Current FDA Activities Related to the Listeria monocytogenes Action Plan

Objective 1: Develop and revise guidance for processors that manufacture or prepare ready-to-eat foods and develop or revise guidance for retail and food service and institutional establishments.

• On February 6, 2008, FDA announced that was issuing for public comment a draft "Guidance for Industry: Control of Listeria monocytogenes in Refrigerated or Frozen Ready-To-Eat Foods".
• On March 12, 2007, FDA issued draft final guidance for enhancing the safety of the production of fresh-cut produce, "Guide to Minimize Microbial Safety Hazards of Fresh Fruits and Vegetables."
• FDA, in cooperation with Michigan State University, will continue to examine the levels of Listeria monocytogenes (Lm) transferred in retail food establishments. Specifically, the project is to study transfer rates between foods contaminated with Lm and food contact surfaces (i.e., slicing machines, knives, spoons, etc.). This was a grant awarded through the Center for Food Safety and Applied Nutrition's (CFSAN) Office of Science collaborative grant process in 2002. The researchers are writing a paper for peer review. These results should be considered as we move forward and discuss appropriate intervention strategies at retail.
• FDA reviewed the Model Food Code to determine if provisions that address preventive controls, such as approved source, date marking, and cold-holding times and temperatures, warrant revision.
  • The 2005 Food Code was modified in Section 3-501.17 to amend the date marking provisions to include exemptions from date marking of foods prepared and packaged by a food processing plant inspected by a regulatory authority. The food products exempted included certain classes of cheeses and deli salads and other exemptions based on the Lm Risk Assessment (Conference for Food Protection numbered CFP 2004-III-006; 2004-III-14; 2004-III-017).
  • In the Supplement to the 2005 Food Code, released October 5, 2007, an allowance was removed that had permitted the cold holding of potentially hazardous foods at temperatures up to 7°C (45°F) (rather than the prevailing maximum of 5°C (41°F)) in existing refrigeration equipment under certain conditions.
  • The Conference for Food Protection developed a guidance document detailing the use of targeted sanitation procedures to assist in the control of Lm entitled "Voluntary Guidelines of Sanitation Practices Standard Operating Procedures and Good Retail Practices To Minimize Contamination and Growth of Listeria monocytogenes Within Food Establishments".
• At their 2004 meeting, the Conference for Food Protection (CFP) accepted two HACCP Manuals developed by FDA and reviewed by the CFP HACCP Committee. FDA issued these manuals in April 2006 to the retail and food service industry and state and local regulatory professionals on the use of HACCP principles to identify and control risk factors contributing to foodborne illness. These manuals outline the identification and control of risk factors by industry operators and the use of risk-based inspections by regulators. Further, many of the intervention strategies outlined in the Manuals pertain to the control of Lm and other pathogens. The manuals have been widely disseminated to state and local regulatory officials and industry. The two Manuals are:
  • Managing Food Safety: A Manual for the Voluntary Use of HACCP Principles for Operators of Food Service and Retail Establishments.
  • Managing Food Safety: A Regulator's Manual For Applying HACCP Principles to Risk-based Retail and Food Service Inspections and Evaluating Voluntary Food Safety Management Systems.
• FDA will promote the inclusion of Lm control strategies in future guidance documents that address food processing at retail operations (e.g., smoked seafood, specialty meats).
  • FDA representatives worked with the Association of Food and Drug Officials (AFDO), the University of Florida, and Florida A&M University to develop guidance for food processing at retail. These guidance documents have been finalized and released. The draft guidance documents were specifically reviewed to assess the risk of Lm and the organism was identified as a hazard in a number of these guidance documents (e.g., Smoked Seafood, Cured and Hot Smoked Sausage).

Objective 2: Develop and deliver training and technical assistance for industry and food safety regulatory employees.

