GUIDELINES FOR FOODBORNE DISEASE OUTBREAK RESPONSE
THIRD EDITION Table of Contents
FOREWARD ...... 5
ACKNOWLEDGMENTS ...... 6
CHAPTER 1 | The Evolving Challenge of Foodborne Outbreak Response . . 15 1.0 Introduction ...... 16 1.1 The Burden of Foodborne Illness in the United States . . 16 1.2 Growing Complexity of the Food Supply ...... 18 1.3 Enhanced U.S. Foodborne Illness Surveillance Systems . .21 1.4 Foodborne Outbreak Response and Systems Change . . .24
CHAPTER 2 | Legal Preparedness for the Surveillance and Control of Foodborne Illness Outbreaks ...... 27 2.0 Introduction ...... 28 2.1 Public Health Legal Preparedness ...... 28 2.2 Legal Framework for Surveillance and Disease Reporting .31 2.3 Protection of Confidentiality and Authority to Access Records ...... 34 2.4 Legal Framework to Prevent or Mitigate Foodborne Illness Outbreaks ...... 36 2.5 Evolving Legal Issues ...... 40 2.6 Public Health Investigations as the Basis for Further Action .41 2.7 CIFOR Legal Preparedness Resources ...... 42 2 Council to Improve Foodborne Outbreak Response
Table of Contents
CHAPTER 3 | Planning and Preparation: Building Teams ...... 47 3.0 Introduction ...... 48 3.1 Roles ...... 48 3.2 Outbreak Investigation and Control Team ...... 56 3.3 Planning to Rapidly Expand and Contract Investigation and Control Team Structure ...... 58 3.4 Response Resources ...... 59 3.5 Communication Plans ...... 61 3.6 Planning for Recovery and Follow-Up ...... 63
CHAPTER 4 | Foodborne Illness Surveillance and Outbreak Detection . . . 67 4.0 Introduction ...... 68 4.1 Pathogen-Specific Surveillance ...... 70 4.2 Complaint Systems ...... 77 4.3 Syndromic Surveillance ...... 84
CHAPTER 5 | Cluster and Outbreak Investigation ...... 87 5.0 Introduction ...... 88 5.1 Outbreak Investigation Initiation ...... 96 5.2 Define and Find Cases ...... 98 5.3 Generate Hypotheses about Likely Sources ...... 100 5.4 Test Hypotheses ...... 103 5.5 Evaluate Evidence to Solve Point of Contamination and Source of the Food ...... 111 5.6 Implement Control Measures, Investigation Close-Out, and Reporting ...... 113 2020 | Guidelines for Foodborne Disease Outbreak Response 3
Table of Contents
CHAPTER 6 | Control Measures and Prevention ...... 115 6.0 Introduction ...... 116 6.1 Information-Based Decision Making ...... 116 6.2 Communications With the Public ...... 118 6.3 Communications With Response Partners and Stakeholders ...... 120 6.4 Control Measures ...... 121 6.5 Outbreaks Involving Commercially Distributed Foods . .126 6.6 Outbreak Wrap-up Activities ...... 130
CHAPTER 7 | Special Considerations for Multijurisdictional Outbreaks . . . 137 7.0 Introduction ...... 138 7.1 Categories and Frequency of Multijurisdictional Outbreaks ...... 138 7.2 Multijurisdictional Outbreak Detection ...... 140 7.3 Identifying and Investigating Sub-Clusters ...... 142 7.4 Coordination of Multijurisdictional Investigations . . . 143 7.5 Multijurisdictional Outbreak Investigation After-Action Reports and Reporting to NORS ...... 146
CHAPTER 8 | Performance Metrics for Foodborne Illness Programs . . . . 147 8.0 Introduction ...... 148 8.1 Purpose and Intended Use ...... 148 8.2 Performance Metrics ...... 150
Foreword
Foodborne diseases and outbreaks remain a substantial cause of preventable morbidity and mortality in the United States and worldwide. It is estimated that over 9 million cases of foodborne illness occur in the United States each year. Of these, only a small fraction are associated with recognized outbreaks. It is widely believed, however, that outbreaks are substantially under-recognized and under-reported, and as our ability to detect and investigate clusters of illness improves, the proportion that are due to outbreaks or an identified source will inevitably increase. This is of great importance, as outbreaks provide an opportunity to identify food safety practices, environmental and other contributing factors, clarify attribution of illness to specific commodities, and improve mitigation and prevention of future events.
The Council to Improve Foodborne Outbreak Investigations (CIFOR) is a multidisciplinary collaboration of national associations and federal agencies working together since 2006 to improve methods to detect, investigate, control and prevent foodborne disease outbreaks. Council members represent large agencies and groups with substantial expertise in epidemiology, environmental health, public health laboratory activities and food regulation at the local, state and federal levels. While a variety of discipline-specific materials are available, these Guidelines are intended to be a unique resource combining the perspectives of multiple disciplines and jurisdictional levels, emphasizing the importance of teamwork, coordination, and communication that are critical for rapid, efficient and successful outbreak response.
This 3rd Edition of these Guidelines provides important updates and a more streamlined format compared to earlier versions. It also addresses rapid and continuing changes in many aspects of food safety, including laboratory technology, data sharing, improved disease detection methods, increasing centralization of food production, and changing eating habits.
Previous editions of these Guidelines (along with a Toolkit and numerous other materials available from CIFOR at http://www.cifor.us/ ) have been widely used, and have provided a base for numerous training sessions of local and state agencies, and a model for development of jurisdiction-specific guidelines. They have also been used internationally (including a Chinese translation), and we hope that this edition is even more widely utilized.
Tim Jones, MD Chief Medical Officer Tennessee Department of Health Nashville, TN Acknowledgements
PARTICIPANTS IN DEVELOPMENT OF THE THIRD EDITION OF THE CIFOR GUIDELINES
• Association of Food and Drug Officials (AFDO)
• Association of Public Health Laboratories (APHL)
• Association of State and Territorial Health Officials (ASTHO)
• Centers for Disease Control and Prevention (CDC)
• Council of State and Territorial Epidemiologists (CSTE)
• Food and Drug Administration (FDA)
• National Association of County and City Health Officials (NACCHO)
• National Association of State Departments of Agriculture (NASDA)
• National Association of State Public Health Veterinarians (NASPHV)
• National Environmental Health Association (NEHA)
• U.S. Department of Agriculture/Food Safety and Inspection Service (USDA/FSIS)
The first edition of the Guidelines was supported by Cooperative Agreement Number 1U38HM000414-01 from CDC. The second edition was supported by Cooperative Agreement Numbers 1U38HM000414-05 and 1U38OT000143-01 from CDC. The third edition was supported by Cooperative Agreement Numbers 5U38OT000143‐05 and 1 NU38OT000297-01-00 from CDC. The findings and conclusions in this document are solely those of the authors and do not necessarily represent the official views of CDC. CIFOR MEMBERS
Co-Chair: Kirk Smith, DVM, MS, PhD; Donald Sharp, MD, DTM&H; Director, Manager, Foodborne, Waterborne, Vectorborne, Food Safety Office, DFWED and Associate and Zoonotic Diseases Section, Minnesota Director of Food Safety NCEZID, Centers for Department of Health Disease Control and Prevention
Co-Chair: Scott Holmes, MS, REHS; Ernest Julian, PhD; Chief, Office of Food Manager, Environmental Health Division, Protection, Rhode Island Department of Health Lincoln Lancaster County Health Department Gina Bare, EHS, RN, BSN; Food Safety Andre Pierce, MPA; Director, Environmental Team Lead, Boulder County Public Health Health and Safety, Wake County Environmental Health and Safety Division Ian Williams, PhD, MS; Chief, Outbreak Response and Prevention Branch, DFWED, Brandi Hopkins, MPH; Outbreak NCEZID Centers for Disease Control and and Response Coordinator, Massachusetts Prevention Department of Public Health Bureau of Environmental Health John Dunn, DVM, PhD; State Epidemiologist, Tennessee Department of Carina Blackmore, DVM, PhD, MIPL, Health ACVPM; State Epidemiologist, Florida Department of Health Karen Blickenstaff, MS; Response Staff Director, Coordinated Outbreak Response CDR Adam Kramer, ScD, MPH, RS; and Evaluation Network, Food and Drug Environmental Health, Centers for Disease Administration Control and Prevention Ki Straughn, RS; Environmental Health Christina Ferguson, MHA; Deputy Services Supervisor, Seattle-King County Director of Environmental Health, Georgia Department of Public Health Kristin Holt, DVM, MPH, USDA/ FSIS Liaison to CDC; U.S. Department of Dave Boxrud, MS; Molecular Epidemiology Agriculture Food Safety and Inspection Service Supervisor, Minnesota Department of Health 8 Council to Improve Foodborne Outbreak Response
Acknowledgements
CIFOR MEMBERS
Lisa Hainstock, RS; Food Safety Specialist, Sheryl Shaw, DVM, MPH, DACVPM; Director, Michigan Department of Agriculture and Rural Applied Epidemiology, Office of Public Health Science, Development U.S. Department of Agriculture Food Safety and Inspection Service Paul Cieslak, MD; Medical Director, Communicable Disease & Immunizations, Oregon Health Authority Susan Lance, DVM, PhD; FDA Liaison to CDC, Center for Food Safety and Applied Nutrition, Food and Robyn Atkinson-Dunn, PhD, HCLD; Director, Drug Administration Unified State Laboratories: Public Health Tim Jones, MD; Chief Medical Officer, Tennessee Roy Kroeger, REHS; Environmental Health Department of Health Supervisor, Cheyenne-Laramie County Health Department Travis Goodman, RS; RRT Program Coordinator, Office of Regulatory Affairs, Food and Drug Administration
CIFOR STAFF LEADS
Abraham Kulungara, MPH; Senior Director, Jennifer Li, MHS, Senior Environmental Health Environmental Health, Association of State and Director, National Association of County and City Territorial Health Officials Health Officials
Amy Chang, MS; Senior Program Analyst, National Kirsten Larson; Manager, Food Safety Program, Association of County and City Health Officials Association of Public Health Laboratories
Elizabeth Landeen; Associate Director, Program Sharon Shea, MHS, MT(ASCP); Director, & Partnership Development, National Environmental Food Safety Program, Association of Public Health Health Association Laboratories
India Bowman, MPH; Program Analyst, Council Thuy Kim, MPH, CFOI; Program Analyst, of State and Territorial Epidemiologists Council of State and Territorial Epidemiologists (formerly) 2020 | Guidelines for Foodborne Disease Outbreak Response 9
Acknowledgements
CIFOR GUIDELINES FOR FOODBORNE ILLNESS OUTBREAK RESPONSE, THIRD EDITION
Lead Author
Craig Hedberg, PhD; Professor, University of Minnesota
CIFOR GUIDELINES OVERVIEW
Author Donald Sharp, MD, DTM&H; Director, Food Safety Office, DFWED and Associate Director of Tim Jones, MD; Chief Medical Officer, Tennessee Food Safety NCEZID, Centers for Disease Control and Department of Health Prevention
Workgroup Members Kirsten Larson; Manager, Food Safety Program, Association of Public Health Laboratories Andre Pierce, MPA, REHS; Director, Division of Environmental Health & Safety, Wake County Michele DiMaggio, REHS; Supervising Government Environmental Health Specialist, Contra Costa County
Danny Ripley; Food and Public Facilities Protection Paul Cieslak, MD; Medical Director, Communicable Services, Metro Public Health Department Disease & Immunizations, Oregon Health Authority
CHAPTER 1 | THE EVOLVING CHALLENGE OF FOODBORNE OUTBREAK RESPONSE
Authors Paul Cieslak, MD; Medical Director, Communicable Disease & Immunizations, Oregon Health Authority Paul Cieslak, MD; Medical Director, Communicable Disease & Immunizations, Oregon Health Authority Robyn Atkinson-Dunn, PhD, HCLD; Director, Unified State Laboratories: Public Health Joseph Russell, MPH, RS; CSTE Consultant Sherri McGarry; CDC Liaison to FDA; Centers for Workgroup Members Disease Control and Prevention
Jessica Healy, PhD; Epidemiologist, Enteric Susan Lance, DVM, PhD; FDA Liaison to CDC, Diseases Epidemiology Branch, Centers for Disease Center for Food Safety and Applied Nutrition, Food and Control and Prevention Drug Administration
Kenny Yeh; Senior Advisor Science, Program Veronica Burell, REHS; Environmental Health Development, MRIGlobal Specialist II, Contra Costa County Environmental Health Kristin Holt, DVM, MPH, USDA/FSIS Liaison to CDC; U.S. Department of Agriculture Food Safety and Inspection Service 10 Council to Improve Foodborne Outbreak Response
Acknowledgements
CHAPTER 2 | LEGAL PREPAREDNESS FOR THE SURVEILLANCE, INVESTIGATION AND CONTROL OF FOODBORNE ILLNESS OUTBREAKS
Authors Lynne Madison, RS; Director, Environmental Health Division, Western Upper Peninsula Health Andy Baker-White, JD, MPH; Senior Director, Department (retired) State Health Policy, Association of State and Territorial Health Officials Robyn Atkinson-Dunn, PhD, HCLD; Director, Unified State Laboratories: Public Health Patricia Elliott, JD, MPH; President, Health | Environment Concepts Shannon O’Fallon, JD; Oregon Department of Justice Workgroup Members Sherri McGarry; CDC Liaison to FDA; Centers for Brandi Hopkins, MPH; Outbreak and Response Disease Control and Prevention Coordinator, Massachusetts Department of Public Health Bureau of Environmental Health Thuy Kim, MPH, CFOI; Program Analyst, Council of State and Territorial Epidemiologists Carlynne Cockrum, JD; U.S. Department of Agriculture Food Safety and Inspection Service
Dale Morse, MD, MS; Director, Food Safety Office, DFWED, and Associate Director for Food Safety, NCEZID, Centers for Disease Control and Prevention (retired)
CHAPTER 3 | PLANNING AND PREPARATION: BUILDING TEAMS
Authors John Tilden, DVM, MPH; CSTE Consultant
D’Ann Williams, DrPH, MS, LEHS; Chief, Kristin Holt, DVM, MPH, USDA/FSIS Liaison Center for Food Emergency Response and Defense; to CDC; U.S. Department of Agriculture Food Safety Maryland Department of Health and Inspection Service
Maha Hajmeer, PhD; Research Scientist IV, Lauren Yeung; Office of Regulatory Affairs, Food California Department of Public Health and Drug Administration
Tim Jones, MD; Chief Medical Officer, Tennessee Lisa Hainstock, RS; Food Safety Specialist, Department of Health Michigan Department of Agriculture and Rural Development Workgroup Members Maria Ishida, PhD, CPM; Director, Food Donald Sharp, MD, DTM&H; Director, Food Laboratory Division, New York State Department of Safety Office, DFWED and Associate Director of Agriculture and Markets Food Safety NCEZID, Centers for Disease Control and Prevention Michele DiMaggio, REHS; Supervising Environmental Health Specialist, Contra Costa County 2020 | Guidelines for Foodborne Disease Outbreak Response 11
Acknowledgements
CHAPTER 4 | FOODBORNE ILLNESS SURVEILLNACE AND OUTBREAK DETECTION
Authors John Besser, PhD; Deputy Chief, Enteric Diseases Laboratory Branch, Centers for Disease Control and Carlota Medus, PhD, MPH; Epidemiologist Prevention (retired) Supervisor Sr., Minnesota Department of Health Kirk Smith, DVM, MS, PhD; Manager, Dave Boxrud, MS; Molecular Epidemiology Foodborne, Waterborne, Vectorborne, and Zoonotic Supervisor, Minnesota Department of Health Diseases Section, Minnesota Department of Health
Heather Carleton, PhD, MPH; Deputy Chief, Kristal Southern, DVM, MPH, PMP; Enteric Diseases Laboratory Branch, Centers for Surveillance Epidemiologist, Office of Public Health Disease Control and Prevention Science, U.S. Department of Agriculture Food Safety and Inspection Service Workgroup Members Ryan Jepson, M(ASCP); Microbiology Supervisor, Angie Hagy, MSPH; Director of Disease Control State Hygienic Laboratory at the University of Iowa and Environmental Health, City of Milwaukee Health Department Samuel Crowe, PhD, MPH; Associate Director for Prevention (formerly National Outbreak Reporting CDR Kari Irvin, MS; CORE Deputy Director, System Team Lead), Centers for Disease Control and Food and Drug Administration Prevention David Nicholas, MPH; Chief Epidemiologist, Sheryl Shaw, DVM, MPH, Dipl ACVPM; Outbreak Investigation and Research, New York State Director, Applied Epidemiology Staff, U.S. Department Department of Health of Agriculture Food Safety and Inspection Service Jennifer Beal, MPH; Senior Epidemiologist, CORE Signals & Surveillance Team, Food and Drug Administration
Joel Sevinsky, PhD; Colorado Department of Public Health & Environment- Laboratory (Former); Principal, Theiagen Consulting, LLC 12 Council to Improve Foodborne Outbreak Response
Acknowledgements
CHAPTER 5 | CLUSTER AND OUTBREAK INVESTIGATION
Authors Hillary Booth, MPH; Foodborne Epidemiologist, Oregon Health Authority CDR Kari Irvin, MS; CORE Deputy Director, Food and Drug Administration Hugh Maguire, PhD; Program Manager, Microbiology; Colorado Department of Public Health Craig Hedberg, PhD; Professor, University of & Environment (Retired) Minnesota Ian Williams, PhD, MS; Chief, Outbreak Response Workgroup Members and Prevention Branch, DFWED, NCEZID Centers for Disease Control and Prevention Amy Woron, PhD, M(ASCP); Deputy Chief for Antimicrobial Resistance, State Laboratories Division, Kirk Smith, DVM, MS, PhD; Manager, Hawaii Department of Health Foodborne, Waterborne, Vectorborne, and Zoonotic Diseases Section, Minnesota Department of Health Carlota Medus, PhD, MPH; Epidemiologist Supervisor Sr., Minnesota Department of Health Samuel Crowe, PhD, MPH; Team Lead, National Outbreak Reporting System, Centers for Disease Control CDR Adam Kramer, ScD, MPH, RS; and Prevention Environmental Health, Centers for Disease Control and Prevention Thomas Collaro; Senior Investigator, U.S. Department of Agriculture Food Safety and David Nicholas, MPH; Chief Epidemiologist, Inspection Service Outbreak Investigation and Research, New York State Department of Health
CHAPTER 6 | CONTROL MEASURES AND PREVENTION
Authors Patty Lewandowski, MBA, MT(ASCP); Bureau Chief of Public Health Laboratories; Florida Ernest Julian, PhD; Chief, Office of Food Department of Health Protection, Rhode Island Department of Health Scott Holmes, MS, REHS; Manager, John Tilden, DVM, MPH; CSTE Consultant Environmental Health Division, Lincoln Lancaster County Health Department Joseph Russell, MPH, RS; CSTE Consultant Tracey Weeks, MS, RS; Food Protection Program Workgroup Members Coordinator, Connecticut Department of Public Health Gina Bare, RN, BSN, EHS; Food Safety Team Travis Goodman, RS; RRT Program Coordinator, Lead, Boulder County Public Health Office of Regulatory Affairs, Food and Drug Laura Whitlock, MPH; Health Communication Administration Lead, Outbreak Response and Prevention Branch, Centers for Disease Control and Prevention 2020 | Guidelines for Foodborne Disease Outbreak Response 13
Acknowledgements
CHAPTER 7 | SPECIAL CONSIDERATIONS FOR MULTIJURISDICTIONAL OUTBREAKS
Author Michele DiMaggio, REHS; Supervising Environmental Health Specialist, Contra Costa County Craig Hedberg, PhD; Professor, University of Minnesota Stephen Gladbach, Unit Chief, Microbiology Unit, Missouri State Public Health Laboratory Workgroup Members Susan Lance, DVM, PhD; FDA Liaison to CDC, Kirk Smith, DVM, MS, PhD; Manager, Center for Food Safety and Applied Nutrition, Food and Foodborne, Waterborne, Vectorborne, and Zoonotic Drug Administration Diseases Section, Minnesota Department of Health CDR William Lanier, DVM, MPH, DACVPM; Ian Williams, PhD, MS; Chief, Outbreak Response Applied Epidemiology Staff, Office of Public Health and Prevention Branch, DFWED, NCEZID Centers Science, U.S. Department of Agriculture Food Safety for Disease Control and Prevention and Inspection Service
Lisa Hainstock, RS; Food Safety Specialist, Thuy Kim, MPH, CFOI; Program Analyst, Michigan Department of Agriculture and Rural Council of State and Territorial Epidemiologists Development
CHAPTER 8 | PERFORMANCE METRICS FOR FOODBORNE ILLNESS PROGRAMS
Authors Gwen Biggerstaff, ScD, MSPH; Associate Director, Office of Support, Coordination, and Rachel Jervis, MPH; Enteric Disease Unit Implementation, Centers for Disease Control Manager, Colorado Department of Public Health and Prevention & Environment Kirk Smith, DVM, MS, PhD; Manager, Craig Hedberg, PhD; Professor, University Foodborne, Waterborne, Vectorborne, and Zoonotic of Minnesota Diseases Section, Minnesota Department of Health
Workgroup Members Scott Holmes, MS, REHS; Manager, Environmental Health Division, Lincoln Lancaster CDR Adam Kramer, ScD, MPH, RS; County Health Department Environmental Health, Centers for Disease Control and Prevention Sharon Shea, MHS, MT(ASCP); Director, Food Safety Program, Association of Public Health Diane Gubernot, DrPH, MPH; Post Response, Laboratories Coordinated Outbreak Response and Evaluation Network, Food and Drug Administration (formerly) Tim Monson, MS; Microbiologist Supervisor, Wisconsin State Laboratory of Hygiene
CHAPTER 1
The Evolving Challenge of Foodborne Illness Outbreak Response
CHAPTER SUMMARY POINTS
• Foodborne illness strikes tens of millions, hospitalizes more than 100,000, and
kills an estimated 3,000 people in the United States each year.
• The U.S. diet has changed in response to numerous factors creating new food-
safety challenges.
• Important advances in clinical laboratory techniques and public health
approaches to detect and investigate clusters of illness are being used to better
define the scope and nature of foodborne illness.
• Information systems and food-supply investigation techniques are developing
to enhance our ability to trace contaminated foods, identify and control
contamination sources, and remove contaminated food from circulation.
• Industry-driven and regulatory food-safety standards are being changed to
better address risks identified by foodborne illness outbreak investigations to
prevent similar outbreaks.
