A recent romaine lettuce E. coli outbreak that killed five people can be traced to infected water canals in Arizona, according to officials with the Centers for Disease Control and Prevention.

In its final report released Thursday, the CDC said the largest E. coli outbreak in more than a decade, which began on April 10, "appears to be over."

A reported 210 people across 36 states became ill, including 96 who required hospitalization. Twenty-seven people developed kidney failure and five people died: two in Minnesota, and one person each in Arkansas, California and New York.

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State and federal health officials previously traced the outbreak to Arizona's Yuma Valley growing region. The CDC conducted an environmental assessment of soil, water and manure in the area and traced the outbreak to a nearby canal.

Officials say there is no longer any risk associated with the consumption of romaine lettuce. According to the Federal Department of Agriculture, the final shipments of romaine lettuce from the Yuma growing region were made on April 16.

"Contaminated lettuce that made people sick in this outbreak should no longer be available," the CDC noted.

E. coli illnesses can typically be traced to beef, so it is likely the bacteria were introduced to the water from cattle farms located upstream on the irrigation canal.

The report notes that the FDA is "continuing to investigate the outbreak to learn more about how the E. coli bacteria could have entered the water and ways this water could have contaminated romaine lettuce."

Escherichia coli is a collection of bacteria found in "the environment, foods and intestines of people and animals," according to the CDC. While the bacteria are typically harmless, some varieties can cause diarrhea, severe infections, including pneumonia, and even death, the CDC added.