The most widespread E. coli outbreak in the last 13 years appears to have been caused by bad water, according to the CDC.
Thursday night updates from the Centers for Disease Control and Prevention and the Food & Drug Administration all but officially declared the romaine lettuce E. coli outbreak over after 210 illnesses and five deaths in 36 states. But, both organizations said in their May 16 updates that the tainted romaine lettuce from the Yuma, Arizona, region should've been out of circulation.
So, aside from a final counting of the sick, only the how and why remained for the CDC and FDA to tell the public. And that appears to come down to the water.
"CDC laboratory testing identified the outbreak strain of E. coli O157:H7 in water samples taken from a canal in the Yuma growing region," the CDC said Thursday. "(Whole genome sequencing) showed that the E. Coli O157:H7 found in the canal water is closely related genetically to the E. coli O157:H7 from ill people. Laboratory testing for other environmental samples is continuing. FDA is continuing to investigate to learn more about how the E. coli bacteria could have entered the water and ways this water could have contaminated romaine lettuce in the region."