You are probably thinking that is an odd title unless you have been monitoring the Blue Bell ice cream recall in recent weeks. Blue Bell hit the news back in mid-March when they recalled ice cream products from one of their production lines owing to contamination with Listeria monocytogenes (Lm). Flashing forward to the end of April, Blue Bell has recalled all of its products
currently in the market made at all of its facilities due to potential contamination with Lm. It turns out that arriving at where this case is today has been the result of a long and complex, multi-state outbreak investigation that may reach back as far as 2010. There are currently 10 people sickened by this incident across four states (Arizona, Kansas, Oklahoma, and Texas) with three deaths (all in Kansas). All of the victims were elderly and had other underlying health issues and were hospitalized before developing listeriosis.
While this is a tragedy that we can all relate to, you may still be asking, what does this have to do with produce? A few more pertinent facts might help: When public health officials assess the risk a specific food might present if contaminated with Lm, they look at whether that food would support the growth of Lm (if it were present), the contamination level or “dose,” how the food might be used (cooked, eaten fresh, etc.), and the demographic of the people likely to consume the food. Ice cream would not be considered a food that would support the growth of Lm since it is frozen. So, I guess it might be logical to jump to the conclusion that the dose level must have been very high to make these folks ill and to cause death. From everything I have heard, the dose level in the ice cream is very low, well short of the 100 CFU/g Codex tolerance that we have all come to know. Further, this case represents a unique research opportunity for the U.S. Food and Drug Administration (FDA) as they have an abundance of samples to test; it is a palletized, frozen product that they can work through and analyze to determine the dose levels and characterize the Lm strains that are present. Since the victims were all in the hospital to begin with, FDA can also determine how much of this ice cream was consumed and determine each patient’s exposure to the pathogen. So, you are still not seeing it, are you?
Well, in the last year, Lm issues associated with stone fruits and apples have served to fuel produce industry conversations around FDA’s “zero tolerance” approach to Lm —i.e., FDA considers any level of Lm to be an adulteration of the food and therefore illegal to be put into commerce. Many point to the Codex tolerance other countries employ, the perception that it takes a high dose of Lm to make people sick, the view that Lm is “everywhere,” and the relatively low frequency of listeriosis and wish to see a revised policy somewhere north of zero. The Blue Bell ice cream case though guts that line of thinking, or at least may make folks re-think that position. While there is much work to be done to fully understand this case; one thing is clear — people died eating a food that did not support Lm growth and apparently the dose levels were very low. I guess it could be said that the victims were all elderly or already had underlying health issues, and from what I understand that is true. A young, strong adult with a vital immune system could very likely consume foods with low levels of Lm and be just fine; that’s probably why we just don’t see more outbreaks with this insidious pathogen and why some public health officials think that Lm-related illnesses are under-reported overall. However, a growing number of people have less than effective immune systems due to age or disease or other chronic factors and may therefore be more susceptible to certain Lm strains than originally thought. That alone is enough to make FDA very cautious about changing their “zero-tolerance” policy anytime soon. Remember their principal objective is to protect public health.
So if the regulatory policy is not likely to change anytime soon, we are left with combating the risk of product contamination with Lm at the source. Current thinking is that Lm becomes a cross contamination risk when it is permitted to take up residence in packinghouses and processing plants. In other words, Lm comes in on the raw product or field debris and contaminates packing or processing equipment, floors and drains. If this environment is not cleaned properly and sanitized effectively on a regular and frequent basis, Lm can take up residence — for example, become established in the nooks and crannies of your equipment or in the drainage systems of your facility, grow or multiply to significant levels and then contaminate contact surfaces and get transferred to product as it is sorted, washed or packed. An effective and verifiable sanitation program is one of the best tools we have to manage this potential risk. However, it is more than just routine cleaning and sanitation; it requires proper equipment design, careful process management, proper product temperature and moisture control, etc.
The key is not to get overwhelmed with the challenge. Get started. Evaluate your process —where are the hard-to-clean places in your operation and could they harbor Lm? Determine how effective your cleaning and sanitation processes currently are. Do you have a written sanitation program in place and is your sanitation crew properly trained? How are you verifying that your cleaning and sanitation activities are effective? What could you do better? What pieces of equipment are particularly hard to clean? How might you change that design when you upgrade the equipment the next time or buy a new piece of equipment as you grow? Better yet, are there any modifications you might make on existing equipment to make them easier to clean effectively? The common terminology is to seek out Lm and destroy it. It is not easy, but it is doable. We can learn a great deal from the meat industry and all they went through over a decade ago when they faced the Lm challenge.
The good news is, many in our industry have been addressing these questions for years and understand that Lm is likely never going to be a static question, the scientific knowledge on Lm and how it persists in our production environments and causes illness in humans will continue to expand and with that understanding, we will be better equipped to develop the tools our industry can employee to manage the risks.
Who thought ice cream could be a catalyst for change in the produce industry?