The deadly infection outbreak of E. coli in Romaine lettuce is over. Once again, the Romaine lettuce you pick up at the store or pile onto your is once again safe to eat.
That’s the good news. But what happened?
How did the lettuce become contaminated in the first place? The answer might be in the water.
An outbreak update issued by the US Centers for Disease Control and Prevention last Thursday says the lettuce was contaminated with a particularly virulent strain of E. coli O157:H7.
It sickened 210 people in 36 states between March 13 and June 6.
Ages of victims ranged from 1 to 88 years of age.
Ninety-six of those folks were sick enough to be hospitalized; 27 of those developed hemolytic uremic syndrome, a type of kidney failure. Five people from four states died. It’s the worst outbreak of E. coli O157:H7 since a 2006 outbreak linked to spinach.
What’s lurking in the greens that may make you seriously sick?
The CDC used a new form DNA fingerprinting called whole genome sequencing to determine that the E. coli bacteria sampled from those who became ill was (genetically) closely related genetically, which allowed researchers to conclude a single source of infection was likely.
The US Food and Drug Administration, the CDC and their state partners, were able to trace the outbreak back to a single growing region: Yuma, Arizona, the “Winter Lettuce Capital of the World.”
But if the water only supplied lettuce fields it may be OK. We.. sort of OK. No. The superb soil deposited by the Colorado River and efficient irrigation mean Yuma grows about $2.5 billion a year from 175 crops, including dates, lemons, and melons. Yuma County says it grows 90% of all leafy greens America eats between the months of November and March.
According to the FDA, the last shipments of lettuce for the season shipped in April, and the shelf life has since expired, therefore the contaminated lettuce is no longer available. (We hope and trust!)
Not Just Lettuce
FDA found that the outbreak couldn’t be traced back to a single grower. It was across multiple supply chains. That led to suspicions that the outbreak might be from a common water source.
The CDC agreed. Samples taken from canal water that irrigated the Yuma growing fields were laced with the same deadly bacteria.
“The E. coli O157:H7 found in the canal water is closely related genetically to the E. coli O157:H7 from ill people,” the CDC said in a final update on the outbreak.
How the E. coli came to be in the canal water is still unknown. “Samples have been collected from environmental sources in the region, including water, soil, and cow manure. Evaluation of these samples is ongoing,” the FDA said in an update.
Interestingly, not all of the people who became sick had actually eaten romaine lettuce. Some had close contact with people who had eaten the infected greens. The CDC reminds everyone to always use safe handling practices with any fruit or vegetable.
“Important steps to take are to cook meat thoroughly, and wash hands after using the restroom or changing diapers, before and after preparing or eating food, and after contact with animals,” advises the CDC.
Ian: AND drink only pure healthy water – not from the same source these studies highlight!