( File photo )

The Food and Drug Administration reported June 28 that its investigation of the multistate outbreak of E. coli O157:H7 infections linked to romaine lettuce may have a connection to irrigation water.

The agency, along with the Centers for Disease Control and state health officials, has been conducting an environmental assessment in the Yuma growing region, according to a news release, to  “further investigate potential sources of contamination linked to this outbreak.”

The FDA said samples have been collected from environmental sources in the region, including water, soil, and cow manure.

 Those evaluations are ongoing.

“To date, CDC analysis of samples taken from canal water in the region has identified the presence of E. coli O157:H7 with the same genetic fingerprint as the outbreak strain,” the FDA said in the release. Investigators found additional strains of Shiga-toxin producing E. coli in water and soil samples, but said, so far, the samples from the canal water are the only matches to the outbreak strain.

The agency said analysis of additional samples is 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 agency said in the release.

The FDA said in the release that suspect product is no longer being harvested or distributed from the Yuma area and is no longer available in stores or restaurants.

As of June 27, the CDC reports that 210 people in 36 states have become ill, with patients reporting illness in the period from March 13 to June 6. There have been 96 hospitalizations and five deaths, the FDA said.