Small Plant News: Volume 6, Number 9
Listeria monocytogenes and Deli Slicers
By Jeff Tarrant, Commander, U.S. Public Health Service
Commonly used in retail delicatessens, food service, and manufacturing establishments, deli slicers are often difficult to clean and properly sanitize. Recent foodborne illness outbreaks in the United States and Canada involving Listeria monocytogenes (Lm) have been associated with the build-up of food particles and microorganisms on deli slicers. Although the number of people who become ill from Lm is relatively small, this bacterium is disproportionately responsible for fatalities from foodborne illness. The Centers for Disease Control and Prevention estimates that Lm causes 1,600 illnesses, 1,400 hospitalizations, and 260 deaths annually in the United States. CDC estimates that this bacterium is the third leading cause of death from foodborne illness, and 16 percent of those ill die from their infections.
The Foodborne Diseases Active Surveillance Network (FoodNet), a collaboration of the Centers for Disease Control and Prevention (CDC), 10 State health departments, the USDA Food Safety and Inspection Service (FSIS), and the U.S. Food and Drug Administration (FDA), tracks infections with several pathogens transmitted commonly by food, generating data and information that provide a foundation for food safety policy and prevention efforts. The surveillance data allows for the calculation of a case fatality rate for each pathogen, which is the number of deaths caused by a specified disease compared to the
number of diagnosed cases of that disease. Case fatality rates are calculated by dividing the number of deaths by the number of laboratory confirmed infections and multiplying by 100. As you can see from the graph, Lm had the highest case fatality rate in 2011.
Older adults are at the highest risk of developing listeriosis, which is invasive Lm infection, which can result in septicemia, meningitis, and death. Those who are immunocomropmised, due to chronic disease or medical treatment, can have similar outcomes as a result of infection. The effect of Lm on pregnant women and their fetuses is also of great concern. According to the CDC, pregnant women are about 13 times more likely than the general population to contract listeriosis, the illness caused by Lm. A pregnant woman’s illness often consists of mild, flu-like symptoms, however, the bacteria can be passed to a fetus through the placenta even if the mother is not showing signs of illness. This can lead to premature delivery, miscarriage, stillbirth, or serious health problems for the newborn. Approximately 17 percent of listeriosis occurs during pregnancy.
Lm is a hardy bacterium that is salt-tolerant, can grow at low temperature with or without oxygen, and is persistent in food manufacturing environments. Adding to the challenge, Lm can survive in the environment, including food manufacturing and retail environments, for long periods of time and under severe temperature conditions. For example, in 1989, an Lm strain was isolated from a single case of human listeriosis caused by the consumption of processed meat. Eleven years later, the same strain isolated from sliced turkey produced by the same processing plant was implicated in a listeriosis outbreak.
According to the U.S. Department of Agriculture’s FSIS, an estimated 83 percent of listeriosis illnesses associated with deli meat in the United States are associated with deli meat sliced and packaged at retail. FSIS and FDA recently completed a risk assessment evaluating retail practices and conditions that contribute to the risk of listeriosis from deli meats, cheeses, and salads prepared in retail delis. This interagency risk assessment identified slicers as a major source of Lm cross-contamination of deli meats prepared at retail.
Environmental samples collected from slicers at retail during foodborne illness investigations often indicate improper cleaning and sanitization of surfaces. This is due to the fact that most seams between the connected parts of a typical deli slicer are sealed with gaskets and sealants. Over time, these seams become worn and degraded as a result of the heavy use and cleaning processes that deli slicers undergo.
As these gaskets and seals degrade, tiny spaces can form, which are difficult to clean and sanitize. Consequently, these spaces can trap food particles and moisture, creating environments where microorganisms and biofilms (bacterial film that is attached to a surface and protects the organism) form and grow.
Regular physical inspection and monitoring the condition of your slicers (and taking appropriate action when necessary) can reduce the likelihood that the bacterium can establish itself within your establishment. Slicer components identified by the FDA as “problem areas” for cracks and broken, missing, or unattached parts include:
- The ring guard mount, which may accumulate food debris;
- The blade guard, which may accumulate food particles on the inside at the white plastic piece; and
- The slicer handle, which can trap debris under the handle itself.
You should be sure to:
- Thoroughly clean and sanitize deli slicers in accordance with the manufacturer’s instructions at least once every 4 hours.
- Routinely examine the condition of seams, seals, and gaskets to ensure their integrity while the slicer is assembled and before breaking down for cleaning and sanitizing.
- Look in hard-to-reach areas for food and liquid debris.
- If a seal or gasket is broken, missing, unattached, defective, or otherwise not performing its function, remove the slicer from service immediately and contact the slicer manufacturer for repair or replacement.
- Ensure all repairs are performed by the manufacturer’s authorized service representative or made using repair kits available from, or provided by, the original manufacturer.
- Have the slicer professionally serviced according to the manufacturer’s recommended schedule. Ensure that the servicing includes examination of all seams and the routine replacement of seals and gaskets (this may require that components be removed and reattached with sealants or gaskets).
Ultimately, it’s up to you to ensure that your slicers and facility equipment remain free of Lm. And, by properly cleaning, sanitizing, and inspecting your instructions at least once every 4 hours, you can go a long way toward maintaining an Lm-free establishment.
For more information or to obtain food safety resources on Lm, contact the Small Plant Help Desk at (877) 374-7435, or complete the FSIS food safety resources order form on our Web site at: www.fsis.usda.gov/wps/portal/fsis/topics/regulatory-compliance/haccp/resources-and-information/food-safety-resources-svsp-outreach/svsp-brochure.
In addition, the September 2012 version of the “FSIS Compliance Guideline: Controlling Lm in Post-lethality Exposed Ready-to-Eat Meat and Poultry Products” may be accessed from FSIS’ Web site at www.fsis.usda.gov/wps/wcm/connect/d3373299-50e6-47d6-a577-e74a1e549fde/Controlling_LM_RTE_guideline_0912.pdf?MOD=AJPERES. The guideline will be updated and made available in late 2013.
For more information on how to clean and sanitize deli slicers properly, visit the FDA’s Web site at: http://www.fda.gov/food/guidanceregulation/retailfoodprotection/industryandregulatoryassistanceandtrainingresources/ucm240672.htm.
Commonly Asked Questions & Answers
Q. If an establishment elects to write Hazard Analysis and Critical Control Point (HACCP) monitoring results on a piece of paper or notepad and then later transcribe the information onto the HACCP record, should the piece of paper or notepad be maintained as part of the HACCP records?
A. Yes. An establishment needs to maintain either a copy of or the actual piece of paper or notepad and have it available to FSIS for review. In addition, the HACCP plan should provide for this recordkeeping system being used for monitoring (9 CFR 417.2(c)(6)). The HACCP record would need to be a transcription of the information on the paper or notepad by the same or different person, which includes the time, date, and initials or name of the person that recorded the original data onto the piece of paper or notepad.
Small Plant News
Editor in Chief: Daniel P. Puzo
Editor: Keith Payne
Managing Editor: Jane Johnson, DVM
Manager: Sally Fernandez
Layout/Design: Gordon E. Wilson, Duane Robinson
Contributing Writer: Jeff Tarrant, Commander, U.S. Public Health Service
Office of Outreach, Employee Education and Training: Michael G. Watts, Assistant Administrator
Small Plant News, USDA/FSIS, Patriots Plaza III, Rm. 9-267A, Mailstop 3778,
1400 Independence Ave., SW, Washington, DC 20250. (800) 336-3747; E-mail: SmallPlantNews@fsis.usda.gov
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