Adding Up Listeria, Cantaloupe and Hot Dogs

The FDA has finally released a report that identified the reasons fresh cantaloupe killed at least 25 in one of the deadliest outbreaks of Listeria monocytogenes we’ve seen. In a nutshell? Poor sanitation.

When the contaminated cantaloupe death toll reached 21, many news sources compared the result to 1998 outbreak of Listeria in hot dogs, and possibly deli meats, made by Sara Lee’s Bil-Mar Foods, a subsidiary of Sara Lee.  The cause of that outbreak? Poor sanitation.

The FDA’s report found the following problem areas in cantaloupe-grower Jensen Farms’ packing and storage facilities:

• 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;
• Facility design allowed for the pooling of water on the packing facility floor adjacent to equipment and employee walkway access to grading stations;
• The packing facility floor was constructed in a manner that was not easily cleanable;
• The packing equipment was not easily cleaned and sanitized;
• washing and drying equipment used for cantaloupe packing was previously used for postharvest handling of another raw agricultural commodity; and
• There was no pre-cooling step to remove field heat from the cantaloupes before cold storage.

The Bil Mar hot dog and deli meat outbreak was traced to condensation problems that led to post-processing product contamination. The processed-meat industry is fully alerted to the dangers of Listeria.

However, I see plenty of internet “experts” commenting on how these things wouldn’t happen if it were a “family farm” or “organic” or “products from a farmers market.” To co-opt a popular You Tube meme, “Listeria monocytogenes don’t care.”

As anyone familiar with Food Pathogens 101 knows, Listeria loves damp chilly places with plenty of available moisture. So if you have an at-risk facility, vigilance is essential. Don’t be complacent. And don’t think it can’t happen to you. 

“While outbreak investigations provide valuable information about potential modes of L. monocytogenes transmission, they do not always identify the contaminated food source. Thus, the full range of potential food vehicles of L. monocytogenes has most likely not been identified, and the assessment of risks among different foods cannot be based solely on the current epidemiological record.” (From FDA’s and FSIS’s 2003 “Quantitative Assessment of Relative Risk to Public Health from Foodborne Listeria monocytogenes Among Selected Categories of Ready-to-Eat Foods.”)

-Lynn A. Kuntz