URLs in this chapter are valid as of July 11, 2019. 16 2020 | Guidelines for Foodborne Disease Outbreak Response
1 1.0 Introduction
Outbreaks of foodborne illness and their systems are developing to enhance our ability detection, investigation, and control are to trace contaminated food and eliminate it functions of several constantly changing from circulation and to glean lessons learned factors. The U.S. diet has changed in response from these investigations to prevent similar to public health recommendations; economics outbreaks. In addition, industry-driven and of food production and distribution; and the regulatory food-safety standards are being growing demands for convenience in food changed to better address risks identified by service, as well as diversity and freshness of foodborne illness outbreak investigations to foods in the marketplace. Important advances prevent similar outbreaks. have been made in clinical laboratory
ILLNESS OUTBREAK RESPONSE techniques to diagnose foodborne illnesses This chapter provides an overview of these and in public health approaches to detect and ever-changing factors. Subsequent chapters investigate clusters of illness. Information detail specific approaches used by investigators.
THE EVOLVING CHALLENGE OF FOODBORNE CHALLENGE OF FOODBORNE THE EVOLVING 1.1 The Burden of Foodborne Illness in the United States
1.1.1 In 2011, the Centers for Disease the monophasic variant of Typhimurium, Control and Prevention (CDC) estimated serotype I 4,[5],12:i:-, increased (3). that each year in the United States 47.8 million illnesses, resulting in 128,000 Because not all illnesses caused by foodborne hospitalizations and 3,000 deaths, were pathogens are individually reportable, attributable to contaminated food (1, 2). recognition of other pathogen-specific Of these illnesses, 9.4 million are caused by trends relies on surveillance of foodborne 31 known agents of foodborne illness, and illness outbreaks. CDC’s National Outbreaks the remaining 38.4 million by unspecified Reporting System (NORS) logged 20,854 agents. Tracking overall changes in the outbreaks comprising 403,110 illnesses, burden of foodborne illness from year to 16,517 hospitalizations, and 392 deaths year is not currently possible, but trends during 1998–2017 (https://wwwn.cdc.gov/ are evident in known foodborne illnesses norsdashboard/). Reporting of foodborne tracked by FoodNet (https://wwwn.cdc.gov/ illness outbreaks caused by norovirus increased foodnetfast). Most notably, the incidence of during 1998–2004, but since 2010, annual Escherichia coli O157:H7 infections dropped totals have varied little, hovering around 300 from approximately 2.5 cases per 100,000 per year. A comparison of etiologies causing population during the mid-1990s to fewer single-agent outbreaks during 2012–2017 with than 1 case per 100,000 by the mid-2000s, those during 2002–2011 showed that outbreaks accomplishing a goal of Healthy People 2010. caused by agents associated with poor food- Following early declines in the incidence of holding practices in commercial food-service Listeria and Campylobacter infections, rates establishments decreased: Bacillus cereus, down remained stable throughout the 2000s, whereas from an average of 17 outbreaks per year to the incidence of Vibrio infections increased. 10 per year; Clostridium perfringens, from 40 to Overall rates of Salmonella infections remained 32 per year; scombroid or histamine, from stable; the incidence of infection by serotypes 23 to 17 per year; and Staphylococcus aureus, Typhimurium and Heidelberg decreased; and from 27 to 12 per year. These changes most infection by serotypes Enteritidis, Javiana, and likely represent actual reductions in outbreak 2020 | Guidelines for Foodborne Disease Outbreak Response 17
1.1 The Burden of Foodborne Illness in the United States 1 ILLNESS OUTBREAK RESPONSE THE EVOLVING CHALLENGE OF FOODBORNE occurrence because the percentage of reported this burden on cost estimates of foodborne outbreaks for which no etiologic agent was illness caused by 15 major pathogens in the identified dropped from 59% in 1998 to 23% United States (Table 1.1). These 15 pathogens in 2017 (4). account for 95% of illnesses and deaths from foodborne illness acquired in the United States 1.1.2 In 2014, the U.S. Department of for which a pathogen was identified. These Agriculture’s Economic Research Service estimates include costs associated with medical (USDA–ERS) estimated the average annual treatment of acute and chronic illness, lost economic burden of foodborne illness wages of persons who recovered, and costs at $15.5 billion (5). USDA–ERS based associated with premature deaths.
Table 1.1. Estimated Annual Cost of Foodborne Illness, Estimated Total Foodborne Cases, and Average Cost per Case Identified, United States, 2013 ESTIMATED TOTAL COST PER PATHOGEN TOTAL COST FOODBORNE CASES CASE Vibrio vulnificus $319,900,000 96 $3,332,000
Listeria monocytogenes $2,834,400,000 1,591 $1,782,000
Toxoplasma gondii $3,304,000,000 86,686 $38,100
Vibrio spp. (other noncholera) $72,800,000 17,564 $8,100
Shiga toxin–producing $271,400,000 63,153 $4,300 Escherichia coli O157
Salmonella spp. (nontyphoidal) $3,666,600,000 1,027,561 $3,600
Yersinia enterocolitica $278,000,000 97,656 $2,900
Campylobacter spp. $1,928,800,000 845,024 $2,300
Vibrio parahaemolyticus $40,700,000 34,664 $1,200
Shigella (all species) $138,000,000 131,254 $1,100
Cryptosporidium parvum $51,800,000 57,616 $900
Norovirus $2,255,800,000 5,461,731 $410
Clostridium perfringens $342,700,000 965,958 $360
Non-O157 Shiga toxin–producing E. coli $27,400,000 112,752 $240
Cyclospora cayetanensis $2,300,000 11,407 $200
Source: U.S. Department of Agriculture. Cost estimates of foodborne illnesses. https://www.ers.usda.gov/ data-products/cost-estimates-of-foodborne-illnesses 18 2020 | Guidelines for Foodborne Disease Outbreak Response
1 1.1 The Burden of Foodborne Illness in the United States
1.1.3 The impact of foodborne illness on in sales of iceberg lettuce, red leaf lettuce, the food industry varies greatly, and the and endive. The impact of a second, although costs seldom are limited to one company. unrelated, outbreak of E. coli O157:H7 This impact is evident when the distribution associated with romaine lettuce in November network of the food supply is considered. The 2018 (8) was even more dramatic because impacts of recalls on the food industry are far- CDC advised consumers to avoid eating reaching, in some cases topping $10 million in romaine lettuce from any source in an effort direct costs. to remove potentially contaminated romaine from commercial distribution channels. Direct costs of recalls include notification
ILLNESS OUTBREAK RESPONSE of regulators, supply chain, and consumers; With a more comprehensive accounting product retrieval, storage, and destruction; of potential costs, researchers at the Johns unsalable product; and the additional labor Hopkins Bloomberg School of Public Health associated with these activities. These direct suggested that the cost to a restaurant for a costs do not include litigation, increased single foodborne illness outbreak can range regulatory compliance, and the impact to the from $4,000 to $2.6 million, depending on the THE EVOLVING CHALLENGE OF FOODBORNE CHALLENGE OF FOODBORNE THE EVOLVING company’s market value and brand reputation. pathogen, type of restaurant involved, and size of the outbreak. For example, a foodborne The outbreak of E. coli O157:H7 infection illness outbreak in which five people became associated with romaine lettuce grown in the sick in a fast food restaurant would result in Yuma, Arizona, growing region in April 2018 costs of approximately $4,000 if there was provides a good example of the indirect costs no loss in revenue and no lawsuits, legal fees, to the industry associated with lost sales and or fines. In contrast, a single outbreak of brand damage (6). This outbreak sickened listeriosis involving 250 persons in a fine dining 210 people in 36 states. During the week that restaurant could cost upwards of $2.6 million followed the initial news of the outbreak, sales in lost sales, lawsuits, legal fees, fines, and of romaine lettuce fell 20% (7). In addition, higher insurance premiums (9). data from Nielsen also showed marked drops
1.2 Growing Complexity of the Food Supply
U.S. food-consumption patterns change 1.2.1 A major indicator of changing diets continuously. Changes in diets and food is the consumption of fresh fruits and preferences have resulted in a greater demand vegetables. From 1996 to 2017, loss-adjusted for a broader variety of fruits, vegetables, per capita availability of fresh fruit increased and other foods. Moreover, Americans 7% from 55 to 59 pounds (10). Consumption expect to consume these foods year-round, of fresh vegetables increased only marginally driving importation from areas of the world from 68 to 70 pounds per person. During with the growing seasons necessary to meet the same time, per capita consumption of U.S. demand. Meeting global supply-chain chicken increased 30% from 40 to 52 pounds, demands also has increased the complexity whereas that of beef declined 17% from and logistics of how food is transported from 49 to 41 pounds (10). Within the arena of farm to fork. fresh produce, consumption of head lettuce declined 34% from 12 to 8 pounds per capita, whereas consumption of romaine and leaf 2020 | Guidelines for Foodborne Disease Outbreak Response 19
1.2 Growing Complexity of the Food Supply 1 ILLNESS OUTBREAK RESPONSE THE EVOLVING CHALLENGE OF FOODBORNE lettuce doubled from 3 to 6 pounds per of Shiga toxin–producing E. coli (STEC), capita, and consumption of fresh spinach Salmonella, Campylobacter, and Listeria infections nearly tripled from 0.3 to 0.9 pounds per associated with raw milk and raw milk cheeses; capita. Consumption of fresh berries also Salmonella associated with raw tuna in sushi; increased substantially. The general pattern and Campylobacter and Salmonella in minimally of these dietary changes reflects public health processed liver pates. A corresponding trend recommendations toward healthier eating (10). for raw pet foods made from meat and poultry products also has led to outbreaks among The food industry has met this demand people from handling the raw pet food, through routine importation of items once exposure to ill animals, or environmental considered out of season or exotic. According contamination in the household. to reports by USDA–ERS (11), the proportion of imported fresh fruits increased from 39% Foodborne illnesses also can be associated with in 1996 to 53% in 2016. Excluding bananas, ingestion of products not typically thought of for which there is no domestic production, as food. During 2017–2018, kratom, a tree leaf the share of imported fruits increased from with stimulant and opioid properties, caused 16% to 38%. Similarly, the percentage of illness by a variety of Salmonella serotypes. imported fresh vegetables increased from Smoking marijuana caused an outbreak of 14% to 31%. Although a high proportion salmonellosis in 1981 (12); and a cannabis- of some fresh produce items, such as mango associated toxidrome among four persons who and papaya, always have been imported, an attended the August 2014 Denver County increasingly more conventional produce items Fair was associated with consumption of are also imported. For example, the percentage chocolate bars obtained at the “LoveAll” of imported avocadoes increased from booth at the fair’s “Pot Pavilion” (13). The full approximately 14% in 1996 to 89% in 2016, legalization of cannabis products in at least and that of blueberries increased from 24% to nine other states and the District of Columbia 57% during that same period (11). since 2014 and associated sales of cannabis- infused edibles could lead to more foodborne The safety of imported food products depends illness outbreaks. However, no outbreaks from largely on the public health and food-safety cannabis products were reported to NORS systems of other countries. Recent analyses of from 2015 to 2018. foodborne illness outbreaks reported to CDC support the existence of food-safety problems 1.2.3 Changes in how food is cultivated in other countries. During 1996–2014, the or raised, processed, and distributed number of confirmed foodborne illness and where, how, and by whom food is outbreaks associated with imported foods prepared also contribute to changing increased from 3 per year to 18 per year. patterns of foodborne illness. The demand Salmonella and Cyclospora accounted for about for processed and ready-to-eat foods has led one third of the outbreaks and 75% of cases, to the industrialization of food production most due to contaminated produce from Latin with increasingly intense agricultural practices America (11). and broadening distribution of food products. Changes in agricultural, processing, or 1.2.2 Culinary preferences for undercooked packaging methods might facilitate bacterial or raw foods also contribute to more contamination or growth. Large multistate frequent infections and outbreaks caused STEC outbreaks associated with leafy green by the microorganisms associated with vegetables reflect the challenges of intensive these foods. These include classical outbreaks 20 2020 | Guidelines for Foodborne Disease Outbreak Response
1 1.2 Growing Complexity of the Food Supply
animal and fresh produce production in but the consequences of eating unsafe food a shared environment. The scale of these apply to both small and large producers. operations magnifies the impact of food- For an individual, it is equally as bad to get safety system failures, resulting in thousands STEC infection from farm-fresh strawberries of exposures and potential illnesses across harvested from a local field frequented by multiple states, and even multiple countries. wild deer as it is to get STEC infection from romaine lettuce shipped hundreds of miles Increasingly complex food-distribution systems after contamination with runoff from a cattle span the globe. Products move from farm to feed lot. Although a small producer’s limited fork through a network of farms, processors, distribution system might affect fewer people,
ILLNESS OUTBREAK RESPONSE manufacturers, packers, importers, brokers, implementing improved food-safety measures storage facilities, distribution centers, and retail might be more challenging for the small outlets. In some instances, food from a farm producer. In addition, farm direct sales (i.e., can change hands more than 10 times before farmers selling produce, eggs, and other foods it reaches a consumer. These complex supply they produced directly to retail customers, chains are maintained by a wide variety of
THE EVOLVING CHALLENGE OF FOODBORNE CHALLENGE OF FOODBORNE THE EVOLVING such as through farmers’ markets and farm record-keeping systems; outbreak investigators stands) are not included among food facilities charged with tracing foods back through the in the 2011 Food Modernization and Safety supply chain are left to decode these systems Act (FMSA) (15). In some states and local and piece together, step by step, how a food jurisdictions, these sales have been exempted reached its final destination. from food-safety regulations that pertain to other food facilities. At the same time, a counter-trend promoting local food sources and small-scale farm-to By whom and where our food is prepared also table distribution networks (sometimes termed plays a role in foodborne illness occurrence the “locavore movement” or “community- and outbreaks. Americans increasingly eat supported agriculture”) has emerged. The away from home, spending more than 50% of number of small food producers and direct- food dollars away from home, since 2010 (16). to-consumer marketing avenues (e.g., farmer’s During this period, there was considerable markets, farm stands, farm-to-school programs, growth in limited service “fast casual” and “pick-your-own” operations) also has risen. restaurants that featured more complex food According to national agriculture census data, handling than traditional fast-food restaurants. from 1997 to 2017, direct sales of agricultural The increased number of meals eaten products to the public increased by 374%, away from home most likely influenced the compared with an increase of 93% for all increase in foodborne illness. In an analysis of agricultural sales. During the same period, the foodborne illness outbreaks reported to CDC number of farms selling directly to consumers during 2009–2017, 62% were associated with increased by 18%, compared with an 8% restaurants (4, 17). In addition, studies of decrease in the total number of farms (14). sporadic and outbreak-associated foodborne In addition, most states have “cottage food” illness, including infection with STEC O157, laws, allowing small producers to cook, can, or Salmonella enterica serotypes Enteritidis and pickle outside of licensed kitchens certain foods Typhimurium, and Campylobacter jejuni suggest that are typically considered low-risk. that commercial food-service establishments, such as restaurants, play an important role in The effect of increased consumption of foodborne illness in the United States (18). locally produced foods is yet to be determined, 2020 | Guidelines for Foodborne Disease Outbreak Response 21
1.2 Growing Complexity of the Food Supply 1 ILLNESS OUTBREAK RESPONSE THE EVOLVING CHALLENGE OF FOODBORNE
Finally, the growing e-commerce in delivery verifying food purchases and dates. Whether of groceries and restaurant food directly an increased risk for illness accompanies these to consumers’ homes provides foodborne means of food distribution remains to be illness investigators with opportunities for determined.
1.3 Enhanced U.S. Foodborne Illness Surveillance Systems
A variety of surveillance systems have been to infer epidemiologic relatedness; developed to identify foodborne illness and PFGE revolutionized the detection and detect outbreaks. Some systems focus on investigation of foodborne illness outbreaks specific pathogens likely to be transmitted and led to prevention of illnesses. However, through food and have been used extensively PFGE provided limited information for decades. More recently, new surveillance about the organism itself. Rapid bacterial methods have emerged that provide data on sequencing technology and the informatics food vehicles, settings, pathogens, contributing tools needed to accommodate whole-genome factors, and environmental antecedents. sequencing (WGS) have been developed and Effective surveillance to track cases of in 2019 rapidly deployed to public health foodborne illness and outbreaks is critical to laboratories across the United States. On developing effective control strategies. July 15, 2019, WGS replaced PFGE as the primary molecular subtyping tool for 1.3.1 Changes in surveillance for human pathogen-specific surveillance. illness have affected how outbreaks are detected (Chapter 4) and investigated • Concurrent with the development of (Chapter 5). All states and territories have WGS to improve molecular subtyping, legal requirements for the reporting of certain clinical laboratories have moved away from illnesses and conditions, including illnesses traditional fecal culture in favor of culture- likely to be foodborne (e.g., salmonellosis, independent diagnostic tests (CIDTs). These campylobacteriosis, and STEC infection), by methods can rapidly identify pathogens and healthcare providers and laboratories to the expedite treatment decisions, but they do local, state, or territorial public health agency not yield the bacterial isolates required by (Chapter 2). Local and state agencies also public health officials. Many public health receive and respond to complaints of illness jurisdictions require submission of CIDT- directly from the public. The adoption of new positive specimens for subsequent culture testing methods in clinical and public health and subtyping—but this shifts the burden laboratories, as well as improved information of isolation from the clinical laboratory management systems and social media, are to the public health laboratory and delays transforming surveillance activities. cluster recognition. Conversely, CIDTs may be more sensitive and offer the prospect of • Molecular subtyping by public health detecting pathogens (e.g., enterotoxigenic laboratories has been the basis for national E. coli) that may elude detection by culture. pathogen-specific surveillance since FoodNet, the 10-site active surveillance the initiation of PulseNet in 1996. The program for infections often transmitted use of pulsed-field gel electrophoresis through foods, has increased collection of (PFGE) increased the ability to link data on use of CIDTs and on the frequency isolates from distant locations and thereby and results of reflex cultures. 22 2020 | Guidelines for Foodborne Disease Outbreak Response
1 1.3 Enhanced U.S. Foodborne Illness Surveillance Systems
• Newer technologies are likely to lead to Safety and Inspection Service (FSIS), Food recognition of more clusters and reduced and Drug Administration (FDA), and other cluster sizes than with PFGE. They also investigating agencies analyze these data to take longer, delaying cluster recognition by improve understanding of the impact of this means. foodborne illness outbreaks on human health and of the pathogens, foods, and settings • Improved epidemiologic investigation involved in these outbreaks. practices have been developed. These include the standardization of common • Specialized surveillance networks have data elements for interviewing case-patients, been developed for specific pathogens. For
ILLNESS OUTBREAK RESPONSE use of standardized hypothesis-generating example, CaliciNet is a norovirus outbreak questionnaires, increased use of consumer surveillance network of local, state, and product purchase (e.g., “shopper card”) federal public health laboratories. Network data, aggregation of case-patient exposures partners perform viral sequencing and and comparison with population reference upload sequences into CaliciNet to monitor standards, and improved subcluster circulating strains, and identify newly THE EVOLVING CHALLENGE OF FOODBORNE CHALLENGE OF FOODBORNE THE EVOLVING investigation and informational traceback emerging norovirus strains. CaliciNet methods to improve the specificity of outbreak lab data are linked to matching exposure assessments. outbreak data in NORS. CryptoNet, the first U.S. national molecular tracking system • The principles of foodborne illness complaint for a parasitic infection, was formally surveillance are being standardized (Chapter launched in 2015 to collect specimens and 4). The value of using electronic databases to characterize the molecular epidemiology to review and analyze complaints and to of infection by Cryptosporidium spp., only link complaints with pathogen-specific some of which are pathogenic for humans surveillance systems has been demonstrated. but which are typically indistinguishable Numerous social media platforms have morphologically. been evaluated to assess their potential utility to enhance conventional complaint 1.3.2 Surveillance for food-preparation surveillance. To the extent these can facilitate hazards and environmental assessments linking illnesses with exposure, rather than of outbreaks have been developed to just reinforcing the “last meal eaten” bias, identify root causes (Chapter 5) and they may warrant attention from public improve preventive controls (Chapter 6). health agencies. Routine food-safety inspections are conducted for all licensed food-service establishments by • Standards and procedures for outbreak approximately 3,000 local and 75 state and reporting have been developed for NORS. territorial agencies. Although traditionally NORS supports outbreak reporting conducted to ensure that food-service from state, local, and territorial health establishments were operating within the departments in the United States. NORS provisions of state food codes, many of which Dashboard is a public-facing, web-based are adopted from the FDA Model Food Code tool containing limited and cleaned NORS (19), inspection results are being increasingly data that can be filtered using an interactive displayed at the point of service or online interface that produces summary data, to provide information to consumers about statistics, and a variety of graphs based potential food-safety risks. A growing body of on user preferences (https://wwwn.cdc. evidence suggests that such public disclosure gov/norsdashboard). CDC, USDA’s Food of inspection results might improve restaurant 2020 | Guidelines for Foodborne Disease Outbreak Response 23
1.3 Enhanced U.S. Foodborne Illness Surveillance Systems 1 ILLNESS OUTBREAK RESPONSE THE EVOLVING CHALLENGE OF FOODBORNE inspection results and reduce the risk for illness 1.3.3 The food supply and associated transmission to patrons. environments are tested by local, state, and federal regulatory officials and the • To standardize assessment of retail food food industry. Food testing is a tool used risk factors, FDA initiated the Retail Food to assess whether an establishment’s food- Risk Factor Study to measure practices safety system is functioning adequately to and behaviors commonly identified as address hazards in food production and contributing factors in foodborne illness manufacturing and prevent foodborne outbreaks (20). Data from the initial study, illnesses. Food and environmental testing data, collected during 1998, 2003, and 2008, including molecular subtyping data, can be documented progress toward the goal of used to inform hypothesis generation during reducing contributing factors (https://www. outbreaks. Food testing data also can be used cdc.gov/nceh/ehs/nears/cf-definitions.htm) to estimate the fraction of selected foodborne at retail establishments: five of the nine illnesses caused by specific food sources, to facility types showed a statistically significant assess changes in food contamination over improvement in compliance for all 42 time, and to assess the success of regulatory contributing factors during the study period. measures. Foodborne pathogens of interest A second round of the Retail Food Study was that are isolated from food or from animal initiated in 2013 to assess food-protection or environmental sources during various manager certification and food-safety government testing programs are being management systems. One important finding characterized by WGS and the sequence data from the study was that fewer food-safety added to FDA’s GenomeTrakr BioProjects items were out of compliance in restaurants housed at NIH NCBI, where they can be having well-developed and documented compared with data from human isolates food-safety management systems (20). directly on NCBI Pathogen Browser and/or in the CDC-PulseNet National Database. No • The Environmental Health Specialists formal framework exists to link industrywide Network (EHS-Net) of environmental health testing to public health surveillance data. specialists and epidemiologists from local Mechanisms have been discussed that would and state health departments, FDA, FSIS, provide access to aggregated, or blinded USDA’s Food and Nutrition Service, and industry data to avoid regulatory penalties to CDC developed the National Environmental individual companies. Assessment Reporting System (NEARS) to systematically monitor and evaluate To ensure technical competence and the root causes of foodborne illness outbreaks, ability to generate reliable data, food testing including contributing risk factors and laboratories within FDA and FSIS maintain environmental antecedents. This system is accreditation in the International Organization cross-referenced with NORS and collects for Standardization/International information from detailed environmental Electrotechnical Commission 17025 assessments on factors contributing to the standard—the main international standard outbreak and the underlying conditions that used by testing and calibration laboratories. led to it. The information collected through Additionally, FDA is leading an effort to NEARS can inform hypothesis generation bring state human and animal food testing about antecedents to foodborne illness laboratories into International Organization for outbreaks and strengthen the ability of food- Standardization/International Electrotechnical control authorities to formulate and evaluate Commission 17025 accreditation to enhance the effectiveness of food-safety actions. efforts to protect the food supply. Data 24 2020 | Guidelines for Foodborne Disease Outbreak Response
1 1.3 Enhanced U.S. Foodborne Illness Surveillance Systems
generated by accredited laboratories will be Laboratory accreditation also will assist state made available for consideration during FDA manufactured food-regulatory programs in enforcement actions, as well as for surveillance achieving conformance with the Manufactured purposes and during local, state, or federal Food Regulatory Program Standards. response to foodborne illness outbreaks.
