The Cantaloupe Crisis: What’s Next?

Fruit linked to unprecedented listeriosis outbreak sparks renewed efforts to ensure produce safety

In September, when Steve Patricio learned of the Listeria outbreak traced to cantaloupes from a farm in Colorado—an outbreak that killed 29 people as of Nov. 9, sickened dozens, and caused one miscarriage—his mind immediately raced back two decades to a similar outbreak.

In the summer of 1991, more than 400 people in the Western United States developed Salmonella after eating tainted cantaloupes. In that case, the original source of the outbreak was never identified, although many suspected a grower in West Texas, who in turn pointed the finger at Mexican farms. No one died in that outbreak, but the cantaloupe industry took an enormous hit—just as it’s doing now.

“At the peak of the outbreak, demand for cantaloupes decreased by 60%,” said Patricio, chair of the California Cantaloupe Advisory Board. “Retail buyers believe that consumers are still walking past the product, and probably for good reason. There’s no way to adequately apologize for or explain (29) deaths and a hundred-plus illnesses. We’ll deal with the fallout from this for a generation.”

On Oct. 19, the FDA released a report indicating that the outbreak—the first-ever listeriosis outbreak associated with fresh, whole cantaloupe—was an outlier incident, primarily attributable to unsanitary conditions in the packing facility at Colorado grower Jensen Farms. The report found:

• A truck used to haul culled cantaloupe to a cattle operation was parked adjacent to the packing facility and could have introduced contamination into the facility;
• The packing facility’s design allowed water to pool on the floor near equipment and employee walkways;
• The packing facility floor was constructed in a manner that made it difficult to clean;
• The packing equipment was not easily cleaned and sanitized; washing and drying equipment used for cantaloupe packing had previously been used for post-harvest handling of another raw agricultural commodity; and
• There was no pre-cooling step to remove field heat from the cantaloupes before cold storage. As the cantaloupes cooled, there may have been condensation that promoted the growth of Listeria monocytogenes.

A third-party auditor had also failed to cite Jensen Farms for any of these conditions in a glowing report after a visit to the facility in August—less than a month before the outbreak began.

But even if you consider Jensen Farms a “bad apple” in the produce trade, the safety of cantaloupes remains a persistent challenge for the industry. “Netted melons like cantaloupe grow on the ground and can come in contact with pathogens in non-composted fertilizer or through handling,” notes a report from the University of Wisconsin. “Unlike other fruits, cantaloupe are not acidic and readily support the growth of pathogens once they are sliced open.”

Craig Wilson, Costco’s vice president of food safety and quality assurance, has been characteristically candid in calling for stricter cantaloupe safety measures. In a late September New York Times article, he called for growers to get more aggressive about pathogen prevention and detection in cantaloupes and said Costco would consider setting standards for how melons are grown, cleaned, and handled.

“We want to move that type of testing to cantaloupe. It seems to make good sense to us, and to the vendors that we talk to, for the supplier to know the microbial quality of the fruit he’s putting into commerce.”

—Craig Wilson, Costco’s vice president of food safety and quality assurance

“Doing the same things that we’ve been doing for the last 10 years and expecting a different outcome isn’t the right thing to do,” he told Food Quality.

So what will Costco be calling for? First, said Wilson, the firm wants a finished-product testing program, much like programs that are now applied to ready-to-eat foods. “We want to move that type of testing to cantaloupe. It seems to make good sense to us, and to the vendors that we talk to, for the supplier to know the microbial quality of the fruit he’s putting into commerce.”