• The 2006 Conference for Food Protection hosted a 1-day workshop on "Interventions for Listeria monocytogenes in Retail Food Establishments". The workshop topics included:
  • The introduction of new and emerging science related to Listeria monocytogenes
  • Factors that affect growth, survival, and control of Listeria monocytogenes
  • New studies that provided information relative to the incidence of consumption of Listeria monocytogenes in retail food operations as compared to food manufacturing establishments
  • The control of Listeria monocytogenes at food manufacturing and within a retail food establishment environment
  • Presentation of guidance documents for control of Listeria monocytogenes from the CFP Committee and from the Food Marketing Institute.
• Listeria monocytogenes Preventative Controls for Regulators -satellite course under development. Purpose: To review existing training for regulators and processors on preventive controls and guidance and to update and develop training for regulators to reduce Lm related illnesses. Mode: Satellite/web. Satellite course (3 hours in length) Web course (1 hour in length) Primary Audience: FDA and state/local regulators of retail food, milk and manufactured food (includes seafood, except shellfish) operations. Secondary audience: industry.

Objective 3: Enhance consumer and health care provider information and education efforts.

• Educational programs about the risks of listeriosis have taken place through the media, health professional organizations, contacts with authors of books on pregnancy, and educational programs for special at-risk groups including seniors and pregnant women. During 2003-2005, CFSAN participated in a program of health fairs utilizing Hispanic radio and television. Health messages on the risk of listeriosis are delivered over the Spanish language radio and television programs and information is distributed at health fairs in Hispanic areas. A further specialized campaign targeted to the Latino community on the concerns of queso fresco cheese was launched in the spring of 2005. The program utilizes the Hispanic media and community outreach workers (promotoras) to get the message out. A public health educational campaign by the public-private Partnership for Food Safety Education is underway to advise consumers to keep their refrigerators at 40 degrees Fahrenheit to prevent foodborne illness, including listeriosis. Information has been released through the media and is also being disseminated through grocery stores where refrigerator thermometers are promoted.

Objective 4: Review, redirect, and revise enforcement and regulatory strategies including microbial product sampling and analytical methods.

• On February 6, 2008, FDA announced that it was issuing for public comment a draft Compliance Policy Guide (CPG) that, when finalized, would set two risk-based limits for L. monocytogenes in Ready-To-Eat (RTE) foods. FDA's enforcement policy for RTE foods that support the growth of L. monocytogenes would remain unchanged. FDA would continue to consider legal action, on a case-by-case basis, if L. monocytogenes is detected in a RTE food that supports growth based on FDA's analytical method, which can detect 1 cell per 25 grams (g) of food (equivalent to 0.04 cells/g). However, in light of the Risk Assessment, FDA would now consider legal action, on a case by case basis, if L. monocytogenes is present in a RTE food that does not support its growth at or above 100 cells/g. This guidance would further protect the public health by more sharply focusing FDA's resources on areas of greatest risk.
• FDA has announced a public meeting, to be held March 28, 2008 in College Park, MD, to discuss the draft CPG to set two risk-based limits for L. monocytogenes in RTE food.
• The National Advisory Committee on Microbiological Criteria for Foods (NACMCF) adopted these two documents on August 27, 2004 - 1) Requisite Scientific Parameters for Establishing the Equivalence of Alternative Methods of Pasteurization and 2) Considerations for Establishing Safety-Based Consume-By Date Labels for Refrigerated Ready-to-Eat Foods.
• FDA's Bacteriological Analytical Manual (BAM) which presents the agency's preferred laboratory procedures for microbiological analyses of foods and cosmetics is updating manual to include quantitative method for Lm.
• On December 24, 2003, Hogan & Hartson, L.L.P filed a Citizens' Petition on behalf of a coalition of fifteen leading trade associations pursuant to sections 402(a)(1) and 701(a) of the Federal Food, Drug, and Cosmetic Act (FFDCA) and 21 C.F.R. § 109.4. The Petition requested that FDA amend 21 C.F.R. Part 109 to establish a regulatory limit for Listeria monocytogenes of 100 colony forming units per gram (CFU/g) in foods that do not support growth of the microorganism. On May 24, 2004, FDA published a notice the Federal Register announcing the availability of the Petition and requested comments until August 9, 2004. The Agency is in the process of responding to the Citizens' Petition.