1.4 Foodborne Illness Outbreak Response and System Change
ILLNESS OUTBREAK RESPONSE 1.4.1 Although foodborne illness with specific reference to coordination of surveillance and response are rooted multijurisdictional outbreaks investigations in individual states’ laws, the growing and development of performance indicators trend in multistate outbreaks associated to measure the effectiveness of surveillance with widely distributed foods requires activities. The Second Edition of the increasing standardization of methods, Guidelines was published in 2014. THE EVOLVING CHALLENGE OF FOODBORNE CHALLENGE OF FOODBORNE THE EVOLVING integration of activities, and federal support and oversight. In response to the During this time, CDC began providing emergence of E. coli O157:H7 and other dedicated funding to support state-level foodborne pathogens during the 1990s, CDC foodborne illness outbreak response developed the active surveillance network through Epidemiology and Laboratory FoodNet, with funding assistance from Capacity cooperative agreements. This led FSIS and FDA, to conduct comprehensive to development of several CDC programs: surveillance of diagnosed illnesses within OutbreakNet, CDC’s Foodborne Diseases defined populations to assess and monitor Centers for Outbreak Response Enhancement trends in the burden of illness associated (FoodCORE), and the Integrated Food Safety with specific agents. Simultaneously, CDC Centers of Excellence and OutbreakNet established the national molecular subtyping Enhanced (OBNE). The CDC Integrated Food network PulseNet to improve laboratory-based Safety Centers of Excellence were created by surveillance for bacterial pathogens routinely FSMA. These programs are intended to work detected by clinical laboratories. PulseNet together to enhance the development and increased detection of multistate outbreaks, evaluation of foodborne illness surveillance and FoodNet provided a framework to and outbreak response activities across the interpret the impact of food system changes in United States. response to improved outbreak detection and In conjunction with CDC’s investments in regulatory activity. the performance of public health agencies, In 2005, CIFOR was established to identify FDA has used additional resources provided barriers to effective surveillance and by FSMA to develop a network of Rapid investigation of foodborne illnesses and Response Teams (RRT) to enhance outbreaks. One of the first CIFOR projects coordination between public health and was to develop guidelines for outbreak food-regulatory agencies at the state level and detection and response. The First Edition of formed a Coordinated Outbreak Response the CIFOR Guidelines, published in 2009, and Evaluation (CORE) Network to centralize established model practices for foodborne coordination of outbreak response activities disease surveillance at local and state levels, within FDA. FSIS has developed parallel outbreak response capacity (Chapter 3). 2020 | Guidelines for Foodborne Disease Outbreak Response 25
1.4 Foodborne Illness Outbreak Response and System Change 1 ILLNESS OUTBREAK RESPONSE THE EVOLVING CHALLENGE OF FOODBORNE
With a stated goal of building an Integrated systems. They enable FDA and its food- Food Safety System, FDA established the safety partners, to focus on preventing food- Partnership for Food Protection in 2008, safety problems and to address food-safety bringing together local, state, territorial, tribal, risks more rapidly when they are identified. and federal representatives with expertise in FSMA and its associated regulations grant food; feed; epidemiology; laboratory; and FDA substantial new authority to protect animal, environmental, and public health. The food all along the farm-to-fork line, covering Partnership for Food Protection (PFP) brings the preventive controls, inspections, laboratory collective expertise of the above stakeholders testing, product tracing, mandatory recall to work on projects that enhance human and authority, importer accountability, authority animal food safety in the United States. to deny entry to the U.S. market, state and local capacity building, and other areas. Coordination of activities on the federal level is accomplished through mutual liaisons • Since enactment of its Pathogen Reduction, between agencies, and joint participation in Hazard Analysis and Critical Control Point the Intergovernment Food Safety Analytics Systems rule to reduce risks associated Collaboration (IFSAC) which seeks to improve with meat and poultry in 1996, FSIS has the use of outbreak surveillance in foodborne continued to address food-safety hazards. illness attribution models and thus better guide In 2011, FSIS established raw poultry food-safety regulation. Chapter 3 details the performance standards for Campylobacter and agencies currently involved in foodborne illness updated existing ones for Salmonella. In 2012, outbreak response, along with their respective FSIS added six non-O157 STEC serogroups roles and responsibilities. Issues posed in the as “adulterants” in raw beef. In 2015, after response to multijurisdictional outbreaks are agency investigators noted they often were discussed in Chapter 7. impeded in efforts to trace ground beef to its source during outbreak investigations and 1.4.2 Food-safety standards are changing in response to STEC-positive sample results, to better control food-safety risks FSIS required its regulated establishments identified by foodborne illness outbreak and retail stores to maintain detailed records investigations. Both industry-driven to identify all ground-beef source materials. standards (e.g., from the Global Food Safety Initiative, https://www.mygfsi.com/about-us/ In summary, the foods we eat and the processes about-gfsi/what-is-gfsi.html) and government- by which they are produced, distributed, and driven regulatory requirements are being prepared; the means for diagnosing illness and updated to identify and manage food-safety detecting outbreaks; the methods whereby hazards more rapidly. Examples of noteworthy outbreaks are investigated; and the response regulatory changes in the United States include of government and private partners are always changing. The following chapters provide • The 2011 FSMA—the first major reform updated guidance to responders with these of the FDA’s food-safety authority since the changes in mind. The final chapter (Chapter 8) 1938 enactment of the Food, Drug, and provides and references metrics for evaluating Cosmetic Act. Since the Second Edition of an agency’s progress toward optimizing its the CIFOR Guidelines, some key provisions response to foodborne illness outbreaks. of FSMA have been rolled out in seven federal regulations (Chapter 2), which provide FDA with additional legal authorities and resources to strengthen food-safety 26 2020 | Guidelines for Foodborne Disease Outbreak Response
1 References
1 Scallan E, Hoekstra RM, Angulo FJ, Tauxe RV, 11 Gould L, Kline J, Monahan C, Vierk K. Outbreaks of Widdowson MA, Roy SL, et al. Foodborne illness disease associated with food imported into the United acquired in the United States—major pathogens. States, 1996–2014. Emerg Infect Dis. 2017;23:525–8. Emerg Infect Dis. 2011;17:7–15. 12 Taylor DN, Wachsmuth IK, Shangkuan YH, Schmidt 2 Scallan E, Griffin PM, Angulo FJ, Tauxe RV, Hoekstra EV, Barrett TJ, Schrader JS, et al. Salmonellosis RM. Foodborne illness acquired in the United States— associated with marijuana: a multistate outbreak unspecified agents. Emerg Infect Dis. 2011;17:16–22. traced by plasmid fingerprinting. N Engl J Med. 3 Tack DM, Marder EP, Griffin PM, Cieslak PR, Dunn 1982;306:1249–53. J, Hurd S, et al. Preliminary incidence and trends 13 Colorado Integrated Food Safety Center of of infections with pathogens transmitted commonly Excellence. County fair chocolate scare: a foodborne through food—Foodborne Diseases Active Surveillance outbreak investigation case study. www.ucdenver.edu/
ILLNESS OUTBREAK RESPONSE Network, 10 U.S. sites, 2015–2018. MMWR Morb academics/colleges/PublicHealth/research/centers/ Mortal Wkly Rep. 2019;68:369–73. foodsafety/Pages/Training.aspx 4 Centers for Disease Control and Prevention. 14 U.S. Department of Agriculture, National Surveillance for foodborne disease outbreaks, United Agricultural Statistics Service. 2017 United States States, 2017, annual report. https://www.cdc.gov/ census of agriculture. Summary and state data. fdoss/pdf/2017_FoodBorneOutbreaks_508.pdf Volume 1. Geographic area series. Part 51. AC- THE EVOLVING CHALLENGE OF FOODBORNE CHALLENGE OF FOODBORNE THE EVOLVING 5 Hoffmann S, Maculloch B, Batz M. Economic burden 17-A-51. https://www.nass.usda.gov/Publications/ of major foodborne illnesses acquired in the United AgCensus/2017/index.php States, EIB-140, U.S. Department of Agriculture, 15 Food Safety Modernization Act. Pub. L. No. 111–353, Economic Research Service, May 2015 124 Stat. 3885 (2011). https://www.ers.usda.gov/publications/pub- 16 U.S. Department of Agriculture, Economic Research details/?pubid=43987 Service. Food-away-from-home. https://www. 6 Bottichio L, Keaton A, Thomas D, Fulton T, Tiffany ers.usda.gov/topics/food-choices-health/food- A, Frick A, Mattioli M, Kahler A, Murphy J, Otto consumption-demand/food-away-from-home M, Tesfai A, Fields A, Kline K, Fiddner J, Higa J, 17 Dewey-Mattia D, Manikonda K, Hall AJ, Wise Barnes A, Arroyo F, Salvatierra A, Holland A, Taylor ME, Crowe SJ. Surveillance for Foodborne Disease W, Nash J, Morawski BM, Correll S, Hinnenkamp R, Outbreaks — United States, 2009–2015. MMWR Havens J, Patel K, Schroeder MN, Gladney L, Martin Surveill Summ 2018;67(No. SS-10):1–11. DOI: H, Whitlock L, Dowell N, Newhart C, Watkins LF, http://dx.doi.org/10.15585/mmwr.ss6710a1 Hill V, Lance S, Harris S, Wise M, Williams I, Basler C, Gieraltowski L. Shiga Toxin-Producing E. coli 18 Jones TF, Angulo FJ. Eating in restaurants: a risk Infections Associated with Romaine Lettuce - United factor for foodborne disease? Clin Infect Dis. States, 2018. Clin Infect Dis. 2019 Dec 9. pii: ciz1182. 2006;43:1324–8. doi: 10.1093/cid/ciz1182. [Epub ahead of print] 18 Food and Drug Administration. FDA Food Code. 7 Nielsen Insights. Celebrating National Salad Month https://www.fda.gov/food/guidanceregulation/ amid romaine lettuce worries. 05-09-2018. https:// retailfoodprotection/foodcode/default.htm www.nielsen.com/us/en/insights/article/2018/ 19 Food and Drug Administration. Retail Food celebrating-national-salad-month-amid-romaine- Risk Factor Study. https://www.fda.gov/Food/ lettuce-worries GuidanceRegulation/RetailFoodProtection/ 8 Centers for Disease Control and Prevention. Outbreak FoodborneIllnessRiskFactorReduction of E. coli infections linked to romaine lettuce. Final 20 Food and Drug Administration. FDA report on the update. Food-safety alert. https://www.cdc.gov/ occurrence of foodborne illness risk factors in fast ecoli/2018/o157h7-11-18/index.html food and full-service restaurants, 2013–2014. 9 Bartsch SM, Asti L, Nyathi S, Spiker ML, Lee BY. https://www.fda.gov/media/117509/download Estimated cost to a restaurant of a foodborne illness outbreak. Public Health Rep. 2018;133:274–86. 10 U.S. Department of Agriculture, Economic Research Service. Food availability (Per Capita) Data System. https://www.ers.usda.gov/data-products/food- availability-per-capita-data-system CHAPTER 2
Legal Preparedness for the Surveillance, Investigation, and Control of Foodborne Illness Outbreaks
CHAPTER SUMMARY POINTS • The authority to identify, investigate, and control foodborne illness outbreaks is shared across local, state, and federal, governments and requires ongoing cooperation. Legal preparedness is the assurance that agencies and jurisdictions are equipped with sufficient legal authorities to conduct effective disease surveillance and control and have staff trained to use these authorities. • Local and state statutes and regulations authorize the reporting and investigation of foodborne illnesses. The communicable disease control regulatory process is often used to specify diseases and conditions to be reported, the information to be reported, and the process for making a report. State laws and regulations also address the confidentiality of disease reports and enforcement of reporting requirements. • Local and state agencies need to regularly access confidential records when investigating reports of foodborne illness. They must navigate differing local, state, and federal legal authorities and requirements as they seek to access and share information with other government agencies and respond to media inquiries. • Shared goals of the public and private sectors are to prevent as many outbreaks as possible and to mitigate those that occur. In the public sector, local, state, and federal agencies accomplish those goals by working independently and together to exercise their legal authorities to, among other things, inspect, seize or destroy foods, and close establishments. • Although reporting, surveillance, and mitigation of foodborne illness outbreaks are well established in local, state, and federal law, issues continue to arise that demonstrate differences among state and federal laws and the need for ongoing communication and collaboration among state, local, and federal officials who are united in the common goal of protecting the public’s health. • During foodborne illness investigations, public officials may find issues that require the initiation of administrative actions or even civil or criminal proceedings. Data collected during a foodborne illness investigation can become the basis for further action by local, state, and federal agencies.
URLs and email addresses in this chapter are valid as of July 3, 2019. 28 Council to Improve Foodborne Outbreak Response
2.0 Introduction
2.0.1 Understanding and appropriately health and preventing disease by leveraging using law is a fundamental part of legal authorities across local, state, and federal
2 protecting the public’s health from jurisdictions. foodborne illness. Local, state, and federal government agencies share the authority to 2.0.2 This chapter addresses legal identify, investigate, and control foodborne preparedness in the various aspects of illness outbreaks, but each level of government foodborne illness outbreak surveillance and each agency within it has specific roles, and control—reporting, surveillance, responsibilities, and legal authorities. The investigation, mitigation, and prevention— success of a public agency’s efforts to combat through the perspective of local, state, foodborne illness also greatly depends on its and federal agencies. It also discusses critical cooperation and communication with multiple issues that arise during outbreak investigations, parties in the food, agriculture, healthcare, such as confidentiality of data and use of and laboratory sectors. Ultimately, the goal is public health investigations as the basis for to become more effective at protecting public regulatory actions or criminal prosecutions. LEGAL PREPAREDNESS FOR THE FOR THE LEGAL PREPAREDNESS
OF FOODBORNE ILLNESS OUTBREAK 2.1 Public Health Legal Preparedness
Legal preparedness is an indispensable part processing information to identify and mitigate of a comprehensive preparedness plan for the source of an outbreak while protecting SURVEILLANCE, INVESTIGATION, AND CONTROL AND CONTROL SURVEILLANCE, INVESTIGATION, public health threats. The Centers for Disease confidentiality and preserving rights. Control and Prevention (CDC) defines public health legal preparedness as the attainment by 2.1.1 Legal preparedness within the a public health agency or system of specified context of surveillance, investigation, and legal benchmarks or standards of preparedness control of foodborne illness outbreaks for specified public health concerns (1). requires state and local officials to ensure Public health legal preparedness has four core their agencies and jurisdictions have the elements: following:
• Laws and legal authorities; • Laws and legal authorities needed to conduct all functions essential to effective • Competency in understanding and using law; surveillance, investigation, and control • Coordination across sectors and jurisdictions (e.g., reporting, enforcement, prevention, in the implementation of law; and mitigation, investigation, and regulation). • Information about best practices in using law • Trained professional staff with demonstrated for public health purposes. competency in applying relevant laws.
These core elements apply to all areas of • Mutual aid agreements or memoranda public health, especially in the areas of food of understanding in place to facilitate safety and foodborne illness outbreaks. Because investigation and response across the U.S. food system is highly complex, jurisdictions and agencies. public health, food, and agriculture officials • Access to information about model practices responding to foodborne illness outbreaks in using relevant legal authorities and face the challenge of rapidly gathering and applying them. 2020 | Guidelines for Foodborne Disease Outbreak Response 29
2.1 Public Health Legal Preparedness
Box 2.1. Partnering with Your Agency’s Attorney (2) 2 To prepare for an outbreak: • Meet with your agency’s attorney to discuss specific legal authority and responsibilities contained in OF FOODBORNE ILLNESS OUTBREAK SURVEILLANCE, INVESTIGATION, AND CONTROL LEGAL PREPAREDNESS FOR THE local, state, and federal law relative to disease reporting, investigations, and food-regulatory actions (e.g., permit suspension and closure, employee restrictions). • Identify outbreak settings or conditions for which legal assistance might be needed. Outbreak settings or conditions for which legal assistance might be needed: • There is a reasonable chance the public’s health is or might be threatened without specific public health intervention. • Your ability and authority to address the situation is unclear. • The event or circumstance could expose your agency or organization to potential liability, or political pressure. In an outbreak situation in which you might need legal assistance: • Contact your agency’s attorney as soon as possible for legal input. • Be candid and open; give all the facts—don’t allow for surprises. • Proactively include your agency’s attorney in discussions rather than seeking ratification of decisions later. If you do not understand or you disagree with the advice provided by your agency’s attorney, ask for clarification or discuss other options with him or her rather than requesting different advice from another attorney.
The adequacy of local and state legal regulatory requirements and the way these preparedness for foodborne illness outbreaks requirements might affect their internal also should be evaluated regularly through policies on sharing information (3). Where exercises and after-action reviews from actual possible, both public and private entities should outbreaks. be included in foodborne illness exercises to test their understanding of their legal authority As part of ensuring their jurisdictions’ legal and duties related to outbreaks. preparedness, local and state officials should consult with their legal counsel (Box 2.1) 2.1.2 As government entities, public health, and with counterparts in other government food, and agriculture agencies operate agencies that have authority relevant to within the context of the U.S. Constitution, ensuring successful surveillance and control state constitutions, federal and state of foodborne illness outbreaks. These include statutes and regulations, local charters food and agriculture regulatory and law and ordinances, court decisions, and more. enforcement agencies, legal counsel to local Thus, these agencies are empowered and and state governments, and local and state limited within this context and must navigate courts and court administrators. the country’s foundational legal principles, i.e.,
Private organizations also must be aware • A system of checks and balances. Public of their legal duties regarding food safety health, food, and agriculture agencies belong and disease reporting). These duties vary by to the Executive Branch and are broadly state. Relevant private entities include private charged with implementing laws enacted by laboratories, food firms, hospitals, and other the legislature and interpreted by the courts. health institution food services. Food-industry • Federalism. The U.S. Constitution entities should be prepared to address both enumerates specified powers for the federal 30 Council to Improve Foodborne Outbreak Response
2.1 Public Health Legal Preparedness
government and reserves other powers In general, these parameters apply to state and to the states (tribes are autonomous or local public health agencies’ surveillance and
2 sovereign bodies). In addition, state and local control of foodborne illness outbreaks. Those governments possess inherent police powers activities, however, are further authorized to protect the health and safety of the public. and conditioned by the statutes, regulations, • Protection for civil liberties and property ordinances, and case law of the individual rights. The Fourth, Fifth, and Fourteenth jurisdictions. Some of these laws relate Amendments protect citizens from specifically to foodborne illnesses, but in unreasonable searches and from deprivation many jurisdictions, public health agencies rely of life, liberty, and private property without on laws (state statutes and local ordinances) due process of law. State constitutions, that authorize surveillance for infectious statutory law, and court rulings provide diseases generally. additional protections relevant to the 2.1.4 CDC operates under congressionally conduct of foodborne illness surveillance enacted statutory law and, especially in and operations by public agencies. LEGAL PREPAREDNESS FOR THE FOR THE LEGAL PREPAREDNESS the case of foodborne illness surveillance, 2.1.3 The legal authority supporting local under provisions of the Public Health OF FOODBORNE ILLNESS OUTBREAK and state public health agencies’ role Service Act (5). CDC is not authorized to in the protection and promotion of the mandate reporting of diseases and conditions public’s health stems from constitutional, by state and local governments or by private statutory, regulatory, and judicial case law, entities. However, states do mandate reporting
SURVEILLANCE, INVESTIGATION, AND CONTROL AND CONTROL SURVEILLANCE, INVESTIGATION, as well as from the general police powers. pursuant to state laws. However, these powers are not unlimited. Among many other provisions, the Public Important legal parameters for public health Health Service Act authorizes CDC to gather authority and practice were articulated in the data on nationally notifiable diseases pursuant foundational 1905 U.S. Supreme Court ruling to guidelines CDC develops in partnership in Jacobson v. Massachusetts (4): with state and local public health agencies and • With compelling reason, individual liberties professional societies. Many of these data come can be subordinated to the well-being of the from state and local public health agencies. community. CDC partners with the Council of State and Territorial Epidemiologists to establish (and • The police power of the state authorizes modify as needed) case definitions for diseases. issuance and enforcement of reasonable These guidelines and case definitions, however, regulations to protect the health of the are not legally binding. States have the community. autonomy to adopt these Council of State and • Courts defer to the authority that legislative Territorial Epidemiologists–developed case bodies give to public health agencies if that definitions or develop their own definitions authority is exercised on the basis of for use in their states. CDC does not collect persuasive public health and medical personal identifiers on routine surveillance data evidence. that it receives from public health departments.
• Public health agencies cannot act in an The Public Health Service Act also authorizes arbitrary manner or pose unreasonable risks CDC to perform laboratory tests on specimens for harm. received from state and local governments (and from other sources) to identify pathogens, confirm serotypes or molecular subtypes, 2020 | Guidelines for Foodborne Disease Outbreak Response 31
2.1 Public Health Legal Preparedness perform diagnostic assays, and report Additionally, CDC may participate in an findings to appropriate state and local health outbreak investigation within a state if 2 departments. Virtually all enteric illness invited by the state. Multistate investigations specimens tested in CDC laboratories are are typically led by CDC or the state health OF FOODBORNE ILLNESS OUTBREAK SURVEILLANCE, INVESTIGATION, AND CONTROL LEGAL PREPAREDNESS FOR THE initially tested in state or local public health department where most of the cases occurred. laboratories.
