“We have identified additional strains of Shiga-toxin producing E. coli in water and soil samples, but at this time, the samples from the canal water are the only matches to the outbreak strain,” the FDA says.

As of June 27, the CDC reports that 210 people in 36 states have become ill. These people reported becoming ill in the time period of March 13, 2018 to June 6, 2018. And have been 96 hospitalizations and five deaths.

Samples have also been collected from environmental sources in the region, including water, soil, and cow manure, anda analysis of additional samples is still ongoing, and any new matches to the outbreak strain will be communicated publicly and with industry in the region.

Identification of the outbreak strain in the environment should prove valuable in our analysis of potential routes of contamination, and we are continuing our investigation in an effort to learn more about how the outbreak strain could have entered the water and ways that this water could have come into contact with and contaminated romaine lettuce in the region.

The traceback investigation indicates that the illnesses associated with this outbreak cannot be explained by a single grower, harvester, processor, or distributor. While traceback continues, the FDA will focus on trying to identify factors that contributed to contamination of romaine across multiple supply chains.  

The agency is examining all possibilities, including that contamination may have occurred at any point along the growing, harvesting, packaging, and distribution chain before reaching consumers.

The FDA says the current outbreak is not related to a recent multistate outbreak of E. coli O157:H7 infections from November to December 2017 linked to leafy greens consumption. People in the previous outbreak were infected with a different DNA fingerprint of E. coli O157:H7 bacteria.