Nine new cases of infection withE. coli O157:H7 have been reported, bringing the total number of people sickened in the U.S. between October 5 and November 18, 2018 to 52, theCDC reported in a food safety alert issued on December 6. Nineteen people have been hospitalized, including two who developed hemolytic uremic syndrome, a type of kidney failure. No deaths have been reported. CDC added that illnesses occurring after November 14 might not yet be reported, as it takes an average of 14 to 21 days between when a person becomes ill and when the illness is reported.

The CDC reports that epidemiologic and traceback evidence suggests that romaine lettuce harvested from the Central Coastal growing regions of northern and central California is a likely source of the outbreak. Specific California counties identified by the FDA in the traceback investigation are Monterey, San Benito, San Luis Obispo, Santa Barbara, Santa Cruz, and Ventura.

Consumers are advised not to eat romaine lettuce harvested from these regions. As WholeFoods Magazinepreviously reported, hydroponically or greenhouse-grown romaine has not been linked to the outbreak. No common grower, supplier, distributor, or brand of romaine lettuce has been identified, though the investigation is ongoing.