2.2 Legal Framework for Surveillance and Disease Reporting
Investigation of enteric illnesses to determine • Surveillance reports for enteric pathogens; the source of exposure, risk factors for infection, • Requests for antitoxin for botulism; and contacts of a person with a contagious disease is usually considered part of surveillance • Reports of food poisoning or gastrointestinal and disease control activities authorized by illness in individuals or defined groups, such local and state statutes. Likewise, state and local as diarrhea and vomiting among residents authority to mandate disease reports arises of a nursing home or hospital, attendees at from state law. The regulatory process is used to schools or childcare centers, or attendees at a specify diseases and conditions to be reported, work-related meeting; the information to be reported about a case, • Reports to poison control centers; and the process for making a report. State laws • Reports of enteric illness suspected of being and regulations also address the confidentiality caused intentionally; of disease reports and enforcement of reporting requirements (Box 2.2). • Complaints of suspected foodborne illness or alleged exposure to contaminated, Box 2.2. Communication with adulterated, or improperly cooked food Laboratories and Hospitals purchased from stores or in restaurants and reported voluntarily by the public; Ongoing communication arrangements should be established with national or regional • Syndromic surveillance using de-identified commercial and clinical laboratories to ensure emergency department or pharmacy data; that the investigating agencies receive results and for relevant cases, even when those tests are conducted out of state. Similar communication • Reports directly from the food industry of channels also should be established with in- consumer complaints of illness. state and out-of-state hospitals that serve a population within the community affected by 2.2.2 The state legislature generally gives the outbreak. broad statutory authority to the state health department to collect information and to require reports of diseases, conditions, and 2.2.1 Local and state health agencies learn outbreaks of public health importance. about foodborne illnesses through a variety Generally, the state legislature also gives the of sources that vary in reliability and state health department the authority to adopt traceability. As discussed further in Chapter 4, rules or regulations that specify which diseases these include or conditions must be reported, who must • Reports through the state’s mandatory report them, and how to report (Table 2.1). disease and conditions reporting system; 32 Council to Improve Foodborne Outbreak Response
2.2 Legal Framework for Surveillance and Disease Reporting
The list of reportable diseases and conditions In addition to broad authority, states typically and laboratory findings is maintained and have several disease-specific statutes, such as
2 updated by epidemiologists and health officers those for human immunodeficiency virus/ in state and local agencies, with review and acquired immunodeficiency syndrome, approval by the body overseeing the health tuberculosis, and vaccine-preventable diseases, department. which authorize surveillance and control activities. All states also have statutes addressing reporting and response to bioterrorism incidents.
Table 2.1. Reporting Processes Typically Specified by Statutes and Regulations PROCESS REQUIREMENT COMMENT Sources of The usual sources of mandatory reports are The source of a reports • Laboratories report does not Hospital-based laboratories; affect the legal status
LEGAL PREPAREDNESS FOR THE FOR THE LEGAL PREPAREDNESS Clinical laboratories; of the information; National or regional commercial referral laboratories; if it is required
OF FOODBORNE ILLNESS OUTBREAK Local or state health department laboratories; and information, it is CDC laboratories; protected by statutes • Health care institutions and regulations. Hospitals (e.g., hospitalized patients reported by infection control practitioners); Conversely, reports
SURVEILLANCE, INVESTIGATION, AND CONTROL AND CONTROL SURVEILLANCE, INVESTIGATION, Emergency departments; and to the agency of Long-term–care facilities or nursing homes; an illness not listed • Physicians; as a reportable • Schools and childcare centers; condition might • Food establishments (e.g., restaurants); and Other state health not be subject to departments. disease surveillance regulations and confidentiality protections.
Time frame Statutes and regulations usually specify the following aspects of and content disease reports: of reports • Time frame for reporting (e.g., within 7 days after diagnosis, within 24 hours after diagnosis, immediately); and • Information to be reported (e.g., diagnosis; personal identifying and locating information; date of onset or diagnosis regardless of whether the case is suspected or confirmed).
Reporting A state or municipality can use a variety of methods for reporting. methods Specifics vary from one locale to another. These methods include • Internet-based, highly secure disease reporting to websites maintained by state or local public health agencies; • Reports sent by email; • Automatic electronic submission through health information exchange; • Telephone; and/or • Hard copy (fax or mail). 2020 | Guidelines for Foodborne Disease Outbreak Response 33
2.2 Legal Framework for Surveillance and Disease Reporting
Table 2.1. Reporting Processes Typically Specified by Statutes and Regulations
Continued 2
PROCESS REQUIREMENT COMMENT OF FOODBORNE ILLNESS OUTBREAK SURVEILLANCE, INVESTIGATION, AND CONTROL LEGAL PREPAREDNESS FOR THE Required Many public health agencies have adopted regulations that require In some locales, submission laboratories to submit isolates of specific pathogens to a state or voluntary of laboratory local health department laboratory for further confirmatory and/ submission of specimens or genomic testing, such as pulsed-field gel electrophoresis and/or specimens achieves whole-genome sequencing, to improve surveillance for foodborne the same goal. disease (see also 6).When the clinical laboratory does not obtain isolates, some states require or request submission of primary clinical material or enrichment broths. The regulations often include a time frame for submission of such materials.
With the increasing development and use in clinical settings of culture-independent diagnostic tests (CIDT), which do not produce an isolate, there is growing concern that the supply of isolates
to health departments will be depleted, hindering public health surveillance activities. To address these concerns, states have begun to amend their laws. A few states have added language that gives specific submission instructions to a clinical laboratory that has used CIDT methods to make a diagnosis. Other states have expanded their list of acceptable materials for submission beyond only an “isolate” to include “specimen,” “primary clinical material,” “enrichment broths,” and other alternative materials to submit if the preferred isolate is not available. States may continue to amend their disease reporting laws, in various ways to fit the needs of the jurisdiction, as CIDT continues to develop for a broader number of pathogens.
2.2.3 Reliable reporting by persons and and penalty provisions. Depending on the institutions mandated to submit disease jurisdiction and the frequency and severity reports is the foundation of the reporting of nonreporting, sanctions can range from system. When enteric illnesses are not notification to a state licensure board to civil reported, a foodborne illness outbreak fines and/or criminal penalties. may be missed. Because of the problem of nonreporting, redundant reporting systems Reporting may be difficult to enforce with a have been established to ensure a case will be laboratory or healthcare provider outside an reported (e.g., a Salmonella infection might be agency’s jurisdiction, such as when a state seeks separately reported by physicians, laboratories, reports from a reference laboratory located in and healthcare institutions). Because health another state. In that situation, lack of reporting agencies want to encourage compliance, usually results from misunderstanding of how ongoing education and communication with to report. Occasionally a laboratory will assert persons and institutions mandated to report that it complies with requirements of the public is imperative to reinforce the importance of health agency in the state in which it is physically reporting requirements. located—which might or might not require reporting of the specific disease, infection, or Education is the preferred method to obtain laboratory result. Again, ongoing communication reporting compliance, but when violations with the parties required to report and arise, statutes and regulations mandating coordination with the state health agency in the disease reporting also contain enforcement parties’ home state can improve reporting. 34 Council to Improve Foodborne Outbreak Response
2.3 Protection of Confidentiality and Authority to Access Records
State and local health agencies need to 2.3.1 HIPAA and its associated regulations 2 regularly access confidential records when limit access to a person’s protected health
investigating reports of foodborne illness. information (PHI) (7, 8). PHI is information However, when doing so, federal and state that can be used to individually identify a laws mandate the protection of confidential person through demographic data, diagnosis, personal information during these public treatment, or payment for treatment (9). health investigations. Important exceptions to HIPAA allow public Typically, the broad authority to conduct health and other government agencies to surveillance includes authority to investigate access PHI, including and control diseases of public health significance, including review of relevant and • Required by Law. Entities covered by pertinent medical and laboratory records HIPAA (e.g., doctors, healthcare plans) may and reports (i.e., information that is not use and disclose PHI without individual LEGAL PREPAREDNESS FOR THE FOR THE LEGAL PREPAREDNESS necessarily included in the basic case report). authorization if required by law (e.g., statute, Although medical and laboratory staff might regulation, or court order). OF FOODBORNE ILLNESS OUTBREAK be concerned about potential violations of • Public Health Activities. Covered federal Health Insurance Portability and entities may disclose PHI under several Accountability Act (HIPAA) (7) and state circumstances related to public health privacy laws in releasing records, exceptions activities, including SURVEILLANCE, INVESTIGATION, AND CONTROL AND CONTROL SURVEILLANCE, INVESTIGATION, for public health and other government agencies allow access to records. Consulting Public health authorities authorized by with an agency attorney is advisable whenever law to collect or receive information for questions or concerns arise about accessing or preventing or controlling disease, injury, disclosing confidential information (Box 2.3). or disability;
Box 2.3. Prepare for Questions Persons who might have been exposed about Authority to Access to or contracted a communicable disease Information when notification is authorized by law; or Staff in an organization that might be required Entities subject to Food and Drug to provide information to local, state, and Administration (FDA) regulation for federal officials about foodborne illnesses purposes such as tracking products or and outbreaks might not be familiar with the product recalls. authority of government officials to access individually identifying and other privacy- These exceptions in effect authorize a covered restricted information under certain provisions entity (e.g., doctor) to disclose otherwise of state and/or federal law. confidential PHI. Explaining these exceptions These organizations might include those (e.g., to physicians or their staff often results in better childcare, elder care) that, depending on state compliance with reporting requirements. law, might not have routine interaction with HIPAA does not restrict the use of de-identified disease reporting and outbreak investigation information, which does not identify a person systems. or provide a basis for identification 10( ). Consult with your agency’s attorney to prepare memorandum or information sheets tailored to different types of organizations that specify state and federal authority to access information. 2020 | Guidelines for Foodborne Disease Outbreak Response 35
2.3 Protection of Confidentiality and Authority to Access Records
2.3.2 Local and state health agency 2.3.3 A public health agency may be 2 staff must know the requirements of restricted from sharing PPI with other OF FOODBORNE ILLNESS OUTBREAK SURVEILLANCE, INVESTIGATION, AND CONTROL LEGAL PREPAREDNESS FOR THE their freedom of information laws and government agencies without the consent the exemptions from them. Personal of the reported person. However, these identifying information (PII) (e.g., name, restrictions are subject to several exceptions: age, sex, race, ethnicity, residence, or date of diagnosis) in disease reports and investigation • Local and state health agencies are generally records is generally confidential and exempt permitted to share information with other from disclosure in response to freedom of state, local, and federal agencies to confirm information requests. Each state can define and track cases. what it considers to be PII. The goal is to avoid • Many state statutes contain an exception for releasing data that make it possible to directly sharing information when, in the agency’s or indirectly identify the affected person if judgment, sharing is necessary to protect the released data are combined with other public health. information. When there are a large number • Virtually every state has an exception for of cases, it might be possible to release data sharing information with law enforcement other than names and residences in response to agencies for investigation of intentional freedom of information requests. When there contamination or a bioterrorism incident. are too few cases among the population of a given area, an agency might have a policy of 2.3.4 The U.S. Department of Health and not releasing data to guard against potential Human Services (DHHS), FDA, has formal- identification of an individual person. This ized arrangements for information sharing determination should be made in each instance with local and state regulatory agencies. in conjunction with agency epidemiologists, FDA provides nonpublic information to state statisticians, and attorneys. and local agencies under 20.88 agreements (12) and to certain state and local officials who In addition to potential restrictions on sharing have been commissioned by FDA (Box 2.4). PII, state laws might restrict sharing of other types of information, such as confidential • 20.88 agreements are authorized under 21 commercial information and predecisional/ CFR 20.88. 20.88 agreements allow FDA deliberative information. Furthermore, the to share certain nonpublic information federal Privacy Act can restrict the sharing of with state and local government officials. certain personal privacy information (PPI) by These agreements allow for the sharing of federal agencies (11). confidential commercial information, PPI, and predecisional information (PDI), and Occasionally a public health agency must predeliberative information but not trade respond to a media inquiry in which the media secret information. The receiving agency have learned the identity of a particular case must commit to keep this information from another source. The agency’s response to confidential 12,13( ). FDA offers several types the media inquiry must be carefully structured of 20.88 agreements: to avoid unintentional confirmation of the patient’s identity. Preparing final outbreak Single-Signature Long-Term Information investigation summary reports without any Sharing Agreements (Food and Feed, PII can hasten and simplify release of those Pharmacy Compounding, Drug Security) reports to attorneys or media. (Long-Term 20.88) allows for the sharing of nonpublic information proactively or 36 Council to Improve Foodborne Outbreak Response
2.3 Protection of Confidentiality and Authority to Access Records
on request related to food, animal food, also authorizes state or local officials to 2 cosmetics, pharmacy compounding, drug conduct inspections under the Federal Food,
security with all employees who report to Drug, and Cosmetic Act (FFDCA) (16). the signatory. 2.3.5 The U.S. Department of Agriculture Case-Specific 20.88 allows for the sharing (USDA) Food Safety and Inspection of nonpublic information related to a Service (FSIS) has a process for sharing particular incident involving an FDA- information with government partners. related industry (e.g., food, drugs, devises, FSIS Directive 2620.5 addresses “procedures biologics). A Case-Specific 20.88 can needed to share information concerning FSIS be expedited if FDA is made aware of regulated products with State or local agencies, the need for urgent processing. Each foreign government officials, and international employee who will need access to the organizations responsible for food inspection information must sign. programs and laboratories” (17). To request LEGAL PREPAREDNESS FOR THE FOR THE LEGAL PREPAREDNESS 20.88 with Associations allows for proactive outbreak-related information from FSIS, or upon request sharing of nonpublic send an email to FoodborneDiseaseReports@ OF FOODBORNE ILLNESS OUTBREAK deliberative processes and predecisional usda.gov. information only. Examples may include draft rules and/or draft guidance. Box 2.4. Cross-Jurisdiction and Cross- Sector Coordination
SURVEILLANCE, INVESTIGATION, AND CONTROL AND CONTROL SURVEILLANCE, INVESTIGATION, • Commissioning. FDA’s commissioning process enables a state or local health, Effective reporting of foodborne illness cases food, or drug official to be commissioned hinges on coordinated reporting across as an officer of DHHS (14). Commissioned jurisdictions (e.g., local, state, tribal, and federal officials may receive nonpublic information governments) and across sectors (e.g., healthcare and public health). Local and state health solely for the purpose of their work on behalf officials should periodically assess the need of FDA as a commissioned official. They for memoranda of agreement (or other legal may generally disclose that information to agreements) with partners in other jurisdictions other FDA-commissioned officials (in their and sectors to ensure timely and effective capacity as FDA commissioned officials) reporting. CDC has created several resources for and FDA employees (15). Such information assessing and improving cross-jurisdictional and remains FDA information. Commissioning cross-sector coordination (18,19).
2.4 Legal Framework to Prevent or Mitigate Foodborne Illness Outbreaks
Shared goals of the public and private sectors previously were thought to be sporadic and are to prevent as many outbreaks as possible to identify and address implicated foods and and to mitigate those that do occur. Changes in sources. However, with continued globalization technology and food production have brought of food-production industries, more multistate opportunities and challenges. Improvements and international foodborne illness outbreaks in laboratory and communication technologies are being discovered, thus expanding the have enabled agencies to link cases that focus of outbreak investigations and control 2020 | Guidelines for Foodborne Disease Outbreak Response 37
2.4 Legal Framework to Prevent or Mitigate Foodborne Illness Outbreaks
. measures. This section reviews the roles of Voluntary compliance through the 2 local, state, and federal, agencies and the legal issuance of inspectional observations, OF FOODBORNE ILLNESS OUTBREAK SURVEILLANCE, INVESTIGATION, AND CONTROL LEGAL PREPAREDNESS FOR THE authorities empowering them to act. untitled letters and warning letters;
. 2.4.1 U.S. law authorizes several federal Civil action, such as an injunction to agencies to undertake regulatory and prevent future violations of the nonregulatory actions over food safety at FFDCA (e.g., continued distribution various stages on the continuum of food of adulterated food); production, importation, processing, . Seizure action to remove specific lots transportation, storage, and sale. Agencies of adulterated food; regulating food have the authority to inspect, . Mandatory recall of food that presents recall, and seize unsafe foods. All agencies a certain risk to public health; coordinate and collaborate with states and localities in the prevention of foodborne . Criminal action against an individual or illness and in multistate investigations. This company that violates the FFDCA such section focuses on CDC, FDA, USDA, and the as by causing food to become adulterated Environmental Protection Agency (EPA) and by inadequate processing and handling; their legal authority related to food safety (see . Administrative detention of certain Chapter 3 for each federal agency’s roles and food for up to 30 days; and resources). . Suspension of the registration of a • DHHS, CDC facility so that food from the facility The Public Health Service Act (5) authorizes cannot be introduced into commerce. CDC to identify and monitor foodborne In some circumstances, FDA’s authority under diseases and to investigate foodborne the FFDCA is limited by the requirement that illness outbreaks in coordination with local food be in interstate commerce. However, and state health agencies. CDC can lead under both the FFDCA and the Public Health investigations into multistate foodborne Service Act, FDA can regulate intrastate illness outbreaks and, when invited, work in commerce in certain instances. Even when partnership with the state where the most authority exists for FDA action, relying on cases have occurred. state agency action might be faster when state • DHHS, FDA authorities are more expansive or flexible than The FFDCA (16) authorizes FDA to regulate FDA’s authorities. domestic and imported food, except meat, Amendments to the FFDCA in 2007 require poultry, and processed egg products (i.e., registered food facilities that manufacture, frozen, dried, and liquid eggs), which are process, pack, or hold food for human or regulated by USDA. animal consumption in the United States to FFDCA report to FDA’s Reportable Food Registry The primary legislation by which FDA when a reasonable probability exists that the exercises authority over food is the use of, or exposure to, an item of food will FFDCA. A goal of FDA is to prevent cause serious adverse health consequences or contamination of food products before death to humans or animals (20). FFDCA was distribution. FFDCA also empowers FDA further amended in 2011 by the Food Safety to pursue: Modernization Act (21). 38 Council to Improve Foodborne Outbreak Response
2.4 Legal Framework to Prevent or Mitigate Foodborne Illness Outbreaks
FDA Food Safety Modernization Act regarding implementation of FSMA and its 2 The FDA Food Safety Modernization rules. The FDA website (https://www.fda.gov/
Act (FSMA), signed into law in January Food/GuidanceRegulation/FSMA/default. 2011, amended the FFDCA to enhance htm) provides details about the law, rules and the federal government’s ability to prevent updates on the status of FSMA implementation. and respond to contamination in the food supply (21). The law addresses prevention, FDA Food Code inspection, compliance, and response Although the FDA Food Code is not a activities. federal law or regulation, this model code may be adopted or adapted by states, FDA, the agency primarily responsible tribes, and localities as the basis for their for implementing FSMA, has developed jurisdictions’ food-safety rules for retail a series of rules and guidance documents and food-service establishments (e.g., to address the law’s requirements. As restaurants, grocery stores, institutions) LEGAL PREPAREDNESS FOR THE FOR THE LEGAL PREPAREDNESS of April 2018, FDA has finalized the (37). The Food Code assists jurisdictions following rules: in updating their rules to be consistent OF FOODBORNE ILLNESS OUTBREAK . Current Good Manufacturing Practice, with federal food-safety policy, although Hazard Analysis, and Risk-Based each jurisdiction undergoes its own Preventive Controls for Human Food rulemaking process to adapt the code (22,23). to fit the jurisdiction’s legal framework. SURVEILLANCE, INVESTIGATION, AND CONTROL AND CONTROL SURVEILLANCE, INVESTIGATION, Currently, FDA revises the Food Code . Current Good Manufacturing Practice, every 4 years. Hazard Analysis, and Risk-Based Preventive Controls for Food for • USDA, FSIS Animals (24,25). USDA-FSIS has the legal authority to . Foreign Supplier Verification Programs regulate meat, poultry, and egg products on (26,27). the basis of the following statutes: . Mitigation Strategies to Protect Food Federal Meat Inspection Act (38). Against Intentional Adulteration (28,29). Poultry Products Inspection Act (39). . Sanitary Transportation of Human and Egg Products Inspection Act (40). Animal Food (30,31). . Standards for the Growing, Harvesting, Each of these Acts is intended to protect the Packing, and Holding of Produce for health and welfare of the consuming public by Human Consumption (32,33). preventing the introduction of adulterated or misbranded meat, poultry, or egg products in . Accredited Third-Party Certification interstate commerce. In addition, in states that (34,35). do not have meat or poultry inspection pro- FDA has also implemented a Voluntary grams “at least equal to” the federal programs, Qualified Importer Program 36( ). It is a Federal Meat Inspection Act and Poultry fee-based, voluntary program that provides Products Inspection Act provide for federal importers meeting specified criteria with regulation and inspection of wholly intrastate expedited review and import entry of human operations and transactions to the same extent and animal foods. In addition to rules, FDA as if such operations and transactions were has issued multiple guidance documents conducted in interstate or foreign commerce. 2020 | Guidelines for Foodborne Disease Outbreak Response 39
2.4 Legal Framework to Prevent or Mitigate Foodborne Illness Outbreaks
In carrying out its duties under these Acts, (e.g., no specific brand name of product 2 USDA-FSIS may pursue the following actions: identified), then USDA-FSIS may issue a OF FOODBORNE ILLNESS OUTBREAK SURVEILLANCE, INVESTIGATION, AND CONTROL LEGAL PREPAREDNESS FOR THE public health alert (41). Regulatory action for federally inspected facilities, such as retention of product, Further, depending on the evidence collected, withholding actions, and notices of and how strongly human illness is linked to a intended enforcement, suspension, USDA-FSIS-regulated product, USDA-FSIS or withdrawal; may take actions other than recommending Civil action, such as an injunction to a product recall or issuing public health alert. prevent future violations of the Acts These actions may include increasing or (e.g., continued distribution of enhancing inspection activities; increasing the adulterated or misbranded products); frequency of microbial testing; conducting a Public Health Risk Evaluation; performing an Detention and seizure action to remove in-plant Food Safety Assessment; or taking any
specific products from commerce; of the actions listed above, such as effecting a Criminal action against an individual or regulatory control action or detaining and/or company that violates the Acts; or seizing product (41).
Voluntary compliance through notices • USDA, Animal and Plant Inspection of warning. Service (APHIS) USDA-APHIS is charged with protecting Specifically, in response to a foodborne illness animal and plant resources from agriculture outbreak, if a basis exists to conclude that a pests and diseases, including those that USDA-FSIS-regulated product contains a impact public health. USDA-APHIS pathogen or is otherwise harmful to human operates under multiple statues, including health, and an outbreak investigation has identified a specific product, USDA-FSIS Animal Health Protection Act. This may recommend a product recall (41). A Act authorizes the prevention, detection, recall is a firm’s action to remove a product control, and elimination of diseases and from commerce to protect the public from pests in animals to protect animal health, consuming misbranded or adulterated public health and welfare, and economic products. Although it is a firm’s decision to and environmental concerns (42). recall a product, USDA-FSIS coordinates with the firm to ensure it has properly identified and Plant Protection Act. This Act permits removed the recalled product from commerce regulation to prevent the introduction or by verifying the effectiveness of the firm’s dissemination of plant pests in the United recall activities. USDA-FSIS also notifies the States, including certain biological control public about product recalls. organisms (43).
