

In February 2021, FDA started collecting samples of romaine lettuce from commercial coolers, with plans to sample through the end of the romaine harvest season in the growing region. This was in response to a 2018 multistate E. coli outbreak, which saw 210 infections and five deaths in 36 states.

The agency collected 504 romaine samples and tested the lettuce for Shiga toxin-producing E. coli (STEC), specifically enterohemorrhagic E coli. (EHEC), and Salmonella spp. Each sample consisted of 10 subsamples, and each subsample was made up of at least 300 grams of romaine lettuce (whole heads, hearts, or individual leaves).

The investigation discovered E. coli O130:H11 in one sample. The isolate was found to be moderate to high-risk, though the FDA report noted that it wasn’t linked to any known human illnesses, and no product ever reached consumers. Furthermore, FDA investigated the farm where the sample came from and identified possible sources and routes of contamination, and just one of these total 24 samples yielded another strain found on the outer leaves of romaine lettuce. The strain was further characterized as low risk to human health, and FDA’s analysis indicated the strain was not linked with any past known foodborne illness outbreaks.

FDA says it continues to make the safety of leafy greens a priority, an initiative that includes its Leafy Greens STEC Action Plan (LGAP), which features public health approaches related to response and prevention, and addressing knowledge gaps. “Romaine lettuce and other leafy greens are among the most widely consumed vegetables in the United States and are an important part of a healthy diet,” the report says. “The agency is working on several fronts to help prevent microbial contamination of leafy greens and to prevent outbreaks of foodborne illness. The FDA continues to collaborate with industry, states, academia, and other stakeholders through activities outlined in the LGAP to address this important public health issue.”