Risk Mapping and Listeria monocytogenes Transfer in Retail Delis Karin Hoelzer, PhD FDA / Cornell University Interagency Risk Assessment - L. monocytogenes in Retail Delicatessens Public Meeting Washington, DC - May 22 nd, 2013

Goal: Leverage knowledge to prevent cross - contamination Today’s presentation addresses 4 questions: 1.Which environmental sites are the biggest concern? 2.Likelihood of transfer to food (direct / indirect)? 3.Proportion of bacteria transferred? 4.Efficacy of cleaning / sanitization in removing contamination? Objective: prevent / minimize environmental cross-contamination 2 / 25 May 22 nd, 2013 Interagency Risk Assessment--Listeria monocytogenes in Retail Delicatessens Public Meeting

Outline: Risk mapping & L. monocytogenes transfers 1.Introduction 2.Establishing a risk map of L. monocytogenes in retail delis: 1.Selection of environmental sites & contamination events 2.Expert elicitation of L. monocytogenes transfer dynamics 3.Creating a risk map of L. monocytogenes in retail delis 3.Estimating L. monocytogenes transfer coefficients 4.Estimating the efficacy of cleaning & sanitization 5.Summary & conclusions 3 / 25 May 22 nd, 2013 Interagency Risk Assessment--Listeria monocytogenes in Retail Delicatessens Public Meeting

Introduction: Listeriosis is a very serious clinical disease The clinical symptoms: - Gastroenteritis - Septicemia - Meningitis / encephalitis - Stillbirth / fetal loss - Other (e.g., joints, skin) (source: Hoelzer et al., Vet. Res. 43:18) 4 / 25 May 22 nd, 2013 Interagency Risk Assessment--Listeria monocytogenes in Retail Delicatessens Public Meeting

Introduction: Cross-contamination at retail is a concern FSIS risk assessment of L. monocytogenes in deli meats: Highest risk for retail-sliced deli meats: -Much greater risk than if pre-packaged -Growth at retail contributes to risk -Retail – sliced deli meats account for ~ 70 % of deli-meat associated deaths (source: Endrikat et al., JFP 73 (4): ) 5 / 25

Introduction: Listeria is common in the retail environment (source: Hoelzer et al., JFP 74 (7): ) Cross-sectional survey of L. monocytogenes in NY retail delis L. monocytogenes contamination: -Extremely common -Highly variable across establishments -Most common in non-food contact sites -Variable across food-contact sites -Store characteristics some impact 6 / 25 May 22 nd, 2013 Interagency Risk Assessment--Listeria monocytogenes in Retail Delicatessens Public Meeting

Introduction: Risk maps analyze risks & can guide actions Likelihood of occurrence Expected impact High risk Immediate action Medium risk Detect & monitor Medium/low risk Monitor Low risk Low control Risk = Likelihood of occurrence * expected impact 7 / 25 May 22 nd, 2013 Interagency Risk Assessment--Listeria monocytogenes in Retail Delicatessens Public Meeting

Introduction: A risk map is useful to focus interventions Prevalence of contamination Probability of transfer to food High risk Immediate action Medium risk Detect & monitor Medium/low risk Monitor Low risk Low control 8 / 25 May 22 nd, 2013 Interagency Risk Assessment--Listeria monocytogenes in Retail Delicatessens Public Meeting

Outline: Risk mapping & L. monocytogenes transfers 1.Introduction 2.Establishing a risk map of L. monocytogenes in retail delis: 1.Selection of environmental sites & contamination events 2.Expert elicitation of L. monocytogenes transfer dynamics 3.Creating a risk map of L. monocytogenes in retail delis 3.Estimating L. monocytogenes transfer coefficients 4.Estimating the efficacy of cleaning & sanitization 5.Summary & conclusions 9 / 25 May 22 nd, 2013 Interagency Risk Assessment--Listeria monocytogenes in Retail Delicatessens Public Meeting

Risk mapping: Site selection requires stakeholder input Source: Hoelzer et al. 2012; Risk Analysis 32 (7): Sites & transfer events included in risk map: Selection based on: Literature review Industry experts Academic experts Regulatory experts (federal, states) Events: transfer to food / hands / food contact surface Sites: 31 environmental sites, hands & product 10 / 25 May 22 nd, 2013 Interagency Risk Assessment--Listeria monocytogenes in Retail Delicatessens Public Meeting

Expert elicitation: Responses differed, but not by employer Source: Hoelzer et al. 2012; Risk Analysis 32 (7): Study design: ‘Delphi’ method 45 experts enrolled: - 20 from retail industry - 25 from the states 2 questionnaires telephone conference 11 / 25

Expert elicitation: Hands as cross-contamination vehicles Source: Hoelzer et al. 2012; Risk Analysis 32 (7): / 25 May 22 nd, 2013 Interagency Risk Assessment--Listeria monocytogenes in Retail Delicatessens Public Meeting

Expert elicitation: Transfer from FCS to product most likely Source: Hoelzer et al. 2012; Risk Analysis 32 (7): / 25 May 22 nd, 2013 Interagency Risk Assessment--Listeria monocytogenes in Retail Delicatessens Public Meeting

Expert elicitation: Transfer from hand-touch surfaces likely Source: Hoelzer et al. 2012; Risk Analysis 32 (7): / 25 May 22 nd, 2013 Interagency Risk Assessment--Listeria monocytogenes in Retail Delicatessens Public Meeting

Risk mapping: Risk maps analyze risks & can guide actions Likelihood of occurrence Expected impact High risk Immediate action Medium risk Detect & monitor Medium/low risk Monitor Low risk Low control Risk = Likelihood of occurrence * expected impact 15 / 25 May 22 nd, 2013 Interagency Risk Assessment--Listeria monocytogenes in Retail Delicatessens Public Meeting