Alternatively, if after review of investigative • EPA findings, a basis exists for USDA-FSIS to EPA establishes the limits for pesticide conclude that a USDA-FSIS-regulated product residues in foods under the Food Quality contains a pathogen or is otherwise harmful Protection Act (44). EPA is also authorized to to human health, but the investigation has not set standards for drinking water in the Safe identified a product that can be recalled Drinking Water Act (45). 40 Council to Improve Foodborne Outbreak Response
2.4 Legal Framework to Prevent or Mitigate Foodborne Illness Outbreaks
2.4.2 State public health, agriculture, and • Embargoing, seizing, or destroying 2 food and drug agencies each play a role in contaminated food or requiring removal of
mitigating and preventing outbreaks of contaminated lots from retail stores; foodborne illness. Each agency operates • Closing food establishments representing an under one or more specific statutory imminent public health threat; and and regulatory authorities. How these roles and authorities are structured and the • Issuing press releases assignment of responsibilities between the These actions are taken through agency state and its localities vary by state. Local authority granted by statute and implemented health departments in general operate under through rules or through administrative orders. two frameworks: independent home rule and In issuing an administrative order closing delegated authority. a restaurant, for example, such an order State and/or local agencies are authorized to should contain time limits for the closure and LEGAL PREPAREDNESS FOR THE FOR THE LEGAL PREPAREDNESS undertake a range of actions to mitigate and specify the conditions that would permit the prevent outbreaks, including restaurant to reopen. If necessary, agencies OF FOODBORNE ILLNESS OUTBREAK can seek enforcement of their administrative • Requiring changes in food preparation; orders through the court. • Temporarily removing persons with infectious illnesses from the workplace; SURVEILLANCE, INVESTIGATION, AND CONTROL AND CONTROL SURVEILLANCE, INVESTIGATION,
2.5 Evolving Legal Issues
Even though reporting, surveillance, and For other groups, deregulation is the primary mitigation of foodborne disease outbreaks focus of food sovereignty laws. is well established in state and federal law, issues continue to arise that demonstrate For example, Maine enacted a law in October differences in state and federal law. Such 2017 authorizing municipalities to “adopt issues further demonstrate the ongoing need ordinances regarding local food systems and for communication and collaboration among community self-governance that set forth local, state, and federal officials who are provisions that apply exclusively to direct united in the common goal of protecting the producer-to-consumer food exchanges public’s health. and other traditional foodways” (46). The provisions essentially remove state oversight 2.5.1 Food sovereignty initiatives are based from certain food-production areas. The state, on the idea that people should have the however, retains authority to implement and ability to democratically control their enforce rules related to the inspection of meat own food and agriculture policies. For and poultry producers. This version of the some groups, the concept is tied to reducing statute took effect after USDA questioned poverty and providing healthy food through whether the original version of the law would ecologically sound and sustainable metrics. have enabled Maine to maintain its “at least These groups also focus on strategies to resist equal to” status and continue to operate its and dismantle corporate food production and meat and poultry inspection programs. The increase local food production and control. law also requires that anyone who “grows, 2020 | Guidelines for Foodborne Disease Outbreak Response 41
2.5 Evolving Legal Issues produces, processes or prepares food or food foods eligible for sale typically are considered products intended for any wholesale distribution safe from bacterial contamination and do not 2 or retail distribution outside of ” a municipality require time or temperature safety measures to comply with state and federal food-safety for production and/or storage (47). Examples OF FOODBORNE ILLNESS OUTBREAK SURVEILLANCE, INVESTIGATION, AND CONTROL LEGAL PREPAREDNESS FOR THE laws, rules, and regulations (46). include baked goods, candies, condiments, preserves, and dry mixes. Cottage food 2.5.2 While acknowledging the differing laws are viewed as promoting economic positions of the federal government and opportunities for home- and farm-based food many states on the legality of marijuana businesses, while providing some regulatory use for medical and nonmedical purposes, safeguards of these businesses. As of June food-safety concerns exist that are related 2018, 49 states and the District of Columbia to the incorporation of marijuana, hemp have some type of cottage food law; derivatives, and cannabidiol in food New Jersey did not have such a law (48,49). (edibles). States are continuing to work on the application of food-safety laws to the Although cottage food laws vary among states, producers of such edibles. Some states subject these laws generally address the types of foods those who produce edibles to state food worker permitted to be sold, who can sell, limits on restrictions and/or to local and state kitchen- sales, and labeling licensing, permitting and/ related health and safety standards used for or inspection requirements (50). In many states retail food establishments. efforts are ongoing to expand the permitted foods or alter restrictions on sales. Any move 2.5.3 Cottage food laws collectively refer to change existing cottage food laws, either by to state laws and regulations that allow expanding them or adding limitations, should for the sale, with restrictions, of certain be done so with food safety and the public’s foods produced in private homes. The health in mind.
2.6 Public Health Investigations as the Basis for Further Action
The goal of a foodborne illness outbreak and international scope of food production, investigation is to identify and control the the informational and regulatory traceback source of the outbreak. In the course of investigations might involve multiple state the investigation, officials may find issues and federal regulatory agencies. Violations of that require the initiation of regulatory or federal or state law that are identified during administrative actions or even civil or criminal a regulatory traceback investigation may proceedings. lead to further action, such as seizure of the implicated foods or injunctive remedies. 2.6.1 Data collected during a public health investigation can become the basis for Local and state agencies also can initiate further action by the health agency or administrative actions over persons or other state and federal agencies. For businesses that violate state or local regulations. example, if epidemiologic and laboratory data For example, if a restaurant has repeated provide evidence linking illness to consumption food handling or food storage violations, it of a particular food, an informational may be subject to administrative hearings traceback investigation can result to identify leading to suspension or revocation of its the source of that food. Given the national food-service license. 42 Council to Improve Foodborne Outbreak Response
2.6 Public Health Investigations as the Basis for Further Action
2.6.2 If during an investigation it is especially in situations requiring a joint suspected or confirmed that a foodborne investigation. Laboratory specimens collected
2 illness outbreak was caused because of for regulatory purposes must be collected and criminally negligent behavior, intentional submitted using procedures that ensure the contamination or bioterrorism, additional chain-of-custody of the specimen is admissible state criminal, antiterrorism, and in court (51). Chain-of-custody is a process emergency response laws will enhance that may be followed for evidence to be legally or dictate the course of the outbreak defensible and includes the following main investigation and response. If the outbreak elements: properly identifying the evidence, is multistate, then federal response resources a neutral evidence collector, tamper-proofing and laws apply, and local and state public and securing evidence at the collection site, and health agencies must work closely with other keeping physical control of the evidence. state and federal agencies. Local and state officials, in collaboration Joint investigations by public health, food, with law enforcement agencies, should
LEGAL PREPAREDNESS FOR THE FOR THE LEGAL PREPAREDNESS agriculture, and law enforcement agencies periodically assess the need for memoranda can be hindered by the different legal powers of understanding to clarify the roles of public
OF FOODBORNE ILLNESS OUTBREAK and investigatory practices each agency brings health, food, agriculture, and law enforcement to such an event. For example, officials from agencies in conducting joint investigations. public health agencies are authorized to collect Local and state officials who have roles in and test samples to determine their public investigating foodborne illness outbreaks should
SURVEILLANCE, INVESTIGATION, AND CONTROL AND CONTROL SURVEILLANCE, INVESTIGATION, health threat, whereas law enforcement officials understand and demonstrate competence in can consider samples subject to seizure as applying their legal authorities in conducting evidence. Public health, food, agriculture, and joint investigations. Resources for improving law enforcement officials all must conform to competency in joint investigations include constitutional standards (e.g., Fourth and Fifth CDC training curricula (52) and sample Amendments) about collection of evidence, memoranda of understanding (53).
2.7 CIFOR Legal Preparedness Resources
CIFOR has created several resource • Analysis of State Legal Authorities documents to further assist local and state for Foodborne Disease Detection and public health agencies in improving their Outbreak Response. This document legal preparedness to conduct surveillance for describes and analyzes the types of state legal foodborne illness and respond to outbreaks authorities available to conduct foodborne within their jurisdictions and across multiple illness surveillance and outbreak response states and other jurisdictional boundaries. The activities. It highlights the patchwork of state CIFOR Law Project created the following laws and regulations across several topic three documents, each designed to address areas—public health, communicable disease, a discrete, but related, research need and food safety, food regulation, agriculture, audience. All the documents are available environmental health, and general through the CIFOR website: https://cifor.us/ government authority—on which public products/law-project health professionals and their legal counsel must rely to accomplish foodborne illness surveillance and outbreak response activities. 2020 | Guidelines for Foodborne Disease Outbreak Response 43
2.7 CIFOR Legal Preparedness Resources
• Practitioners’ Handbook on Legal • Menu of Legal Options for Foodborne Authorities for Foodborne Disease Disease Detection and Outbreak 2 Detection and Outbreak Response. Response. This document provides a This document is a practical guide for menu of legal options for state public OF FOODBORNE ILLNESS OUTBREAK SURVEILLANCE, INVESTIGATION, AND CONTROL LEGAL PREPAREDNESS FOR THE public health professionals who perform health officials and policy makers to key roles in foodborne illness surveillance consider when reviewing their jurisdiction’s and outbreak response. The handbook legal authorities to conduct foodborne presents information and resources for illness surveillance and outbreak response practitioners charged with implementing actions. The menu includes legal provisions their jurisdiction’s legal authorities related relevant to activities conducted during to foodborne disease events. The handbook foodborne illness surveillance and outbreak is a primer on the array of possible legal response—outbreak detection, outbreak authorities (e.g., communicable disease laws, investigation, outbreak control, and food-safety laws) that might be available and outbreak documentation. It is intended provides practitioners with checklists for to be a resource for states to use in filling
identifying relevant agency actors and laws gaps and clarifying or enhancing their legal within their jurisdictions. authorities. 44 Council to Improve Foodborne Outbreak Response
References
1 Moulton AD, Gottfried RN, Goodman RA, Murphy 17 U.S. Department of Agriculture, Food Safety AM, Rawson RD, What Is public health legal Inspection Service. FSIS Directive 2620.5. Sharing preparedness? J Law Med Ethics. 2003;31 (Supp. information with state or local agencies, foreign 2 4):672–83. http://journals.sagepub.com/doi/10.1111/ government officials, and international organizations
j.1748-720X.2003.tb00134.x (September 25, 2018). https://www.fsis.usda.gov/ 2 Northwest Center for Public Health Practice. Practical wps/wcm/connect/9865dcdf-068c-4e2f-891f-ef93b8 law for public health officials.http://www.nwcphp. 79e831/2620.5.pdf ?MOD=AJPERES org/docs/phlaw/phlaw_print_version.pdf 18 Centers for Disease Control and Prevention. Menu 3 Council to Improve Foodborne Outbreak Response. of suggested provisions for public health mutual aid CIFOR industry guidelines: foodborne illness agreements. https://www.cdc.gov/phlp/publications/ guidelines for owners, operators, and managers of food type/mmou.html establishments. Washington, DC: National Association 19 The Network for Public Health Law. Resource: of County and City Health Officials, 2013. intergovernmental cooperation agreements http://cifor.us/products/industry map. https://www.networkforphl.org/ 4 Jacobson v. Massachusetts, 197 U.S. 11 (1905). resources_collection/2013/12/02/388/resource_ intergovernmental_cooperation_agreements_map 5 Public Health Service Act, as amended. Codified at 42 20 Food and Drug Administration Amendments Act of LEGAL PREPAREDNESS FOR THE FOR THE LEGAL PREPAREDNESS U.S.C. Chapter 6A. 2007. Pub. L. No. 110-85, 1221 Stat. 823 (2007). 6 Association of Public Health Laboratories. State legal
OF FOODBORNE ILLNESS OUTBREAK requirements for submission of isolates and other 21 Food Safety Modernization Act. Pub. L. No. 111–353, clinical materials by clinical laboratories: a review 124 Stat. 3885 (2011). of state approaches (December 2015). https://www. 22 Food and Drug Administration. Current Good aphl.org/aboutAPHL/publications/Documents/ Manufacturing Practice, Hazard Analysis, and StateRequirements_Appendix_v6.pdf Risk-Based Preventive Controls for Human Food. SURVEILLANCE, INVESTIGATION, AND CONTROL AND CONTROL SURVEILLANCE, INVESTIGATION, 7 Health Insurance Portability and Accountability Act 21 CFR 117. of 1996. Pub. L. No. 104-191, 110 Stat. 1936 (1996). 23 Food and Drug Administration. FSMA Final Rule Codified at 42 U.S.C. § 300gg and 29 U.S.C § 1181 et for Preventive Controls for Human Food. https:// seq. and 42 USC 1320d et seq. www.fda.gov/Food/GuidanceRegulation/FSMA/ 8 HIPAA Privacy Rule. 45 CFR Part 160 and Subparts A ucm334115.htm and E of Part 164. 24 Food and Drug Administration. Current Good 9 45 C.F.R. § 160.103. Manufacturing Practice, Hazard Analysis, and Risk-Based Preventive Controls for Food for Animals. 10 45 C.F.R. §§ 164.502(d)(2), 164.514(a). 21 CFR 507. 11 Privacy Act of 1974, as amended. Codified at 5 25 Food and Drug Administration. FSMA Final Rule U.S.C. § 552a.7. for Preventive Controls for Animal Food. https:// 12 21 C.F.R. 20.88. www.fda.gov/Food/GuidanceRegulation/FSMA/ ucm366510.htm 13 US Department of Health and Human Services. Information sharing. https://www. 26 FDA Foreign Supplier Verification Programs for fda.gov/ForFederalStateandLocalOfficials/ Importers of Food for Humans and Animals. CommunicationsOutreach/ucm472936.htm 21 CFR 1. 14 21 U.S.C. § 372(a). 27 Food and Drug Administration. FSMA Final Rule on Foreign Supplier Verification Programs (FSVP) for 15 US Department of Health and Human Importers of Food for Humans and Animals. https:// Services. Commissioning. https://www. www.fda.gov/Food/GuidanceRegulation/FSMA/ fda.gov/ForFederalStateandLocalOfficials/ ucm361902.htm CommunicationsOutreach/ucm472941.htm 28 Food and Drug Administration. Mitigation Strategies 16 Federal Food, Drug, and Cosmetic Act, as amended. to Protect Food Against Intentional Adulteration. Codified at 21 U.S. Code Chapter 9. 21 C.F.R. 121. 2020 | Guidelines for Foodborne Disease Outbreak Response 45
References
29 Food and Drug Administration. FSMA Final Rule 44 Food Quality Protection Act of 1996. Pub. L. No.104- for Mitigation Strategies to Protect Food Against 170, 110 Stat. 1489 (1996). Codified in various Intentional Adulteration. https://www.fda.gov/Food/ sections at 7 U.S.C. Chapter 6. 2 GuidanceRegulation/FSMA/ucm378628.htm 45 Safe Drinking Water Act. Pub. L. No. 93-523, 88 Stat. OF FOODBORNE ILLNESS OUTBREAK SURVEILLANCE, INVESTIGATION, AND CONTROL LEGAL PREPAREDNESS FOR THE 30 Food and Drug Administration. Sanitary 1660 (1974), as amended. Codified at 42 U.S.C. 300f Transportation of Human and Animal Food. et seq. 21 CFR 1. 46 7 M.R.S. §281 et seq. (2017). 31 FDA. FSMA Final Rule on Sanitary Transportation 47 Food and Drug Administration. Food Code of Human and Animal Food. https://www.fda.gov/ 1-201.10(B) (2017). Food/GuidanceRegulation/FSMA/ucm383763.htm 48 U.S. Department of Agriculture. National 32 Food and Drug Administration. Standards for the Agricultural Library. Agricultural Law Information Growing, Harvesting, Packing, and Holding of Partnership: Local Foods. https://www.nal.usda.gov/ Produce for Human Consumption. 21 CFR 112. aglaw/local-foods#quicktabs-aglaw_pathfinder=3 33 Food and Drug Administration. FSMA Final Rule 49 Harvard Food Law and Policy Clinic. Cottage food on Produce Safety. https://www.fda.gov/Food/ laws in the United States (August 2013). https://www. GuidanceRegulation/FSMA/ucm334114.htm chlpi.org/wp-content/uploads/2013/12/FINAL_
34 Food and Drug Administration. Accreditation of Cottage-Food-Laws-Report_2013.pdf Third-Party Certification Bodies to Conduct Food 50 Adams E, Hall PK. Cottage food laws: adequately Safety Audits and to Issue Certifications. 21 CFR 1. addressing food safety and economic opportunity? 35 Food and Drug Administration. FSMA Final Rule Presentation for National Agricultural Law Center on Accredited Third-Party Certification. https:// (June 20, 2018). http://nationalaglawcenter.org/ www.fda.gov/Food/GuidanceRegulation/FSMA/ wp-content/uploads/2018/04/Cottage-Foods-for- ucm361903.htm NALC-2018.pdf 36 Food and Drug Administration. Voluntary Qualified 51 Lazzarini Z, Goodman RA, Dammers KS. Criminal Importer Program (VQIP). https://www.fda.gov/ law and public health practice. In: Goodman RA, Food/GuidanceRegulation/ImportsExports/ Hoffman RE, Lopez W, Matthews GW, Rothstein Importing/ucm490823.htm MA, Foster KL, editors. Law in Public Health 37 Food and Drug Administration. FDA Food Code. Practice. 2nd ed. New York: Oxford University Press; https://www.fda.gov/food/guidanceregulation/ 2007:136–67. retailfoodprotection/foodcode/default.htm 52 Centers for Disease Control and Prevention. 38 Federal Meat Inspection Act of 1906. Pub. L. No. Forensic epidemiology training curricula 59-242, 34 Stat. 1256 (1907), as amended. Codified at (version 3.0). https://www.cdc.gov/phlp/ 21 U.S.C. 601 et seq. publications/forensicepidemiology/index.html 39 Poultry Products Inspection Act of 1957. Pub. L. No. 53 Centers for Disease Control and Prevention. Model 85-172, 71 Stat. 441 (1957), as amended. Codified at memoranda of understanding. https://www.cdc.gov/ 21 U.S.C. 451 et seq. phlp/publications/type/mmou.html 40 Egg Products Inspection Act. Pub. L. No. 91-597, 84 Stat. 1620 (1970). Codified at 21 U.S.C. 1031 et seq. 41 U.S. Department of Agriculture. Food Safety Inspection Service. FSIS Directive 8080.3 Rev. 2 “Foodborne Illness Investigations” (October 27, 2017). https://www.fsis.usda.gov/wps/wcm/ connect/1bffb125-cd80-4b3a-ab45-1f4c0ad863d9/80 80.3.pdf ?MOD=AJPERES 42 Animal Health Protection Act. Pub. L. No. 107-171, 116 Stat. 494 (2002). Codified at 7 U.S.C. 8301 et seq. 43 Plant Protection Act. Pub. L. No. 106–224, 114 Stat. 438 (2000). Codified at 7 U.S.C. 7701 et seq.
CHAPTER 3
Planning and Preparation: Building Teams
CHAPTER SUMMARY POINTS
• This chapter describes the roles of the core outbreak investigation and control
team members and major agencies and partners involved in foodborne illness
outbreak response and highlights the resources, processes, and relationships
that should be in place before an outbreak.
• Agency plans, training programs, and response partner working relationships
must anticipate the need to rapidly expand and contract the scope and structure
of investigation and control teams to address changing conditions.
• Key roles in outbreak detection and response include epidemiology,
environmental health and public health, and laboratory practice.
• A core team should be involved in all outbreak investigation and control efforts,
giving consistency to investigations, serving as the focal point for coordinating
multidisciplinary and/or multiagency tasks, and enabling development of
effective working relationships with external partners and advanced expertise
among staff.
URLs in this chapter are valid as of August 7, 2019. 48 Council to Improve Foodborne Outbreak Response
3.0 Introduction
3.0.1 This chapter describes the roles and contract the scope and structure of of the core outbreak investigation and investigation and control teams to address control team members, major agencies, changing conditions. All agencies should and partners involved in foodborne illness maintain standard procedures and all-hazards outbreak response and highlights the emergency operations plans identifying the resources, processes, and relationships mechanisms for conducting routine and that should be in place before an outbreak. nonroutine investigations and responses. This 3
Agencies must be prepared to mount and chapter promotes practices that have been participate in effective single-agency and helpful in developing effective multidisciplinary multiagency responses to incidents ranging foodborne illness investigation and control from local to potentially national in scope. teams and provides links to related topics. The authority to identify, investigate, and These Guidelines contain detailed information control foodborne illness outbreaks is shared about outbreak investigation and response. All across local, state, territorial, tribal, and federal responsible agencies should regularly work with BUILDING TEAMS government agencies. Each agency at every their attorneys to anticipate legal issues that level of government has specific roles and can arise during foodborne illness outbreak responsibilities. investigation and control. (See Chapter 2 for details about legal preparedness and the 3.0.2 Agency plans, training programs, and CIFOR law project that provides additional
PLANNING AND PREPARATION: PLANNING AND PREPARATION: response partner working relationships tools to help agencies and jurisdictions improve must anticipate the need to rapidly expand legal preparedness.)
