2006 North American E. Coli O157:H7 Outbreak in Spinach - Cause

Cause

The outbreak was traced to organic bagged fresh spinach—sold as conventional produce—grown on a 50-acre (200,000 m2) farm in San Benito County, California. Investigators with the Centers for Disease Control initially speculated that the dangerous strain of bacteria, E. coli O157:H7, originated from irrigation water contaminated with cattle feces or from grazing deer.

A follow-up report by the CDC and a joint report by the California Department of Health Services (CDHS) and U.S. FDA concluded that the probable source of the outbreak was Paicines Ranch, an Angus cattle ranch that had leased land to spinach grower Mission Organics. The report found 26 samples of E. coli “indistinguishable from the outbreak strain” in water and cattle manure on the San Benito County ranch, some within a mile from the tainted spinach fields. Although officials could not definitively say how the spinach became contaminated, both reports named the presence of wild pigs on the ranch and the proximity of surface waterways to irrigation wells as "potential environmental risk factors." The reports also noted that flaws in the spinach producer's transportation and processing systems could have further spread contamination. Paicines Ranch is not under investigation for its alleged role in the outbreak.

Soon after the reports were released, California's farm industry announced that it will adopt a set of "good agricultural practices" to reduce the risk of E. coli contamination for leafy green vegetables. Those participating in the voluntary program will be eligible for product seal of approval.

Two companies in California voluntarily recalled spinach and spinach-containing products: Natural Selection Foods LLC, based in San Juan Bautista, and River Ranch Fresh Foods. Natural Selection brands include Natural Selection Foods, Pride of San Juan, Earthbound Farm, Bellissima, Dole, Rave Spinach, Emeril, Sysco, O Organic, Fresh Point, River Ranch, Superior, Nature's Basket, Pro-Mark, Compliments, Trader Joe's, Jansal Valley, Cheney Brothers, D'Arrigo Brothers, Green Harvest, Mann, Mills Family Farm, Premium Fresh, Snoboy, The Farmer's Market, Tanimura & Antle, President's Choice, Cross Valley, and Riverside Farms. Affected brands from River Ranch include Hy-Vee, Farmer's Market and Fresh and Easy. Later, a third company, RLB Food Distributors, issued a multiple East Coast states recall of spinach-containing salad products for possible E. coli contamination. Natural Selection Foods announced on September 18, 2006 that its organic produce had been cleared of contamination by an independent agency, but did not lift the recalls on any of its organic brands. On September 22, Earthbound Farm announced that the FDA and the CDHS confirmed that its organic spinach had not been contaminated with E. coli.