Objective 5: Enhance Disease Surveillance and Outbreak Response

• FDA participates in PulseNet, a national molecular subtyping network for foodborne disease surveillance, which was established by the Centers for Disease Control and Prevention (CDC) in 1996. Food and environmental bacterial pathogens, including Lm, are subtyped and characterized using pulsed-field gel electrophoresis (PFGE) by FDA Office of Regulatory Affairs (ORA) laboratories and the molecular patterns are submitted by FDA CFSAN to PulseNet. These patterns are routinely compared to the PulseNet database that primarily consists of patterns from clinical isolates. Patterns from the food and clinical isolates that "match" suggest a potential link and are further investigated to determine if there is an epidemiological association in a foodborne outbreak. FDA CFSAN routinely monitors the PulseNet listserv as a possible early alert to a foodborne outbreak.
• FDA CFSAN and FDA's ORA are more actively conducting follow-up investigations when there is a match between a food and clinical PFGE pattern involving single cases of listeriosis to determine if there is an epidemiological link with an FDA regulated product.
• FDA CFSAN has a staff person located at CDC's Food Safety office in Atlanta, Georgia. This on-site relationship facilitates communication and provides early alerts to foodborne outbreaks involving FDA regulated products.
• FoodNet completed a manuscript based on a 3 year case/control study for risk factors associated with Lm infection. On multivariate analysis in the manuscript, melons eaten outside the home and hummus eaten outside the home were risk factors. The manuscript was published in January, 2007 issue of Clinical Infectious Diseases.
• The original Healthy People (HP) 2010 baseline line (1997) for Lm was an incidence of 0.5 cases per 100,000, and the 10 year target was a 50% reduction to 0.25 cases per 100,000. The National Food Safety Strategic Plan baseline (1997) for Lm was an incidence of 0.5 cases per 100,000 and the 5 year goal was a 50% reduction to 0.25 cases per 100,000. - After re-analysis of the FoodNet data, the baselines and targets for HP2010 for Lm have been revised: The revised HP2010 baseline line (1997) for Lm is an incidence of 0.47 cases per 100,000, and the 10 year target is a 50% reduction to 0.24 cases per 100,000.
• Year followed by the incidence (per 100,000) of Listeria monocytogenes infections identified in FoodNet:
  • Baseline 1997 (0.47)
  • 1998 (0.55)
  • 1999 (0.46)
  • 2000 (0.34)
  • 2001( 0.27),
  • 2002 (0.26)
  • 2003 (0.33)
  • 2004 (0.27)
  • 2005 (0.30)
  • 2006 (0.31)
  • 2010 objective (0.24)
• Incidence in 2002 was close to the 2010 objective and then increased slightly to a plateau that exceeds the objective by approximately 0.05 cases/100,000/year. Efforts are necessary to clarify the most important factors for the remaining unacceptable risk so additional focused interventions can be instituted.
• FoodNet has tested and implemented a new Lm surveillance form which is applied to each case of Lm occurring in FoodNet sites. Information on the form obtained in prospective interviews includes food consumption histories. This information is used to help rapidly identify food vehicles in Lm outbreaks detected through PulseNet. Many states other than FoodNet sites are also using this new surveillance form. In 2004-2006, the new case report forms were completed for 82% of listeriosis cases reported to FoodNet. Of these cases, 40% consumed hot dogs in the month before onset of illness, 38% consumed turkey deli meat, and 10% consumed Mexican-style soft cheese.

Objective 6: Coordinate research activities to refine the Risk Assessment, enhance preventative controls, and support regulatory, enforcement, and educational activities.