Risk mapping: FCS’s are the sites of greatest concern Milk crates Floor / floor drain Walk-in cooler Sink Produce prep. area Cart wheels Product Deli case Utensils Slicer (1 st slice) Slicer (10 th slice) Analyzing the retail deli risk map: Based on 2 factors: - Pathogen prevalence - Transfer probability Considers evidence: - Amount of data (i.e. bubble size) - Consent among experts (i.e., legend font size) 16 / 25 May 22 nd, 2013 Interagency Risk Assessment--Listeria monocytogenes in Retail Delicatessens Public Meeting

Outline: Risk mapping & L. monocytogenes transfers 1.Introduction 2.Establishing a risk map of L. monocytogenes in retail delis: 1.Selection of environmental sites & contamination events 2.Expert elicitation of L. monocytogenes transfer dynamics 3.Creating a risk map of L. monocytogenes in retail delis 3.Estimating L. monocytogenes transfer coefficients 4.Estimating the efficacy of cleaning & sanitization 5.Summary & conclusions 17 / 25 May 22 nd, 2013 Interagency Risk Assessment--Listeria monocytogenes in Retail Delicatessens Public Meeting

Transfer coefficients: Transfer efficacy is highly variable Source: Hoelzer et al. 2012; IJFM 157: Transfer coefficient findings: Some transfers highly efficient Some transfers very inefficient Transfer efficacy varies by: - source / recipient sites - materials - experimental conditions - transfer characteristics - individual replicates Widespread contamination with low levels possible Need to consider variability 18 / 25 May 22 nd, 2013 Interagency Risk Assessment--Listeria monocytogenes in Retail Delicatessens Public Meeting

Transfers during slicing: Contamination can be widespread Source: Hoelzer et al. 2012; IJFM 157: / 25

Outline: Risk mapping & L. monocytogenes transfers 1.Introduction 2.Establishing a risk map of L. monocytogenes in retail delis: 1.Selection of environmental sites & contamination events 2.Expert elicitation of L. monocytogenes transfer dynamics 3.Creating a risk map of L. monocytogenes in retail delis 3.Estimating L. monocytogenes transfer coefficients 4.Estimating the efficacy of cleaning & sanitization 5.Summary & conclusions 20 / 25 May 22 nd, 2013 Interagency Risk Assessment--Listeria monocytogenes in Retail Delicatessens Public Meeting

Cleaning & sanitization: Soiled surfaces are a problem Modified from: Hoelzer et al. 2012; IJFM 157: Cleaning and sanitization: Sanitizers differ in efficacy Ineffective on soiled surfaces Efficacy impacted by: - exposure time - sanitizer concentration - inoculum concentration - individual study Efficient removal possible Rel. low efficiency possible Need to consider variability 21 / 25 May 22 nd, 2013 Interagency Risk Assessment--Listeria monocytogenes in Retail Delicatessens Public Meeting

Outline: Risk mapping & L. monocytogenes transfers 1.Introduction 2.Establishing a risk map of L. monocytogenes in retail delis: 1.Selection of environmental sites & contamination events 2.Expert elicitation of L. monocytogenes transfer dynamics 3.Creating a risk map of L. monocytogenes in retail delis 3.Estimating L. monocytogenes transfer coefficients 4.Estimating the efficacy of cleaning & sanitization 5.Summary & conclusions 22 / 25

Conclusions: Listeria transfers in retail deli environments Transfers from environmental sites to food: Food contact surfaces greatest concern: - high probability of transfer if contaminated - contamination rel. unlikely but possible - variable amounts of bacteria transferred - contamination can become widespread - occasionally high – efficiency transfers Non-food contact surfaces some concern: - contamination is very common - transfer to food rel. unlikely but possible - transfer to hands / FCS’s major concern Efficacy of cleaning / sanitization: Effective on clean surfaces, but: - sanitizer efficacy differs - external condition important - lower efficacy possible Ineffective on soiled surfaces: - impact differs by sanitizer - cleaning (& drying) important - potential residual bacteria Net efficacy of sanitizers: - difficult to evaluate - levels of Listeria unclear 23 / 25 May 22 nd, 2013 Interagency Risk Assessment--Listeria monocytogenes in Retail Delicatessens Public Meeting

Acknowledgements: Too many contributors to name -Everyone at FDA CFSAN, in particular: Sherri Dennis Régis Pouillot Retail Food & Cooperative Program Staff -Cornell University, in particular: Martin Wiedmann Haley Oliver (now at Perdue University) Martin Wells Yrjo Grohn Food Safety Laboratory -USDA FSIS & FSIS contractors, in particular: Janell Kause Meryl Silverman Dan Gallagher (FSIS Contractor/VA Tech) -Everyone else who contributed to the research, including: Food Marketing Institute - in particular Jill Hollingsworth & Larry Kohl for their support of the expert elicitation study Everyone at the enrolled ‘state’ departments that contributed to the expert elicitation study New York State Department of Agriculture & Markets – in particular Stephen Stich and Daniel Rice, for their support of the cross-sectional study of L. monocytogenes in NY retail establishments Everyone else who contributed! This work was supported by the USDA Food Safety and Inspection Service (contact no. AG-3A94-C ). K. Hoelzer was supported by Morris Animal Foundation Fellowship Training Grant Do8FE-403 for part of this work. This work was supported, in part, by appointments to the Research Participation Program at the Center for Food Safety and Applied Nutrition administered by the Oak Ridge Institute for Science and Education through an interagency agreement between the US Department of Energy and the US Food and Drug Administration. 24 / 25

QUESTIONS? NOTE: All literature citations available from presenter on request. 25 / 25 May 22 nd, 2013 Interagency Risk Assessment--Listeria monocytogenes in Retail Delicatessens Public Meeting