The U.S. Food and Drug Administration (FDA) is investigating a farm in the Yuma, Ariz., winter vegetable producing area as part of its traceback investigation into the source of a Escherichia coli (E. coli) 0145 outbreak in romaine lettuce that made 19 people ill in three states.

The FDA is trying to determine if the E. coli came from the farm, processor, or another step in the food chain. The lettuce in question was shipped in bulk from the desert and processed somewhere besides Arizona, according to Kurt Nolte, University of Arizona Cooperative Extension director for Yuma County.

“Nothing has been confirmed on the source of the contamination,” said Kurt Nolte, University of Arizona Cooperative Extension director, Yuma County, Ariz. “The FDA has not confirmed that the contamination source is a Yuma farm.”

On May 6, the FDA confirmed E. coli 0145 was found in romaine lettuce which possibly caused illness in Michigan, Ohio and New York.

New York-state public health laboratory in Albany confirmed E. coli 0145 in an unopened bag of Freshway Foods-shredded romaine lettuce.

Freshway Foods, a processor in Sidney, Ohio, voluntarily recalled products containing romaine lettuce with a use-by date of May 12 or earlier. The products were sold under the Freshway and Imperial Sysco brands in 23 states.

Freshway says romaine lettuce from the company is sold for food service outlets, wholesale, and in-store retail salad bars and delis. Freshway does not produce pre-packaged greens for supermarket sales.

Vaughan Foods of Moore, Okla., a supplier of processed and packaged lettuce for food service, received lettuce from the same Yuma farm. The company is recalling romaine lettuce with use-by dates of May 9 and May 10. Vaughan’s recalled lettuce was sold to restaurants and food service facilities, not purchased at retail by consumers.

Nolte says the recalled Freshway romaine lettuce package suggests the product was harvested in mid-to late April. The romaine lettuce season generally ends in the Yuma area in early April.

“That would be extremely on the outermost production time in Yuma,” Nolte told The Yuma Sun. “That’s past our prime season. It becomes too hot.”

Lettuce is generally cut in the morning, cooled in the afternoon, and placed on a truck that evening for distribution.

About 85 percent of the U.S. winter supply of vegetables for salads is grown in the Yuma area. The winter vegetable season generally wraps up by mid April.

The Western leafy green industry operates under detailed, science-based leafy green production practices designed to bolster food safety. The leafy greens marketing agreement (LGMA), an agricultural industry-developed program, was implemented in California in 2007, in response to an E. coli 0157:H7 outbreak on a California spinach farm.

The 100 LGMA signatory handlers must purchase leafy greens grown under the strict production practices. The handlers represent about 99 percent of the leafy greens grown in California.

A similar LGMA program was implemented Arizona in 2008.

If the E. coli contamination is traced back to a farm, agricultural leaders are willing to update farming practices to reduce E. coli outbreaks.

Arnott Duncan, a Litchfield Park, Ariz., leafy greens grower and member of the Arizona LGMA committee, said, “I hope the source of the contamination is found. If the problem is traced back to agriculture, the LGMA offers us a vehicle to immediately pursue corrective actions.”

Food contamination can occur anywhere in the food chain, Duncan says, from not thoroughly washing hands to handling other contaminated products.

“The Arizona LGMA is a message to the general public that agriculture will do everything possible to modify the guidelines if needed to ensure public safety,” Nolte said.

The E. coli issue has not impacted the demand and price for summer vegetable sales at Fresh Kist Produce, a grower-packer-shipper in Guadalupe, Calif., in Santa Barbara County.

“So far we have not experienced any repercussions,” says Fresh Kist salesman Craig Smithback. “I just packed up and sold a load to a processor back east today that I normally don’t get an order from. That tells me that either there is no change or the supply is so short that they need it anyway to cover their orders.”

Smithback said prices are holding steady.

This could be the first time E. coli 0145 has been found in U.S.-grown leafy greens. Food-related E. coli outbreaks in the past have been mostly linked to the E. coli 0157:H7 strain.

Trevor Suslow, University of California Cooperative Extension research specialist, said, “E. coli 0157:H7 is the classic type of E. coli that can cause serious illness and potential death.”

Suslow studies microbial food safety in fresh produce.

E. coli 0145 is well recognized as a type that can cause these kinds of clinical symptoms and illness; however it is not commonly associated with food,” Suslow said. “The 0145 and 0157:H7 strains are among the most aggressive and more virulent types of E. coli.”

On a scale from 1 to 10, Shoana Anderson, Office of Infectious Diseases, Arizona Department of Health Services, gives the 0157:H7 and 0145 strains an 8 for toxicity. Both strains produce the shiga toxin which can result in bloody diarrhea and even death.

Children, the elderly, and those who are immune compromised face the worst danger from the E. coli strains, Anderson says.

email: cblake@farmpress.com