• Use the Lm risk assessment to focus Lm coverage in field programs namely to focus on high risk products as determined by the risk assessment.
• Of the 57 Mexican personal cheese importations tested from September 2 to October 2, 2003 during an FDA blitz at the Mexican border; 39(68%) of the 57 were determined to be made from raw milk, 32(56%) of the 57 were positive for generic Escherichia coli, 32(56%) of the 57 were positive for Staphylococcus aureus, 7(12%) of the 57 were positive for Salmonella spp., and 5(8%) of the 57 were positive for Lm. All isolations were confirmed by FDA laboratory analysis.
• Docket No. 2005N-0065. Published 3-4-05. Notice for request for comments and for scientific data and information concerning foodborne Listeria monocytogenes in smoked finfish, and evaluation of Food Code provisions that address preventive controls for Lm in retail and foodservice establishments. Submitted comments are in review at FDA/CFSAN.
• Two research projects are being completed at CFSAN. The first examines the competition between Lm and spoilage microorganisms in both pure cultures in broth and in foods. This will help explain the behavioral interactivity between spoilage flora and Lm.  The second modeled the lag phase of Lm cells that are in different physiological states (i.e., exponential growth, stationary, desiccated, frozen) when placed in broth under differing headspace carbon dioxide levels. This research will assist in the understanding of Lm as it relates to the modified atmosphere packaging area. The manuscript for the second project has been submitted to a scientific journal for publication
• Current Lm research at FDA's National Center for Food Safety and Technology (NCFST). Recovery of Listeria monocytogenes from environmental swabs (transport media). Same day identification of Lm using Pathatrix separation and concentration and real-time PCR.
• Joint Institute of Food Safety and Applied Nutrition (JIFSAN) collaborative work with University of Maryland Eastern Shore (UMES) is completed. Manuscripts were recently published (Abou-Zeid, K.A., Yoon, K.S., Oscar, T.P., Schwarz, J.G., Hashem, F.M. and Whiting, R.C. 2007. Survival and growth of Listeria monocytogenes in broth as a function of temperature, pH, and potassium lactate and sodium diacetate concentrations. J. Food Protection 70(11): 2620-2625) and submitted for publication (Abou-Zeid, K.A., Yoon, K.S., Oscar, T.P. and Whiting, R.C. Development and validation of a predictive model for Listeria monocytogenes Scott A as a function of temperature, pH and lactate and diacetate mixture. International J. Food Microbiology (submitted)).
• Supplemental quantitative risk assessment for Lm in smoked seafood to determine the steps in its production, distribution, sale, and use that contributes to the risk of listeriosis and the potential risk reduction that can be controlled by different mitigation strategies
• Docket No. 2007-0432. Published 11-28-07. Notice for request for comments and for scientific data and information concerning a risk assessment of the public health impact from foodborne Listeria Monocytogenes in soft-ripened cheese. FDA and Health Canada have agreed to develop a model for the production of soft-ripened cheese that will evaluate the public health impact of factors such as the microbiological status of milk used in cheese production, the impact of various cheese manufacturing steps, conditions during distribution and storage, and cross contamination during processing and handling. Submitted comments are in review at FDA/CFSAN.
• FDA/CFSAN is developing a risk profile for Lm in fresh-cut vegetables. The risk profile will provide a review of the available information and identification of major knowledge gaps for the purpose of research planning and priority setting. This information will provide background knowledge needed by Agency risk managers to identify new approaches to controlling this pathogenic foodborne bacterium, and to develop effective food safety guidance for the industry and consumers.
• FDA/CFSAN is in the process of developing a risk profile for pathogens in cheeses to determine potential strategies for risk reduction with these products.

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Quantitative Assessment of Relative Risk to Public Health from Foodborne Listeria monocytogenes Among Selected Categories of Ready-to-Eat Foods

FDA Food Code

Draft Guidance for Industry: Control of Listeria monocytogenes in Refrigerated or Frozen Ready-To-Eat Foods February 7, 2008

Draft Compliance Policy Guide Sec. 555.320 Listeria monocytogenes; Notice of Public Meeting Federal Register Notice, February 7, 2008

Draft Compliance Policy Guide Sec. 555.320 Listeria monocytogenes; Availability Federal Register Notice, February 7, 2008