2011 listeria outbreak: U.S. cantaloupe contamination leads to lawsuits, search for detection method
In January, the U.S. House of Representatives Energy and Commerce Committee released a bipartisan staff report that details the findings from the committee’s investigation into the September 2011 listeria outbreak, which was traced to tainted cantaloupes from Colorado’s Jensen Farms. The report suggests potential causes for the outbreak.
According to the Centers for Disease Control and Prevention (CDC), there were 29 reported deaths from last fall’s listeria outbreak. As of November, CDC reported 139 people with severe illnesses.
Last September, CDC traced the listeria to tainted cantaloupes from Colorado’s Jensen Farms. The outbreak led to national attention and a widespread drop in cantaloupe sales across the country, according to FDA, USDA and numerous news agencies.
“I’ve had several customers ask me about cantaloupes every day,” said Justin Weaver, the produce manager at Village Foods in Bryan, Texas. “People just aren’t buying cantaloupes.”
In an unannounced visit on Sept. 10, FDA took 39 samples from throughout the Jensen Farms facility. Of the samples, 13 contained listeria contamination. During a second, announced visit, FDA conducted an environmental assessment to identify the factors that led to the contamination. FDA identified multiple potential problems, the report said. These included the lack of a pre-cooling step to remove field heat before the cantaloupes were moved into cold storage; the inability to easily clean the packing facility floor and packing equipment; facility design flaws that allowed water to collect in proximity to equipment and employees walkways; and washing and drying equipment that was originally used on a different agricultural commodity. On October 18, 2011, FDA issued a warning letter to Jensen Farms in relation to these findings.
Cantaloupes in court
Several lawsuits have been filed as a result of the listeria outbreak. The lawsuits are aimed at anyone associated with the growing, distribution and sales of the tainted cantaloupes. Among the retailers dealing with the outbreak’s fallout is Walmart.
“As soon as we were made aware of the listeria outbreak associated with cantaloupes, we immediately worked with health officials and suppliers to determine the source of the contamination,” said Dianna Gee, Walmart spokesperson. “Out of an abundance of caution, we actually began removing Rocky Ford cantaloupes from our stores prior to the official recall. Our food safety team continues to work with our suppliers to ensure we are providing our customers with only cantaloupes sourced from areas health officials deem safe.”
Walmart has been named in a lawsuit filed on behalf of Charles Palmer of Colorado, who became sick during the outbreak after eating a cantaloupe he purchased at a Colorado Walmart store.
“Retailers are going to be left holding the bag,” said Bill Marler, an attorney specializing in food poisoning outbreaks. “The grocery stores and retailers who sold the product, from big-box stores to roadside stands, are going to have to step in and fill the gap.”
Marler has filed suit against Jensen Farms, Frontera Produce and Walmart on behalf of Palmer. It is one of nine such suits brought by Marler’s office. Jensen Farms is one of Frontera Produce’s Colorado growers. Frontera markets Colorado cantaloupes from the Rocky Ford area, where commercial cantaloupe production originated in the United States in 1895.
“In regards to the Walmart lawsuit, we wish Mr. Palmer well and we take claims such as his very seriously,” Gee said.
Marler’s most recent lawsuit names the companies that performed the safety audit at Jensen Farms in July: Primus Labs, a California-based food safety inspection service; and the Texas-based Bio-Food Safety Inc., the company that actually did the inspection under contract from Primus Labs.
The lawsuit was the first filed in New Mexico on behalf of a victim of the listeria outbreak, Florence Wilcox. Wilcox began experiencing symptoms, including fever, chills and weakness, about Sept. 8, after eating contaminated cantaloupes. Wilcox died Sept. 15, Marler said.
Jensen Farms issued a statement saying it was shutting down operations temporarily.
“Our operations will not resume until we are completely satisfied that we have done everything within our power to ensure the safety of our products,” the statement said. “We continue to cooperate fully with the FDA and other government agencies and extend our deepest concerns to any and all members of the public who have been affected by this outbreak.”
Testing response
Detecting pathogens on cantaloupes can be quite difficult, according to FDA. The current technique is the rinse method, which depends on the amount of contaminants present on the cantaloupe, as well as how strong the organisms are attached to the rind. If there is a low level of contamination, which is tightly bound, then the rinse method could produce false negatives.
One possible solution may have come from the University of Idaho, where students Intan Karina, Jo Scholkowfsky, Sarah Reichman and Keith Christopher designed a tester for listeria. In early 2011, with help from faculty advisers, the four students designed a cantaloupe-washing machine that cleans off listeria and other deadly bacteria. It was initially built in response to a salmonella outbreak, also in cantaloupe, and as an entry in a design contest held by the University of Mexico’s Waste-management Education and Research Consortium
The cantaloupe sampler/cleaner device was inspired by the hand-operated golf ball cleaners you see on gold courses, said David Down, the faculty adviser to the student group. The device brushes the cantaloupe while rinsing with a buffer solution to keep the bacteria collected alive for subsequent analysis. The device was tested with a laboratory strain of E. coli, and then a cantaloupe soaked in bacteria-laden “duck pond water” at the contest.
“The device has not been tested with listeria, but there is no reason to believe it would not work just as well on listeria as it does on salmonella and E. coli if the collected sample was analyzed for listeria,” Down said.
There has been no work done on the device since the contest, and future work will require a financial sponsor, Down said. Idaho is not a cantaloupe producing state, and state appropriation funds are not available.
-By Derrek Sigler