3.1 Roles
3.1.1 Key roles in outbreak detection 3.1.2 Agencies’ roles, responsibilities, and and response include epidemiology, resources influence outbreak responses. environmental health, and laboratory. The nature of the outbreak, including the These roles are distributed across the multiple type of pathogen or contaminant, severity of entities—more than 3,000 local health illness, suspected or implicated vehicle, number departments, more than 50 state and territorial and location of affected persons, geographic health departments, other state agencies, tribal jurisdictions involved, and local and state food organizations, and several federal agencies— safety rules and laws (Chapter 2) determine that interact in a complex system to detect the individuals, disciplines (further discussed in and respond to enteric and other human and section 3.2), and types of agencies that need to animal foodborne illnesses. These roles include be involved. (Table 7.3 in Chapter 7 provides conducting surveillance to detect outbreaks detailed information about multijurisdictional through complaint-based, pathogen-specific, outbreak identification methods and required or other forms of surveillance (Chapter 4) notification steps, by agency level). and rapidly conducting outbreak investigation activities to identify the mode of transmission Each agency’s response plan should include and vehicle (Chapter 5) and determine the its likely role in a foodborne illness outbreak potential for ongoing transmission and need investigation, staff (or positions) that may be for control procedures (Table 5.1 in Chapter 5; involved, contact information for relevant Chapter 6). external agencies, and communication and escalation procedures for working with those agencies. 2020 | Guidelines for Foodborne Disease Outbreak Response 49
3.1 Roles
3.1.3 Local and state (Table 3.1) and national park should establish relationships federal (Table 3.2) levels, other important with the National Park Service Office of Public cross-agency programs (Table 3.3), Health. On many other types of federal lands, and nongovernment, industry and state laws apply, but federal agencies may have academic partners (Table 3.4) contribute overlapping responsibilities. The Department to foodborne illness investigation and of Defense has autonomous authority over outbreak response. For local and state U.S. military bases, facilities (including food 3
agencies, responsibilities vary depending on production, food service, and healthcare BUILDING TEAMS PLANNING AND PREPARATION: a state’s organizational, legal, and regulatory facilities), and vehicles. structure; the distribution of responsibilities across different types of local and state Indigenous tribes have complete sovereignty agencies; and the size and capacity of the and are completely autonomous. Investigations local agencies. Responsibilities for federal on tribal land may be conducted by tribal agencies follow regulatory jurisdictions for health staff, Indian Health Service staff, Food and Drug Administration (FDA) and the or state or local health agencies, but U.S. Department of Agriculture’s (USDA’s) nontribal entities can become involved in Food Safety Inspection Service (FSIS), and an investigation only at the tribe’s request. public health surveillance and disease control Memoranda of understanding may establish mandates for the Centers for Disease Control lines of communication and reciprocal support during public health emergencies. and Prevention (CDC).
In addition to these primary federal agencies, Law enforcement agencies at multiple levels several other federal jurisdictions may be will become involved in an investigation if relevant to outbreak investigations. The intentional contamination of food or other National Park Service may have exclusive criminal activity is suspected. Agencies or shared jurisdiction with state and local responsible for controlling foodborne illness agencies depending on legislation designating outbreaks should establish relationships the specific park. Local and state agencies and communication pathways with law whose jurisdiction contains or adjoins a enforcement agencies before any outbreak.
Table 3.1. Examples of Typical Foodborne Outbreak Investigation Roles, Responsibilities, and Contributions of Local and State Agencies* AGENCY ROLES, RESPONSIBILITIES, AND CONTRIBUTIONS Local health Responsible for local policies to protect public health: agencies • Maintain communication and working networks with local populations and community and businesses, healthcare providers and community organizations, and other local resources. laboratories • Regulate and inspect food service establishments and educate food workers about food safety. • Conduct complaint-based, pathogen-specific, and other forms of surveillance to identify local outbreaks. • Investigate and control potential foodborne illnesses using local authorities, policies, and resources. • Manage local public risk communication during foodborne outbreaks. • Coordinate investigation and communication activities with other agencies and response partners during multijurisdictional outbreaks. • Conduct after-action reviews to improve investigation effectiveness and prevent future outbreaks from the same causes. 50 Council to Improve Foodborne Outbreak Response
3.1 Roles
Table 3.1. Examples of Typical Foodborne Outbreak Investigation Roles, Continued Responsibilities, and Contributions of Local and State Agencies* AGENCY ROLES, RESPONSIBILITIES, AND CONTRIBUTIONS State health Responsible for statewide public health protection: department • Conduct statewide pathogen-specific surveillance; some states may also coordinate and statewide complaint-based surveillance. 3 laboratories • Provide technical assistance and surge capacity for local and state response partner agencies as needed; conduct investigations in local areas without local health agency jurisdiction. • Conduct and coordinate statewide or multijurisdictional investigations of outbreaks of human illness, including foodborne illness outbreaks. • Manage statewide public risk communication during foodborne illness outbreaks. • Serve as liaison with nongovernment response partners and stakeholders, including healthcare providers and food industry representatives.
BUILDING TEAMS • Provide legal support for outbreak investigation and control activities. • Conduct after-action reviews to improve investigation effectiveness and prevent future outbreaks from the same causes. State food Responsible for statewide policies to protect food safety: safety • Conduct routine regulatory inspections and activities for food establishments under their regulatory jurisdiction. PLANNING AND PREPARATION: PLANNING AND PREPARATION: authorities • Maintain 1) knowledge of food industry practices in their jurisdiction and 2) working and relationships with food industry managers, associations, and technical experts. laboratories† • Conduct investigations of food producers, food establishments, and food supply chains within their jurisdiction, including product tracing investigations (traceback, traceforward), environmental health assessments, sampling, and implementation of regulatory control measures. • Provide technical assistance and surge capacity for local and state response partner agencies as needed. • Coordinate response actions with local, state, and national food supply stakeholders and response partners, including law enforcement for instances of suspected intentional contamination. • Conduct after-action reviews to improve investigation effectiveness and prevent future outbreaks from the same causes. *The three core disciplines involved in foodborne outbreaks—epidemiology, environmental health/food regulatory program, and laboratory—may be housed in the same agency at the state or local level. †Agencies with different names (e.g., Department of Agriculture, Health, or Environmental Health) may carry out these roles. 2020 | Guidelines for Foodborne Disease Outbreak Response 51
3.1 Roles
Table 3.2. Examples of Typical Foodborne Illness Outbreak Investigation Roles, Responsibilities, and Contributions of Primary Federal Agencies AGENCY ROLES, RESPONSIBILITIES, AND CONTRIBUTIONS U.S. Food Responsible for investigation and regulation of most foods moving in interstate and Drug commerce (except products regulated by the U.S. Department of Agriculture’s Food
Administration Safety and Inspection Service [USDA-FSIS]) (Appendix) 3 (FDA, DHHS) • Perform regulatory activities, including facility registration, routine risk-based BUILDING TEAMS PLANNING AND PREPARATION: inspections, limited food supply surveillance testing, and compliance and enforcement. • Publish voluntary regulatory food safety standards for food service and retail food establishments (the model FDA Food Code) (1). • Coordinate and collaborate with international food regulatory agencies, and support capacity building and training in product-related aspects of investigation and laboratory methods pertaining to foods that FDA regulates. • Conduct outbreak investigations: The Coordinated Outbreak Response and Evaluation network (CORE) (2) for investigations of human illness potentially linked to human food, the National Shellfish Sanitation Program (NSSP) for human illness potentially linked to shellfish products, the Center for Veterinary Medicine for human illness potentially linked to animal food or feed, and the Office of Emergency Operations.
• Coordinate with states on informational product tracing for use as part of exposure assessments in epidemiologic studies potentially linked to FDA-regulated products. • Conduct investigations and environmental health assessments of food establishments under their jurisdiction in coordination with other government partner agencies. • Conduct laboratory testing of product(s) obtained from commerce, consumer homes, or production. • Coordinate communication with states and with other federal agencies, particularly CDC, during foodborne outbreak investigations. • mplement short- and long-term control measures and follow-up activities as needed to protect public health consistent with regulatory authorities. • Conduct after-action reviews. 52 Council to Improve Foodborne Outbreak Response
3.1 Roles
Table 3.2. Examples of Typical Foodborne Illness Outbreak Investigation Roles, Continued Responsibilities, and Contributions of Primary Federal Agencies AGENCY ROLES, RESPONSIBILITIES, AND CONTRIBUTIONS FSIS, USDA Responsible for ensuring that meat, poultry, and processed egg products are safe, wholesome, and accurately labeled: • Perform inspection and regulatory activities to ensure industry compliance with 3 applicable laws, pathogen reduction and hazard analysis and critical control point
system regulations and other regulations, robust food supply surveillance testing, and compliance and enforcement. • Perform scientific and technical assessments of known and emergent hazards, including quantitative microbial risk assessments. • Conduct outbreak investigations: In-plant inspectors at FSIS-regulated establishments with operational knowledge of industry food safety systems (Office of Field Operations); in-commerce compliance investigators with expertise BUILDING TEAMS in sample collection and informational traceback (Office of Investigation, Enforcement, and Audit); and public health science personnel with expertise in performing epidemiologic and environmental assessments (Office of Public Health Science). • Perform informational traceback for use as part of exposure assessments in epidemiologic studies potentially linked to FSIS-regulated products, coordinating PLANNING AND PREPARATION: PLANNING AND PREPARATION: with states, where possible. • Conduct investigations and environmental assessments of FSIS-regulated establishments and in-commerce facilities in coordination with other government partner agencies. • Conduct laboratory testing of product(s) collected from FSIS-regulated establishments, in-commerce facilities, and consumer homes. • Assess testing results from non-FSIS laboratories to determine whether they can be used to support FSIS outbreak response. • Coordinate communication and exchange information with states and other federal agencies, particularly CDC, during foodborne outbreak investigations. • Implement short- and long-term control measures and follow up activities as needed to protect public health consistent with regulatory authorities. • Conduct after-action reviews. 2020 | Guidelines for Foodborne Disease Outbreak Response 53
3.1 Roles
Table 3.2. Examples of Typical Foodborne Illness Outbreak Investigation Roles, Continued Responsibilities, and Contributions of Primary Federal Agencies AGENCY ROLES, RESPONSIBILITIES, AND CONTRIBUTIONS CDC, DHHS Responsible for conducting or coordinating surveillance for human illnesses caused by pathogens commonly transmitted through food and for outbreaks of foodborne illnesses of any cause: 3 • Lead and support national surveillance, communication and disease investigation BUILDING TEAMS PLANNING AND PREPARATION: networks, including National Notifiable Disease Surveillance System (NNDSS), Foodborne Diseases Active Surveillance Network (FoodNet), The National Molecular Subtyping Network for Foodborne Disease Surveillance (PulseNet), NEARS National Environmental Assessment Reporting System, Foodborne Disease Outbreak Surveillance System (FDOSS), National Outbreak Reporting System (NORS), Foodborne Disease Centers for Outbreak Response Enhancement (FoodCORE), OutbreakNet Enhanced (OBNE), the Integrated Food Safety Centers of Excellence (COE), Norovirus Laboratory Surveillance Network (CaliciNet), and Norovirus Sentinel Testing and Tracking (NoroSTAT). • Develop and implement better tools for collecting and analyzing public health surveillance and outbreak-associated information. • Improve and standardize laboratory testing methods of clinical specimens for foodborne illness pathogens, including resources to develop new testing methods.
• Provide training in epidemiologic and environmental health investigation and laboratory methods related to human enteric disease surveillance as mandated by the Food Safety Modernization Act (3) through the Centers of Excellence and under other longstanding CDC roles. • Conduct outbreak investigations: Provide clinical, epidemiologic, and laboratory expertise in pathogens of public health importance; epidemiologic and environmental health expertise to assist with cluster evaluation and outbreak investigations; expertise in water systems and large-volume water sample collection. Provide leadership, coordination, logistical support, surge capacity, and centralized data collection and analysis for multistate outbreaks. Coordinate communication with collaborating state and local agencies, other federal agencies, and international partners. Provide advanced laboratory testing of clinical specimens (and occasionally consumer-held food products), including identification of new or rare disease agents. • Lead after-action review of human health investigation component of multistate outbreak investigations. 54 Council to Improve Foodborne Outbreak Response
3.1 Roles
Table 3.3. Examples of Typical Foodborne Outbreak Investigation Roles, Responsibilities, and Contributions of Cross-Agency Programs PROGRAM ROLES, RESPONSIBILITIES, RESOURCES, AND CONTRIBUTION Rapid Response Responsible for implementing partnership between the Food and Drug Administration Teams (RRT) (FDA) and state programs to build food safety infrastructure and integrated rapid response for all-hazards human and animal food emergencies: 3 • Maintain and promote RRT Best Practices Manual (4)
Food outbreak and all-hazard human and animal food emergency response procedures, specific disease agents, epidemiologic and environmental outbreak investigation, informational traceback and implicated product traceforward. Collection of environmental and food samples for chemical, radiologic, physical, and microbial contaminant analysis. • Provide training in outbreak response methods for local health agencies. • Conduct outbreak investigations. The RRT serves as the Outbreak Investigation and BUILDING TEAMS Control Team for multijurisdictional and state-level outbreaks: Lead, assist, and support investigations conducting facility inspections; informational traceback investigations; and food recalls that involve food products (manufactured, commercially produced, and retail) through consultation with health department investigators, federal food safety agency partners, and food industry firms. PLANNING AND PREPARATION: PLANNING AND PREPARATION: Initiate chain-of-custody, quality assurance, and safety procedures when collecting and submitting food samples to support regulatory response. Food Emergency Responsible for prevention, preparedness, response, and recovery activities (5): Response • Maintain an integrated network of local, state, and federal laboratories across the Network United States that are capable of rapid response to food-related emergencies and attacks on the U.S. food supply. • Detect and identify biological, chemical, and radiologic agents in food, and provide food testing surge capacity during national emergencies.
Table 3.4. Examples of Typical Foodborne Outbreak Investigation Roles, Responsibilities, and Contributions of Nongovernment, Industry, and Academic Partners PARTNER ROLES, RESPONSIBILITIES, AND CONTRIBUTIONS Healthcare Responsible for appropriate testing, provision of patient care, and reporting of required Providers illnesses and conditions: • Maintain supplies (specimen collection kits) and trained staff to support outbreak investigations. • Speed detection, investigation, and control of foodborne illness outbreaks by Gathering of preliminary exposure and clinical history. Early recognition and reporting of possible outbreaks. Timely collection and submission of appropriate specimens for testing. Application of infection control measures. • Provide appropriate patient education and information to prevent further spread of disease. 2020 | Guidelines for Foodborne Disease Outbreak Response 55
3.1 Roles
Table 3.4. Examples of Typical Foodborne Outbreak Investigation Roles, Responsibilities, Continued and Contributions of Nongovernment, Industry, and Academic Partners PARTNER ROLES, RESPONSIBILITIES, AND CONTRIBUTIONS Industry* Responsible for maintaining the safety of food offered to the public: • Firm Level: A specific point of sale, distributor, manufacturer, processor, or farm that is
directly impacted by an ongoing outbreak investigation. 3 Have detailed knowledge about the firm’s processes and organizational culture that are key to understanding possible BUILDING TEAMS PLANNING AND PREPARATION: . Point(s) of contamination. . Contributing factors. . Underlying environmental root cause(s) (i.e., antecedent[s], underlying reason[s]) that lead to outbreaks. Communicate with employees, suppliers, government agencies, and customers during outbreaks. Implement control measures that can stop the current outbreak and prevent reoccurrence. . Firm level controls, e.g., employee restrictions/exclusion, food process changes. . In-distribution controls: cease distribution and initiate recalls See CIFOR Industry Guidelines for further details relevant to the food service
and retail food sectors (https://cifor.us/products/industry). • Commodity-Specific and Regional Levels: Groups and associations focused on a specific commodity or product Can provide expertise on how the commodities or products are grown, processed, manufactured, packed, distributed, and served. Discussions with this level of industry can help investigators better understand how to investigate contamination issues. Have preexisting networks that can be used to . Gather and provide information needed during the investigation. . Communicate the findings of outbreak investigations to relevant individuals and entities. . Build consensus regarding changes needed to protect public health and consumer confidence in their products. • National Level: Groups and associations that represent many food-related entities at the national level: Can provide expertise on how a range of food products are grown, processed, manufactured, packed, distributed, and served. Ongoing collaboration and partnership with these groups is important for changes to laws, regulations, policies, and initiatives that impact industries nationally. Academic Responsible for providing technical assistance, training, and specialized laboratory centers support: • Publish research results to help inform future outbreak investigations and implement control measures (e.g., NoroCORE) (6). • Conduct special laboratory analyses or provide additional resources. • Conduct applied food safety research to expand results of investigations. * Partnerships with individuals and entities at each level should be well-established, and discussions should be ongoing, not occur just during an outbreak crisis. 56 Council to Improve Foodborne Outbreak Response
3.2 Outbreak Investigation and Control Team
The responsibility for investigating foodborne agencies with limited outbreaks, this might be illness outbreaks and implementing control accomplished by designating a few people who measures rests on a team of people who receive outbreak response training. In large each contribute different knowledge and agencies responding to more frequent and/or skills. Depending on the size and scope of complex outbreaks, this might be a dedicated the investigation, the size of the team varies outbreak response team of epidemiologists, from a few people to hundreds. In smaller environmental health specialist, environmental 3
investigations, individuals may fulfill multiple scientists, and laboratorians who train and roles concurrently. Regardless of the size or work together. complexity of an individual investigation, investigation and control teams must be able • Team leader: Sets and enforces priorities; to synthesize information from a variety of coordinates all activities associated with the sources as they investigate individual cases, investigation; serves as the point of contact clusters, and outbreaks. about the investigation; coordinates content
BUILDING TEAMS of messages to the public through the Job titles alone might not accurately indicate public information officer; communicates who does what. Team members’ assigned with other organizations involved in the tasks and their knowledge and skills define investigation; communicates recommended their roles. Members may come from course of action determined by team to
PLANNING AND PREPARATION: PLANNING AND PREPARATION: different programs within an agency or agency decision-makers. from different agencies. Composition of the outbreak investigation and control team varies • Epidemiologist: Identifies and interviews depending on the specifics of the outbreak. case-patients; develops hypotheses and In many investigations, roles are defined strategies to test them; plans epidemiologic relatively informally and may change as the studies; re-interviews case-patients and investigation unfolds. In other investigations, healthy controls; provides insights and roles are mapped to the formal structure of the guidance to environmental health specialists National Incident Management System, which (and federal regulatory partners) on cases government agencies and Rapid Response and clusters for informational traceback, Teams use (see Section 7.2.3 for specifics collects and analyzes investigation data using about the National Incident Management statistical analyses or collaborating with a System and Incident Command System statistician; reports results; collects clinical [ICS]) (7). The composition of core outbreak specimens; coordinates testing of clinical investigation and control team should be specimens and environmental samples; determined before any outbreaks. consults and coordinates with environmental and laboratory investigators. 3.2.1 A core team should be involved in all outbreak investigation and control efforts, • Environmental health specialist: Investigates giving consistency to investigations, food preparation sites across the food serving as the focal point for coordinating chain; reviews food inventory and food multidisciplinary and/or multiagency distribution records for informational tasks, and enabling development of traceback investigations in epidemiologic effective working relationships with studies; collects environmental and food external partners and advanced expertise samples, maintaining chain-of-custody among staff. The approach for structuring and coordinates testing with laboratorian; an investigation and control team will not interviews food workers and managers; look the same for all agencies. In small reviews food preparation and food 2020 | Guidelines for Foodborne Disease Outbreak Response 57
3.2 Outbreak Investigation and Control Team
handling records; observes and maps They should understand the roles of the other food flow, reviews firm’s inspectional and team members, be able to recognize when an enforcement records for prior food safety outbreak response exceeds agency resources, history; conducts environmental health and know how to expand the investigation assessments to determine contributing team and request additional resources when factors and environmental root causes (i.e., needed. Training and procedures should antecedent[s], underlying reason[s]). anticipate and address how response team 3
members will manage increased coordination BUILDING TEAMS PLANNING AND PREPARATION: • Laboratorian: Analyzes clinical specimens, and communication workloads when outbreak food and environmental samples (depending investigations rapidly escalate. Ongoing on the state, the food and environmental training is critical for all members of the samples may be tested in different outbreak investigation and control team to laboratories than the clinical specimens); ensure they are proficient at performing their interprets test results and suggests follow-up assigned duties. testing; reports results; coordinates testing among laboratories; advises other team At a minimum, the outbreak investigation and members about sampling requirements control team should have training in specific and testing, including collection, handling, protocols for routinely assigned tasks. The storage, and transport of specimens; training should include continuing education
communicates laboratory testing methods to maintain and improve skills within their and results and the maintenance of chain- specialty and specific training in the agency’s of-custody to FSIS and FDA investigators outbreak response protocols and the member’s or other food regulatory agency gathering role on the team. evidence of food product adulteration. For a smaller agency with a limited number • Public information officer:Develops general of outbreak investigations, special training and specific messages for the public through opportunities should be arranged. Consider the media; responds to media inquiries or the use of webinar technology where little or identifies the appropriate spokesperson; no opportunity exists for travel. The CDC- coordinates communication with multiple supported Integrated Food Safety Centers of agencies; disseminates information about Excellence have approximately 150 tools and outbreak status and overall policies, goals, training courses available online at no charge and objectives to widespread and diverse (CoEFoodSafetyTools.org). audiences that include the executive and legislative branches of the government; local • Ensure all team members have a common governments; the general public; and the understanding of the primary goal for local, state, and national news media. outbreak response, which is to implement control measures as quickly as possible to Additional team members with other expertise prevent additional illness. may be needed, depending on the unique • Provide team members with continuing characteristics of the illness or outbreak. education and training opportunities, 3.2.2 Team members should have including cross-training/joint training. the expertise and training needed to • Conduct regional training with multiple competently fulfill assigned responsibilities agencies, including tabletop exercises. Such and tasks for the types of outbreaks they training can help identify problems that might will be expected to investigate and control. arise during a multijurisdictional outbreak. 58 Council to Improve Foodborne Outbreak Response
3.2 Outbreak Investigation and Control Team
• Offer just-in-time training to refresh the and develop communication strategies knowledge and skills of staff who do not that can help streamline actual outbreak routinely perform assigned tasks. investigations. • Identify opportunities to collaborate with • Use outbreak investigations as training representatives of the food industry in opportunities to develop individual and training exercises, to foster understanding organizational skills. 3
3.3 Planning to Rapidly Expand and Contract Investigation and Control Team Structure
Agency plans must anticipate the need to university students, volunteers (e.g., rapidly expand and contract the size and Medical Reserve Corps)—who have BUILDING TEAMS structure of investigation and control teams adequate skills or knowledge and would to address changing conditions, including to be willing to help conduct interviews or participate in multiagency investigation and provide other support during a large-scale control teams (Chapter 7). outbreak. Establish Memorandums of PLANNING AND PREPARATION: PLANNING AND PREPARATION: 3.3.1 The following practices can be used to scale up (escalate) and down (de-escalate) Understanding, Mutual Aid, or other investigation and control teams to meet agreements along with plans, procedures, the often rapidly changing needs of an communication strategies, and protocols outbreak response. before a foodborne illness outbreak. • Ensure foodborne outbreak investigation Consider using ICS principles and team plans and procedures are updated organizational structures, as appropriate, regularly. to manage outbreak responses—especially those that cannot effectively be managed • Determine jurisdiction; investigations may using the agency’s standard operating require management in multiple jurisdictions. procedures and chain of command. • Identify criteria (triggers) used to indicate when the needs of investigation and control 3.3.2 Agencies involved in foodborne teams exceed agency resources, such as illness outbreak investigation and response should decide in advance Size of the outbreak. whether and how to apply an ICS and, if Likelihood that resources will be exceeded. applicable, incorporate the ICS into their response planning. Such planning should be New or rapidly emerging incident. coordinated with all other agencies that may Long duration of incident. be drawn into the investigation and response • Identify resources that can be tapped for over time. Many foodborne illness outbreak surge, and develop relationships and plans investigations do not require formal activation to facilitate quick access to these resources of ICS, but outbreak investigation and control should the need arise. For example: teams will benefit from training in ICS principles and methods (Chapter 7). Cross-train persons from within the agency or from other organizations— such as other branches of government, 2020 | Guidelines for Foodborne Disease Outbreak Response 59
3.4 Response Resources
A critical aspect of preparing to investigate and financial staff to release funds, track a foodborne illness outbreak is assembling expenditures, and assist in procurement of the necessary resources; supplies, equipment, supplies and equipment. people, and outbreak investigation–related • Legal counsel documents (some accessible via reference materials or pertinent databases) to ensure 3.4.2 Develop field investigation or that everything needed in the investigation “go” kits for environmental health 3
and response is quickly available. This enables investigators, including sampling utensils, BUILDING TEAMS PLANNING AND PREPARATION: the outbreak investigation and control team to thermometers, fecal collection kits, move rapidly into the field. and appropriate forms (Box 3.1.). Ensure that relevant field investigators have access 3.4.1 Identify staff to support the Outbreak to these kits and are aware of where they Investigation Team. are located and that the kits are available • Administrative staff: Support personnel to at all times. Foodborne illness outbreak make phone calls, answer incoming calls investigation kits should be maintained in from concerned members of the public, ready-to-use condition, with sterile sampling assist in travel arrangements and other supplies, containers and implements. logistics, enter data into a database, copy Establish, maintain, and review or verify paperwork, and other administrative work. inventory regularly. (Detailed information • Executive and financial staff: Executive staff about kits and sample lists are included at the to guide response priorities and objectives, CIFOR Clearinghouse, https://www.cifor. facilitate communication and role changes, us/clearinghouse and in the International
Box 3.1. Example Supplies for Outbreak Field Investigation Go-Kits • Personal protective equipment to ensure safety and aseptic sampling techniques. • Sterile and wrapped sample-collection supplies (e.g., gloves, spoons, scoops, tongue- depressor blades, spatulas, spongesticks, swabs, knives). • Sterile sample containers (e.g., plastic bags, wide-mouth plastic and glass jars with screw caps, bottles, sterile sampling bags) and mailing instructions. • Sterile fecal sample kits for food workers or case-patients. • Sterilizing and sanitizing agents (e.g., 95% ethyl alcohol, sodium or calcium hypochlorite, alcohol swabs), hand sanitizers, and sanitizer test strips. • Equipment to determine food characteristics (e.g., pH, water activity, sugar content). • Temperature-checking probes and backups. • Refrigerants (e.g., ice packs), insulated containers. • Labeling and sealing equipment (e.g., fine-point or felt-tip permanent marking pen, roll of adhesive or masking tape, waterproof labels or tags, custody tape). • Shipping boxes/coolers, prepaid shipping labels, and forms. • Forms, including sample collection and blank laboratory submission forms, chain-of-custody and other forms for documenting activities. • Camera or other method to visually document the investigation. • Trash bags for the waste generated during the investigation (always take your trash with you). 60 Council to Improve Foodborne Outbreak Response
3.4 Response Resources
Association for Food Protection Procedures These and other sample documents are to Investigate Foodborne Illness (http://www. available from the CIFOR Clearinghouse at foodprotection.org/publications/other- https://cifor.us/clearinghouse. publications/). Procedures for routinely reviewing and replacing missing or outdated 3.4.4 Team members must have access supplies and equipment should be part of an and are trained (if applicable) to use key agency’s outbreak response protocol. databases, communication platforms, 3 and other resources before an outbreak. In addition to the sampling supplies, Although not exhaustive, the following ensure that staff have access to cellular databases, listservs, and other systems are telephones, two-way radios and other team recommended: communication devices appropriate to the • CDC Foodborne Outbreak listserv. response situation, including • PulseNet SharePoint website. • Capabilities and equipment for BUILDING TEAMS conference calls. • System for Enteric Disease Response, Investigation, and Coordination (SEDRIC). • Multiple phone lines. • NCBI Pipeline. • Computers, laptops, software (e.g., data entry, statistical), extension cords, 3.4.5 Assemble a reference library
PLANNING AND PREPARATION: PLANNING AND PREPARATION: multioutlet power strip surge protector, (including online resources) with portable printers, paper, graph paper, pens, information about foodborne illnesses, clipboards, camera. enteric illnesses, and control measures. Where possible, include electronic resources 3.4.3 Make sure investigation and control that can be accessed by laptop computers or team members have access to necessary mobile devices during field investigations. documents and forms and be trained to Regularly review and update the contents of use them appropriately in a response this reference library. situation. These include • Books, Web resources for support during • Chain-of-custody forms. outbreak (e.g., CDC’s Diseases and • Foodborne illness complaint worksheets. Conditions A–Z index, FDA’s Bad Bug Book). • Blank disease-specific case report forms. • Latest version of the American Public • Laboratory test requisition forms. Health Association’s Control of Communicable Diseases Manual (8). • Standardized outbreak questionnaires (available at https://www.cdc.gov/ • Procedures to Investigate Foodborne Illness by the foodsafety/outbreaks/surveillance- International Association for Food reporting/investigation-toolkit.html). Protection (9). • Environmental health assessment forms, • Investigating Foodborne Disease Outbreaks by the such as hand hygiene assessment (examples World Health Organization (10). available at https://www.cdc.gov/nceh/ehs/ • FDA’s Investigations Operations Manual (11). EHSNet). • Shipping protocols, forms and required prepaid labels 2020 | Guidelines for Foodborne Disease Outbreak Response 61
3.4 Response Resources
FSIS online resources • Integrated Food Safety Centers of Excellence all products website: • Template for Including FSIS in Foodborne https://coefoodsafetytools.org/ Illness Outbreak Response Procedures: AllCoEProducts.aspx. www.fsis.usda.gov/OutbreakProcedures. • CIFOR Guidelines: • Information Helpful to FSIS During https://cifor.us/products/guidelines. Foodborne Illness Investigations: 3
www.fsis.usda.gov/InvestigationInfo. BUILDING TEAMS PLANNING AND PREPARATION: • Resources for Public Health Partners: Foodborne Illness Investigation: www.fsis.usda.gov/PHPartners.
