Specifically, the FDA has identified Harrison Farms of Yuma, Arizona, as the grower and sole source of the whole-head romaine lettuce that sickened several people in an Alaska correctional facility, but has not determined where in the supply chain the contamination occurred. 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 the Alaska correctional facility where it was served.

All of the lettuce in question from Harrison Farms was harvested during March 5-16 and is past its 21-day shelf life. Because the growing season in the Yuma region is at its end, the farm is not growing any lettuce at this time.

“We are working to identify multiple distribution channels that can explain the entirety of the nation-wide outbreak and are tracing back from multiple groupings of ill people located in diverse geographic areas,” the FDA says.

Most of the illnesses in this outbreak are not linked to romaine lettuce from this farm though. The agency is investigating dozens of other fields as potential sources of the chopped romaine lettuce and will share information as it becomes available.

To date, the FDA also has no evidence that other types of lettuce, or romaine lettuce grown outside of the Yuma growing region, are involved in this outbreak.

The CDC reports that 98 people in 22 states have become ill. These people reported becoming ill in between March 13, 2018 to April 20, 2018, and Sixty-four (96 percent) of 67 people interviewed reported eating romaine lettuce in the week before their illness started.

Most people reported eating a salad at a restaurant, and romaine lettuce was the only common ingredient identified among the salads eaten. The restaurants reported using bagged, chopped romaine lettuce to make salads. However, traceback does not indicate that Harrison Farms is the source of the chopped romaine that sickened these people. The FDA is continuing to investigate the source of the chopped romaine lettuce that caused these illnesses and has identified dozens of other fields as possible sources.

The most recent illness started on April 20, 2018. Illnesses that occurred in the last two to three weeks might not yet be reported because of the time between when a person becomes ill with E. coli and when the illness is reported to CDC.

Consumers who have symptoms of STEC infection should contact their health care provider to report their symptoms and receive care. Although many infections resolve in 5-7 days, they can result in serious illness, including a potentially serious condition called hemolytic uremic syndrome.

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.