Why what’s lurking in leafy greens can make you seriously sick – keyt gas turbine


A total of 121 people from 25 states have become ill from E. coli contamination linked to romaine lettuce between March 13 and April 21, the US Centers for Disease Control and Prevention reported Wednesday. There has been one death in California resulting from an E. coli infection.

"Leafy greens, such as lettuce, can become contaminated in the field by soil, contaminated water, animals or improperly composted manure," said Jeff Farber, director of the Canadian Research Institute for Food Safety and a professor at University of Guelph in Ontario. "Lettuce can also be contaminated by bacteria during and after harvest from handling, storing and transporting the produce."

In the current outbreak, 52 of the 102 patients who have been interviewed by public health officials have been hospitalized, including 14 who developed a type of kidney failure called hemolytic uremic syndrome. This 51% hospitalization rate is higher than the 30% typically seen in E. coli outbreaks.

The strain of bacteria involved in the outbreak is Shiga toxin-producing Escherichia coli O157:H7. This "tends to cause more severe illness, which may explain why there is a high hospitalization rate," the CDC said in its outbreak investigation update.

Between 1998 and 2016, there were 45 outbreaks associated with Shiga toxin-producing E. coli in leafy vegetables reported in the United States, CDC spokeswoman Brittany Behm said. The new one is the largest outbreak of its kind since a deadly E. coli outbreak in 2006 that was linked to spinach.

In the new outbreak, the investigation revealed that several people in an Alaska correctional facility who became sick had consumed romaine lettuce sourced from Harrison Farms of Yuma, Arizona. The agency has not determined where in the supply chain contamination occurred.

Rachel Noble, a biologist and professor in the Department of Environmental Sciences and Engineering at the University of North Carolina at Chapel Hill, explained that because "lettuce is grown very close to the ground," rain and the process of irrigation allow dirt and silt to "jump up onto the lettuce," leading to contamination.

"Any commercially grown lettuce product will be put through some basic wash step before it’s sold," Noble explained. The series of baths and tumblers is not a thorough cleaning, however; it’s just enough that the end product is "appealing to the customer."

Still, consumers have "a role to play," he said, by paying attention to food recalls and asking questions when they are unsure of quality or safety of a food product. They also need to know "that ‘best before’ or ‘use by’ dates are only based on quality and not safety."

Generally, Farber recommends washing your hands thoroughly with warm water and soap for at least 20 seconds before and after handling lettuce and then washing lettuce thoroughly under fresh, cool running water. Wilted or brown leaves should be discarded along with the outer lettuce layer, he said.

The CDC also offers recommendations for consumers to avoid becoming infected with a harmful strain of E. coli. Generally, the agency advises using proper handwashing and kitchen sanitation when preparing food; cooking meat at proper temperatures; avoiding raw milk, unpasteurized dairy products and juices; and not swallowing water when swimming.