3.5 Communication Plans
Good communication is one of the most outbreak, including backups, and contact important factors in successful outbreak people in external agencies (adjacent investigation and control. At all points in the local, territorial, state, tribal, and federal
outbreak continuum—from detection through agencies). Ensure the list includes after-hours investigation and response to debriefing— and weekend contact information, and update communication is critical. Without it, it regularly. investigations and responses can be delayed, uncoordinated, and ineffective. Furthermore, Assemble a contact list of resource persons good communication can help allay agency who have expertise in specific disease agents management and public concerns and and investigation methods with primary phone improve industry support for actions to control numbers and alternates, cell phone numbers, outbreaks. To promote better outcomes, use 24-hour numbers, home phone numbers, the time before and between outbreaks to lay email, fax numbers, and addresses) of the groundwork for communication, such • Core members of the outbreak investigation as developing and updating contact lists, and control team. defining communication processes, establishing • Other officials inside the agency, such as relationships with key persons internal and the chief of the epidemiology unit, director external to the agency, and determining how of the public health laboratory, director confidential information will be stored, and of environmental health, public health whether and how it can be shared. information officer, and the agency director. Although the following practices for • Critical contacts in other government agencies. communication are all recommended, full • Important food industry contacts, including implementation may not be possible in some trade associations (e.g., National Restaurant jurisdictions because of resource limitation. Association). Implementing as many as possible as completely as possible will improve communication. • Key healthcare provider contacts. • Laboratory contacts. 3.5.1 Prepare a list of people in the agency who should be contacted in the event of an • Primary media contacts. 62 Council to Improve Foodborne Outbreak Response
3.5 Communication Plans
3.5.2 Define a formal communication • Create templates for communications with process for the outbreak investigation the public (e.g., press releases, fact sheets), and control team to use during outbreaks. focusing on the most common foodborne Anticipate what information and data response illnesses. Sample materials are available at partners and agency leadership need, and the CIFOR Clearinghouse (https://www. at what frequency, to maintain situational cifor.us/clearinghouse). awareness and guide decision-making about 3 • Create and test online tools to communicate
investigation and control measures. Options with the public (e.g., blast emails, surveys, include daily meetings, daily phone calls, social media). and email updates. Developing a consistent approach to internal communications during • Guide staff on how to respond to and an outbreak helps everyone on the team know communicate during conflict situations, such what to expect. as with upset food service workers, food protection managers, and members of the • Identify the persons responsible for commu- BUILDING TEAMS public. nication on behalf of their organizational unit (epidemiology, environmental health, • Identify people with clinical training, laboratory) and for the outbreak investigation such as public health nurses or medical and control team. Communicators must be epidemiologists, to communicate with case- brought in early as the outbreak develops for patients about the outbreak and actions they PLANNING AND PREPARATION: PLANNING AND PREPARATION: a more efficient response. should take to protect their health and their family’s health. • Determine how nonpublic information will be saved and whether and how it can be • Identify a person from an agency to talk shared. Local and state agencies can receive to the media, ideally someone trained in certain types of confidential information media relations or a public information from FDA under a 20.88 information officer. Establish procedures for coordinating sharing agreement (12,13) (Chapter 7.3). communication with the media to provide consistent messaging and accurate • Distribute a list of the agency’s contacts to information flow. other agencies, and obtain their contacts. • Establish processes for participating in multiagency, multijurisdictional conference calls, and train staff in appropriate conference call etiquette. • Establish procedures for coordinating communication with the following entities to provide consistent messaging and accurate information flow: Local, state, and federal authorities. Local organizations, food industry, and other professional groups (including healthcare providers). The public. The media. 2020 | Guidelines for Foodborne Disease Outbreak Response 63
3.6 Planning for Recovery and Follow-Up
Part of preparing for outbreak response reports that identify lessons learned and action is planning for the recovery and follow-up items for follow-up, including ways to improve. stages. This planning helps ensure appropriate Report the root cause(s) of the outbreak and actions are taken after each outbreak and helps other key investigation findings to national identify and correct problems to prevent future foodborne outbreak and response databases, outbreaks from the same causes. Establish a such as the National Outbreak Reporting process to conduct hot-washes so participants System and the National Environmental 3
can provide feedback. Create after-action Assessment. Reporting System (Chapter 6). BUILDING TEAMS PLANNING AND PREPARATION:
References
1 Food and Drug Administration. FDA Food Code. 8 American Public Health Association. Control of https://www.fda.gov/food/guidanceregulation/ communicable diseases manual. https://ccdm. retailfoodprotection/foodcode/default.htm aphapublications.org/doi/book/10.2105/ 2 Food and Drug Administration. About the CORE CCDM.2745 Network. https://www.fda.gov/food/outbreaks- 9 International Association for Food Protection. IAFP foodborne-illness/about-core-network procedures to investigate foodborne illness. Revised. 3 Food Safety Modernization Act. Pub. L. No. 111–353, https://www.foodprotection.org/about/news-releases/ 124 Stat. 3885 (2011). iafp-procedures-to-investigate-foodborne-illness-revised
4 Association of Food and Drug Officials. RRT best 10 World Health Organization. Foodborne disease practices manual (November 2017 edition). http:// outbreaks: guidelines for investigation and control. www.afdo.org/RRT-Manual https://apps.who.int/iris/handle/10665/43771 5 Food Emergency Response Network. 11 Food and Drug Administration. Investigations https://www.fernlab.org Operations Manual. https://www.fda.gov/ inspections-compliance-enforcement-and-criminal- 6 USDA National Institute of Food and Agriculture. investigations/inspection-references/investigations- NoroCORE: a comprehensive approach to a near operations-manual ‘perfect’ human pathogen. https://nifa.usda.gov/ blog/norocore-comprehensive-approach-near- 12 21 C.F.R. 20.88. perfect-human-pathogen 13 Food and Drug Administration. 7 Qureshi K, Gebbie KM, Gebbie EN. Implementing Information sharing. https://www.fda. ICS within public health agencies. https:// gov/ForFederalStateandLocalOfficials/ ualbanycphp.org/pinata/phics/guide/default.cfm CommunicationsOutreach/ucm472936.htm
Appendix 3.1
Resources (current as of August 8, 2019) • Tennessee Integrated Food Safety Center of Excellence: https://www.cdc.gov/foodsafety/centers/sites/ Academia tennessee.html • Colorado Integrated Food Safety Center of Excellence: • Cornell Department of Food Science: https:// https://www.cdc.gov/foodsafety/centers/sites/ foodscience.cals.cornell.edu colorado.html • Washington Integrated Food Safety Center of • Minnesota Integrated Food Safety Center of Excellence: https://www.cdc.gov/foodsafety/centers/ Excellence: https://www.cdc.gov/foodsafety/centers/ washington.html sites/minnesota.html • American Public Health Laboratories • New York Integrated Food Safety Center of Excellence: https://www.cdc.gov/foodsafety/centers/sites/ newyork.html 64 Council to Improve Foodborne Outbreak Response
Appendix 3.1
Federal Government Food and Drug Administration
• U.S. Department of Agriculture, Food Safety and • FDA Investigations Operation Manual: https://www. Inspection Service: https://www.fsis.usda.gov/wps/ fda.gov/iceci/inspections/iom/default.htm portal/fsis/home • FDA Rapid Response Team Links: RRT Best Practices • FoodSafety.gov: http://www.foodsafety.gov Manual (Edition 2017): http://www.afdo.org/RRT- Manual
3 Centers for Disease Control and • Best Practices for Improving FDA State
Prevention Communications Recalls (Summer 2015): https://www. fda.gov/downloads/ForFederalStateandLocalOfficials/ • Index for Foodborne Illness: https://www.cdc.gov/ ProgramsInitiatives/PartnershipforFoodProtectionPFP/ foodsafety/diseases/index.html UCM460013.pdf • List of Selected Multistate Foodborne Outbreak • Best Practices for Use of FoodSHIELD During Food Investigations: http://www.cdc.gov/foodsafety/ and Feed Incidents (Summer 2015): https://www.fda. outbreaks/multistate-outbreaks/outbreaks-list.html gov/downloads/ForFederalStateandLocalOfficials/
BUILDING TEAMS ProgramsInitiatives/PartnershipforFoodProtectionPFP/ • Foodborne Diseases Active Surveillance Network UCM524721.pdf (FoodNet): http://www.cdc.gov/foodnet/index.html • National Program Standards Crosswalk Resource • The National Molecular Subtyping Network for Paper (September 2013): https://www.fda.gov/ Foodborne Disease Surveillance (PulseNet): downloads/ForFederalStateandLocalOfficials/ https://www.cdc.gov/pulsenet/index.html ProgramsInitiatives/PartnershipforFoodProtectionPFP/
PLANNING AND PREPARATION: PLANNING AND PREPARATION: • CDC Division of Food, Waterborne and Environmental UCM404725.pdf Diseases: http://www.cdc.gov/ncezid/dfwed/ • Model for Local Federal/State Planning • Foodborne Disease Outbreak Surveillance System and Coordination of Field Operations and (FDOSS): https://www.cdc.gov/fdoss/index.html Training (October 2013): https://www.fda.gov/ downloads/ForFederalStateandLocalOfficials/ • National Outbreak Reporting System (NORS): ProgramsInitiatives/PartnershipforFoodProtectionPFP/ https://www.cdc.gov/nors/index.html UCM404722.pdf • System for Enteric Disease Response, Investigation, and • Food/Feed Testing Laboratories Best Practices Coordination (SEDRIC): https://www.cdc.gov/ Manual—Draft (December 2013): https://www.fda. foodsafety/outbreaks/investigating-outbreaks/sedric.html gov/downloads/ForFederalStateandLocalOfficials/ • CDC Vital Signs: https://www.cdc.gov/vitalsigns/ ProgramsInitiatives/PartnershipforFoodProtectionPFP/ • CDC Zoonotic Diseases: UCM404716.pdf http://www.cdc.gov/zoonotic/gi/index.html • Quick Start Food Emergency Response Job Aids • CDC Foodborne Outbreak Team: (Winter 2017): https://www.fda.gov/downloads/ http://www.cdc.gov/ncezid/dfwed/orpb/ort.html ForFederalStateandLocalOfficials/ProgramsInitiatives/ PartnershipforFoodProtectionPFP/UCM535097.pdf • Salmonella Reporting Timeline: http://www.cdc.gov/ salmonella/reportingtimeline.html Other Organizations • National Antibiotic Resistance Monitoring System for Enteric Bacteria (NARMS): • Association of Public Health Laboratories https://www.cdc.gov/narms/index.html APHL and Food Safety: https://www.aphl.org/ • Norovirus information: programs/food_safety/Pages/APHL-Food-Safety. http://www.cdc.gov/norovirus/index.html aspx • Burden of Foodborne Illness: Findings: http://www.cdc. Food Safety Tools and Resources: https://www. gov/foodborneburden/2011-foodborne-estimates.html aphl.org/programs/food_safety/Pages/Food- • National Environmental Assessment Reporting System Safety-Tools-and-Resources.aspx (NEARS) (https://www.cdc.gov/nceh/ehs/nears/index. Food Safety: https://www.aphl.org/programs/ htm) Integrated Food Safety Centers of Excellence: food_safety/Pages/default.aspx https://www.cdc.gov/foodsafety/centers/index.html 2020 | Guidelines for Foodborne Disease Outbreak Response 65
Appendix 3.1
• Association of Food and Drug Officials: • National Association of County and City Health http://www.afdo.org Officials: https://www.naccho.org • Association of State and Territorial Health Officials: • National Association of State Departments of https://www.astho.org Agriculture: https://www.nasda.org • Council of State and Territorial Epidemiologists: • National Association of State Public Health http://www.cste.org Veterinarians: http://www.nasphv.org
• International Association for Food Protection: • National Environmental Health Association: 3 https://www.foodprotection.org https://www.neha.org BUILDING TEAMS PLANNING AND PREPARATION: • International Food Protection Training Institute: https://ifpti.org
CHAPTER 4
Foodborne Illness Surveillance and Outbreak Detection
CHAPTER SUMMARY POINTS
• Two general methods are used to detect most outbreaks: pathogen-specific surveillance and complaint systems. • Recent technology changes have altered foodborne illness surveillance, including culture-independent diagnostic testing (CIDT) and whole-genome sequencing (WGS). Molecular multitarget CIDTs that can detect up to 22 pathogens in an hour are replacing enteric pathogen culture in many clinical laboratories, shifting the burden of isolating bacteria for subtype and other characterization to public health laboratories. WGS offers major improvements over traditional subtyping methods but currently takes longer than pulsed-field gel electrophoresis to complete, leading to potential delays in identification of clusters. • The usefulness of consumer complaint systems to identify outbreaks is based either on: 1) the ability of groups with a common exposure to self-identify illness and link it to the exposure; or 2) the ability of the complaint system to independently link multiple independent complaints to a common source. To complement the review of individual complaints and patterns of complaints detected through the foodborne illness complaint system, communicable disease surveillance staff should conduct standard interviews for foodborne illness detected through pathogen-specific surveillance (e.g., Salmonella and Shiga toxin–producing Escherichia coli). Regardless of who receives the complaint or how the complaint is received (phone, online), the complaint should be evaluated for the likelihood of a foodborne illness or outbreak associated with the establishment that is the subject of the complainant or other establishments identified in the food history.
URLs in this chapter are valid as of August 13, 2019. 68 Council to Improve Foodborne Outbreak Response
4.0 Introduction
4.0.1 Foodborne illness surveillance Although these methods are presented identifies clusters of illness that may separately for descriptive purposes, they be caused by a common food source. are most effective when used together This chapter reviews major features, and integrated with food, veterinary, and strengths, and limitations of surveillance environmental monitoring programs methods and provides recommendations (Chapters 4 and 5). The range of possible for increasing the effectiveness of each. food vehicles detectable through foodborne In practice, detecting individual foodborne illness surveillance includes all food or other illness outbreaks involves multiple approaches. substances contaminated at any link in the However, in general, two methods are used chain from production to ingestion. Foodborne to detect most outbreaks: pathogen-specific illness surveillance complements regulatory
4 surveillance and complaint systems (Table 4.1). and commercial monitoring programs A third method, syndromic surveillance, is used by providing primary feedback on the in some jurisdictions, but its role in detecting effectiveness of prevention programs. foodborne illness outbreaks is limited. 4.0.2 This chapter highlights how • Pathogen-specific surveillance: Healthcare recent technology changes have altered providers and laboratorians report individual foodborne illness surveillance; including cases of illness when selected pathogens, the use of culture-independent diagnostic such as Salmonella enterica and Escherichia coli testing (CIDT) and whole-genome O157:H7, or specific clinical syndromes, sequencing (WGS). Molecular multitarget such as hemolytic uremic syndrome and CIDTs can detect up to 22 pathogens in an botulism, are identified. Public health hour, which makes them very attractive for AND OUTBREAK DETECTION professionals gather exposure information clinical laboratories (1). Molecular multitarget through interviews with case-patients. CIDTs are replacing enteric pathogen • Complaint systems: Healthcare providers culture in many clinical laboratories. The
FOODBORNE ILLNESS SURVEILLANCE FOODBORNE ILLNESS SURVEILLANCE or the public identify and report suspected use of CIDTs in clinical laboratories shifts illness clusters (group notifications) or the burden of isolating bacteria for subtype individual complaints. Exposure information and other characterization to public health is acquired by interviews with ill people. laboratories (PHLs). Another major change • Syndromic surveillance: This surveillance is the advancement of WGS at PHLs. WGS method generally involves systematic (usually has replaced traditional methods used at automated) gathering of data on nonspecific PHLs, such as serotyping and subtyping by health indicators that might reflect increases pulsed-field gel electrophoresis (PFGE), for the in illness, such as purchase of loperamide primary foodborne pathogens under routine (an antidiarrheal agent), visits to emergency surveillance. departments for diarrheal complaints, or calls to poison control hotlines. Exposure information is not routinely collected. 2020 | Guidelines for Foodborne Disease Outbreak Response 69
4.0 Introduction SYNDROMIC Variable* Low† Limited to syndromes (or indicators) under surveillance in health Trend indicator different expected, from space/time clusters of diagnosed cases High§ Low** 4 AND OUTBREAK DETECTION FOODBORNE ILLNESS SURVEILLANCE INDIVIDUAL COMPLAINT Fast Intermediate although effectiveness Any, limited to agents with short incubation periods‡ Multiple independent reports in with common exposures space or time unique clinical by the recognized presentation the reports agency receiving Low to moderate Low to moderate (after interview of case-patients and collection food history) appropriate COMPLAINT A high signal-to-noise ratio means that even a small number of cases stand A low ratio means a cluster of cases or out against a quiet background. because it is lost in the many other similar events is difficult to perceive cases or events happening simultaneously—similar to a weak radio signal surveillance is lost in static noise. The signal-to-noise ratio for syndromic lowest for nonspecific health indicators, such as loperamide use or visits department with diarrheal disease complaints. The ratio to the emergency information. specificity of agent or syndrome For with increasing increases the signal- such as botulism-like syndrome, syndromes, highly specific, rare that of pathogen-specific surveillance. to-noise ratio would approach ¶ not typically obtained. histories are **Exposure SURVEILLANCE METHOD (after interview of ¶ GROUP NOTIFICATION Fast Intermediate Any‡ illnesses Report of group by healthcare recognized or the laboratory, provider, public Low High case-patients and collection food history) of appropriate PATHOGEN-SPECIFIC (after interview of case-patients ¶ Relatively slow High Limited to clinically suspected or laboratory-confirmed diseases under surveillance Cluster of cases in space or time with common agent Low to moderate High food and collection of appropriate history). Even higher when combined with subtyping
Comparison of Foodborne Illness Surveillance Systems OF METHOD FUNCTIONAL CHARACTERISTIC An advantage in speed is limited mainly to nonspecific health dicators (preclinical and clinical prediagnostic data). Data must be analyzed, and and clinical prediagnostic (preclinical including comparison with standard a follow-up investigation is required, public health action can be taken. surveillance, before Sensitivity is higher for rare, specific syndromes, such as botulism-like specific syndromes, Sensitivity is higher for rare, syndrome. linking can be detected without an identified etiology, Although outbreaks agent information. may require to a common source multiple outbreaks to the a meaningful signal is related The number of cases needed to create an advantage in speed also Indicators that offer specificity of the indicator. tend to have low specificity. Table 4.1. Table Inherent speed of outbreak speed of outbreak Inherent detection Sensitivity to widespread, low-level contamination events (best practices used) of outbreaks Types (etiology) that method can potentially detect signal (at Initial outbreak public health level) No. cases needed to create initial signal Signal-to-noise ratio * † ‡ § 70 Council to Improve Foodborne Outbreak Response
4.1 Pathogen-Specific Surveillance
4.1.1 The purpose of pathogen-specific Legacy systems, such as telephone, mail, or surveillance is to systematically collect, fax reporting, also are used but are slower analyze, and disseminate information and more labor intensive and error prone. about laboratory-confirmed illnesses • Isolates or other clinical materials are or well-defined syndromes as part forwarded from clinical laboratories serving of prevention and control activities. primary healthcare facilities to PHLs for Surveillance for typhoid fever began in 1912 confirmation and further characterization, and was extended to all Salmonella spp. in as required by state laws or regulations or as 1942. National serotype-based surveillance of requested by the local jurisdiction. Salmonella began in 1963, making it one of the oldest pathogen-specific surveillance programs Molecular multitarget CIDTs are replacing
4 and the oldest PHL subtype-based surveillance enteric pathogen culture in many clinical system. The usefulness of pathogen-specific laboratories. Many clinical laboratories surveillance is related to the specificity that perform enteric pathogen detection with which agents are classified (i.e., use of using CIDTs do not culture the pathogens subtyping and method), enabling grouping identified by the CIDT. Instead, the clinical of individual cases of illness with other cases laboratory sends the specimen to the PHL most likely to share a common food source to perform culture to obtain an isolate or other exposure. The utility of bacterial for further testing, which is important for surveillance increased during the 1990s with foodborne disease surveillance. the development of PulseNet and molecular It is imperative that clinical laboratories send subtyping of selected foodborne pathogens, the specimens in a transport media (e.g., including Salmonella, Shiga toxin–producing AND OUTBREAK DETECTION Box 4.1. Selected Nationally Notifiable E. coli (STEC) O157:H7, Shigella, and Listeria. Diseases that Can be Foodborne Additional gains in usefulness are anticipated with the adoption of WGS in 2019. • Anthrax (gastrointestinal)
FOODBORNE ILLNESS SURVEILLANCE FOODBORNE ILLNESS SURVEILLANCE • Botulism, foodborne 4.1.2 Most illnesses included under • Campylobacterosis pathogen-specific surveillance are • Cholera reportable (i.e., notifiable) diseases. State • Cryptosporidiosis • Cyclosporiasis or local health agencies establish criteria • Giardiasis for voluntary or mandatory reporting of • Hemolytic uremic syndrome, postdiarrheal infectious illnesses, including those that might • Hepatitis A virus infection be foodborne (Box 4.1). These criteria describe • Listeriosis the illnesses to report, to whom, how, and in • Salmonellosis what timeframe. For this type of surveillance, • Shiga toxin–producing Escherichia coli infection illnesses are defined by specific laboratory • Shigellosis findings or by well-defined syndromes, such as • Trichinellosis (trichinosis) • Typhoid fever hemolytic uremic syndrome. • Vibrio infection • Illnesses are reported primarily by In addition, the following are nationally notifiable: laboratories, medical staff (e.g., physicians, • Foodborne illness outbreaks infection-control practitioners, medical • Waterborne illness outbreaks records clerks), or both. Reports can be Source: Centers for Disease Control and automatically generated from an electronic Prevention. Nationally Notifiable Infectious medical record or laboratory information Diseases. United States 2018. Historical. https:// system or reported through a secure website. wwwn.cdc.gov/nndss/conditions/notifiable/2018 2020 | Guidelines for Foodborne Disease Outbreak Response 71
4.1 Pathogen-Specific Surveillance
Cary Blair) to PHLs immediately to improve systems, such as Laboratory-based Enteric- the chances of isolating the pathogen. Diseases Surveillance). Immediate transport of specimens also • PHLs issue reports either singly or in helps identify potential clusters as soon as groups to the epidemiology department possible. The Association of Public Health either through electronic systems such as Laboratories has produced guidelines for laboratory information management system specimen submission for optimal isolate submission to the epidemiology database or recovery from specimens that test positive for manual entry. Reports also may be issued to pathogens by CIDTs (2). submitters as permitted by local policies. 4.1.3 Laboratory staff record receipt • Rapid identification of clusters in the of samples at the PHL and enter laboratory and communication of the cluster 4 sample information into the laboratory to foodborne illness epidemiologists is vital AND OUTBREAK DETECTION FOODBORNE ILLNESS SURVEILLANCE information management system, or to outbreak detection. Case cluster data are LIMS. This process facilitates downstream enhanced by inclusion of information about information sharing with investigation matching isolates or outbreaks through partners. Patient information submitted PulseNet from other jurisdictions and by with the sample may be provided to the matching isolates from food, animal, or epidemiology department for comparison environmental monitoring tests that provide with information from cases already reported information for hypothesis generation. and to enable reconciliation of case reports and laboratory samples and identification of 4.1.4 WGS has replaced traditional previously unreported cases. methods used at PHLs, such as serotyping using antiserum and subtyping PFGE. • If CIDTs have been used to detect the PFGE has been the predominant subtyping pathogen in the clinical laboratory, and a method for PulseNet since its inception in specimen is submitted, the PHL attempts to 1996, but was replaced by WGS in 2019 (3). isolate that pathogen. • WGS data generated from isolates are • Once the isolated pathogen is identified, it analyzed to compare isolate relatedness is further characterized (e.g., by serotyping, (Figure 4.1). Generally, this comparison is virulence assays, molecular subtyping, or done using the complementary approaches antimicrobial susceptibility tests). of high-quality single-nucleotide • WGS and PFGE (if conducted at the polymorphism (hqSNP) analysis and core or state level) data, along with accompanying whole-genome multilocus sequence typing metadata, are uploaded to local and national (cg/wgMLST). hqSNP analysis identifies PulseNet databases. Consolidated daily differences in single base pairs between reports, such as subtype frequency reports, closely related isolates, whereas cg/wgMLST often are used to facilitate cluster recognition. analysis relies on a database of all potential These reports may be automatically genes, or loci, for a particular enteric generated by laboratory or epidemiology pathogen. cgMLST looks at those genes in information systems, extracted from the common between all isolates being compared PulseNet database, or extracted from the and primarily is used for surveillance and System for Enteric Disease Response, outbreak detection, whereas wgMLST looks Investigation and Coordination (SEDRIC). at both the genes in common and those that • Specimen data (including detailed subtyping represent the diversity of the strains and is results) are uploaded to national surveillance used to further characterize isolates that are 72 Council to Improve Foodborne Outbreak Response
4.1 Pathogen-Specific Surveillance
Figure 4.1. Depiction of Whole-Genome Sequencing (WGS) and Sequencing Analysis. WGS starts with extracted DNA from isolated bacteria. Library preparation is then performed by sequencing, which creates millions of short reads. The reads are combined to create long strands of DNA. DNA from one bacterium can be compared with others using the complementary approaches of high- quality single-nucleotide polymorphism (hqSNP) analysis and core genome multilocus sequence typing (cgMLST). hqSNP analysis identifies differences in single base pairs among closely related isolates, and the cgMLST analysis relies on a database of all potential genes, or loci, for a particular enteric pathogen. Both approaches identify differences between compared isolates and can be used to assign a threshold of genetic relatedness between isolates: for hqSNP isolates, it is a number of SNP, or base pair, differences; and for cgMLST, it is the number of allele, or gene, differences. A phylogenetic tree can be used to visualize the genetic differences using either SNP-based testing or cgMLST. 4 WGS Sequencing analysis
Bacteria isolates hqSNP analysis ( ■ : Location of SNPs compared to reference genome Isolate A Isolate B Isolate C Isolate D Reference genome DNA extraction cgMLST ( ■ ■ ■ ■ : Location of SNPs, insertions or deletions)
Locus 1 Locus 2 Locus 3 Locus 4 Isolate A Allele1 Allele2 Allele10 Allele1 Isolate B Allele1 Allele2 Allele10 Allele1
AND OUTBREAK DETECTION Isolate C Allele3 Allele1 Allele21 Allele5 Isolate D Allele1 Allele7 Allele10 Allele1 Library prep and sequencing
Phylogenic tree
FOODBORNE ILLNESS SURVEILLANCE FOODBORNE ILLNESS SURVEILLANCE Isolate A Isolate B Short reads contigs Isolate D Isolate C
related and part of a cluster. Both of these Generally, PulseNet uses a definition of at approaches identify differences between least 3 cases within a 60-day window with compared isolates and can be used to assign 0–10 allele differences, where at least 2 of the a threshold of genetic relatedness between cases differ by 5 or fewer alleles, forSalmonella isolates. For hqSNP isolates, the threshold of and STEC. PHLs may consider a narrower relatedness is a number of SNP, or base pair, definition (such as 0–5 alleles) to reduce the differences; for cg/wgMLST it is the number number of clusters that need to be investigated of allele, or gene, differences. Both methods and to focus investigation resources. Similar can produce a phylogenetic tree, which aids to PFGE, there can be common sequence in interpretation of results. types or rare sequence types, which should be • Several “rules of thumb” based on the number considered during cluster investigations. In of allele differences have been developed to addition, if the outbreak occurs over a long help define a cluster by WGS. These rules period or is zoonotic, more allele differences vary by pathogen and mode of transmission. are detected than in an outbreak representing 2020 | Guidelines for Foodborne Disease Outbreak Response 73
4.1 Pathogen-Specific Surveillance
a point source contamination event. When the genetic relatedness of the isolates. For an outbreak source is contaminated with example, isolates A and B that have the same multiple diverse sequence types, known as allele code, 1.1.1.1.1, are closely genetically a polyclonal outbreak, sequence data may related; a new isolate, isolate C, that has be used to identify multiple independent allele code 1.1.1.1.2 is more closely related clusters, which can then be used to identify than isolate D, with allele code 1.1.1.2.2. the polyclonal outbreak. One strategy is to Additionally, the allele code can be used to use a narrow cluster definition to identify identify clusters and combined with other clusters. That strategy will reduce the number information predicted from the WGS data, of misclassified cases and will increase the including virulence, serotype, and predicted measure of association. Once an outbreak antibiotic resistance, can be used to prioritize 4 is identified, the cluster definition can be cluster follow-up as part of the triage expanded to identify addition cases that were process. A recent review provides additional AND OUTBREAK DETECTION FOODBORNE ILLNESS SURVEILLANCE missed because of the initial stringent cluster information on use and interpretation of definition. WGS data for surveillance (3). • cgMLST analyses are built from a stable • WGS data can be used to identify an database of genes so a pattern name, or organism, predict serotype and antibiotic allele code, can be assigned to the sequence resistance, and identify virulence genes. data (Figure 4.2). Allele codes are built from There are several tools for conducting these a single linkage tree of all isolates for an analyses, including tools available through organism, and cutoffs are set along certain the PulseNet database system. points, which represent percentage similarity • Although WGS offers major improvements cutoffs, along the tree that produce a stable over traditional subtyping methods and nomenclature and provide enough resolution enables PHLs to have more efficient to identify potential outbreak clusters. workflows, some challenges exist to using Using the allele code, which is a string of this technology in public health practice. 5–7 numbers, similar to a ZIP code, closely WGS takes longer than PFGE to complete related isolates can be identified and historic (a minimum of 4 days for WGS vs. 1 day frequencies can be tracked. Each shared for PFGE). In addition, if WGS replaces number along the allele code indicates
Figure 4.2. Depiction of Allele Code Assembly.
Nomenclature is organism-specific with different thresholds for the digits. Allele code 51 Alleles 19 Alleles 0 Alleles Organism-specific allele codes are built 71 Alleles 36 Alleles 7 Alleles from a string of 5–7 numbers, similar to a ZIP code. Each shared number along the allele code indicates the genetic LMO1.0 - 5 . 1 . 1 . 2 . 5 . 1 relatedness of the isolates. When sequences have partial names, they Organism version Allele code are singletons in clusters below their last digit. For example, isolates A and B are Listeria monocytogenes isolates Isolate A that are approximately within 36 and LMO1.0 - 5 . 1 . 2 19 alleles of each other. Isolate B LMO1.0 - 5 . 1 . 2 . 2 . 5 . 1 74 Council to Improve Foodborne Outbreak Response
4.1 Pathogen-Specific Surveillance
traditional serotyping methods, identification (stripped of individual identifiers) when they of clusters using serotype is delayed. PHLs are sent outside the reporting states. need to perform WGS in a timely manner to ensure clusters are identified as soon as 4.1.6 Initial cluster identification and possible, which can be difficult to do in a cluster assessment might occur as cost-efficient manner if the testing level of a two processes conducted, respectively, jurisdiction is low. by the laboratory and epidemiology departments or might occur as a single 4.1.5 Case-patients are usually interviewed process within epidemiology. Agent, time, one or more times about potential and place are examined individually and in exposures and additional clinical and combination to identify possibly significant
4 demographic information. Routine clusters or trends. This is the critical first step collection of detailed exposure information as in hypothesis generation. Clusters of unusual soon as possible after reporting (either CIDT- exposures, exposure frequencies, demographic or culture-positive result) maximizes exposure distributions (e.g., predominance of cases recall, provides a basis for rapid cluster in a particular age group), or connection to investigation, is critical to the environmental food, animal, or environmental monitoring investigation, and is strongly recommended studies might be identified. Clusters of cases for high-consequence enteric pathogens, such are examined as a group and, if a common as STEC O157:H7, Salmonella, and Listeria exposure seems likely, are investigated further monocytogenes. (Chapter 5). In some jurisdictions, cluster • The scope of routine interviews varies by detection and triage are a laboratory function jurisdiction, agent, and type of test result. (see section 4.2.5). AND OUTBREAK DETECTION Initial interviews typically cover basic • A cluster is defined as two or more cases descriptive information and exposures of of disease linked by place, time, pathogen local importance, such as attendance at subtype, or other characteristic. Isolates FOODBORNE ILLNESS SURVEILLANCE FOODBORNE ILLNESS SURVEILLANCE a childcare facility, occupation as a food closely related by genetic subtyping are worker, and medical follow-up information. more likely to share a common source than Whereas many local agencies collect isolates that are not closely related by genetic information about a limited set of high- subtyping. risk exposures, where resources are limited, • Clusters may be more or less recognizable detailed exposure interviews might be and more or less actionable. This chapter conducted only when clusters are investigated focuses on case clusters and outbreaks, or outbreaks are recognized (Chapter 5). but for some high-consequence agents Information the public health agency receives or syndromes (e.g., botulism or paralytic through multiple avenues, including basic shellfish poisoning), even a single case might clinical and demographic data from individual merit a prompt and aggressive public health case-patients of specific laboratory-confirmed response. illness or well-defined syndromes, is reconciled • Clusters are common and pursuing them and linked with case isolates or other clinical all with equal vigor is not practical or materials received in the PHL. Reconciled case productive. Laboratory staff often identify reports are forwarded to higher jurisdictional clusters when they detect an increase of levels (local health agency to state agency, a specific subtype or serotype. Incoming state agency to federal agency) by a variety of surveillance data are evaluated for unusual mechanisms. In general, records are redacted case counts based on historical frequencies 2020 | Guidelines for Foodborne Disease Outbreak Response 75
4.1 Pathogen-Specific Surveillance
(accounting for seasonality), the severity of simple best practices. For many organisms, disease, and molecular matches between clusters identified by WGS are more human cases and food or animal monitoring indicative of a close genetic relationship samples. In general, cases clustered over and epidemiologic relatedness than are a relatively short period are more likely to clusters identified by PFGE. An increase in indicate an outbreak. The time window frequency of a strain is only one indication of used to delimit clusters varies by agent. For a potentially significant cluster. Furthermore, example, a wider window is used to evaluate absence of an increase in case numbers from clustering of listeriosis cases than to evaluate expected values does not rule out significance. salmonellosis cases because of differences in the natural history of each disease. 4.1.7 The timeline for pathogen-specific surveillance covers a series of events from 4 • Although cluster recognition software the time a person is infected through the AND OUTBREAK DETECTION FOODBORNE ILLNESS SURVEILLANCE TM packages, such as SaTScan , cumulative time public health officials determine summary (cusum) outbreak detection that person is part of a disease cluster. algorithms, and query algorithms in the The time from infection to cluster detection System for Enteric Disease Response, is one of the limiting factors of pathogen- Investigation and Coordination have been specific surveillance. Minimizing delays by developed, none have yet been validated streamlining the individual processes improves for broad-based enteric disease data. The the likelihood of overall success. A sample decision to report or pursue a cluster is an timeline for Salmonella case reporting is important part of the outbreak detection presented in Figure 4.3. process but not one that is easily distilled into
Figure 4.3. Sample Timeline for Salmonella Case Reporting*
Person eats contaminated food Incubation time = 1-4 days Person becomes ill Time to contact with care provider = 1-3 days
Fecal sample collected Time to diagnosis using culture = 2-3 days Time to diagnosis using CIDT = 0-1 day Sample tests positive for Salmonella Shipping time = 1-3 days Isolate or specimen received at the PHL Time from isolate = 0-1 days Time from specimen = 2-3 days Identification of isolated pathogen Time to characterization* = 4-10 days
Characterization completed at PHL
*Time to complete characterization from an isolate: • WGS = 4-10 days (can be performed in parallel to serotyping, if needed) • PFGE=1 day (can be performed in parallel to serotyping) • Traditional serotyping = 2 days
*Abbreviations: CIDT, culture-independent diagnostic testing; PFGE, pulsed-field gel electrophoresis; PHL, public health laboratory; WGS, whole-genome sequencing. 76 Council to Improve Foodborne Outbreak Response
4.1 Pathogen-Specific Surveillance
• Incubation time: the time from ingestion Salmonella to isolation and confirmation of of a contaminated food to beginning of Salmonella. Specimens identified asSalmonella symptoms. For Salmonella, this typically by CIDTs require culture to isolate the is 1–4 days, sometimes longer. For organism from clinical samples that were more information about incubation used to perform CIDT, which takes 2–3 times (also called incubation periods) of days. If culture-based methods are used at foodborne pathogens see the Outbreaks of the clinical laboratory, the isolated bacteria is Undetermined Etiology (OUE) Agent list confirmed at the PHL, which takes 1 day. from the CIFOR website (https://cifor.us) • Time to pathogen characterization: and the recent analysis of median incubation The time required for state public health periods in outbreaks (4). authorities to serotype and to perform 4 • Time to contact with healthcare provider subtyping on the Salmonella isolate and or doctor: the time from the first symptom compare it with the outbreak pattern. to medical care (when a fecal sample will Serotyping typically takes 3 working days but ideally be collected for laboratory testing). can take longer. PFGE can be accomplished This time may be an additional 1–3 days, in 1 working day (24 hours), whereas sometimes longer. WGS can take as little as 4 working days. • Time to diagnosis: the time from provision However, many PHLs have limited staff and of a sample to laboratory identification space and experience multiple emergencies of the agent in the sample as Salmonella. simultaneously. In practice, serotyping and CIDT tests often produces same-day results, PFGE or WGS subtyping may take several whereas culture-based diagnostic methods days to several weeks in extreme cases. Data AND OUTBREAK DETECTION take 2–3 days. derived from WGS can be used to determine the serotype and subtype and predict the • Sample/isolate shipping time: the time antibiotic resistance profile of an isolate, required to ship the Salmonella isolate or thereby streamlining laboratory processes FOODBORNE ILLNESS SURVEILLANCE FOODBORNE ILLNESS SURVEILLANCE positive specimen from the initial testing into a single workflow. However, completion laboratory to the public health authorities of WGS will take longer than traditional who will perform serotyping and subtyping. workflows. Additionally, most or all PHLs This usually takes 1–3 days or longer, will have to perform some batching to depending on transportation arrangements reduce the cost of the sequencing. Batching within a state and distance between the should be minimized as much as possible, clinical laboratory and the public health however, because faster turnaround for department. Diagnostic laboratories are pathogen characterization is highly desirable. not required by law in many jurisdictions to forward Salmonella isolates to PHLs, and • The total time from onset of illness to not all diagnostic laboratories forward any confirmation of the case as part of an isolates unless specifically requested to do so. outbreak is typically 2–3 weeks. When a laboratory does submit an isolate 4.1.8 Routine testing for specific pathogens or specimen to public health, the timeframe of food in production is conducted as for submission is often based on convenience part of larger food-safety verification and cost effectiveness rather than public programs operated by the Food and Drug health considerations. Administration (FDA), U.S. Department of • Confirming isolated pathogen: The Agriculture (USDA), and state agriculture time after a sample has tested positive for agencies. 2020 | Guidelines for Foodborne Disease Outbreak Response 77
4.1 Pathogen-Specific Surveillance
• WGS is routinely performed on food isolates 4.1.9 A key strength of pathogen-specific from FDA- and USDA-regulated products surveillance is its ability to detect as part of the GenomeTrakr program, and widespread disease clusters initially the sequence data and limited metadata are linked only by a common agent. Most uploaded to a genomic database housed at national and international foodborne disease the National Institutes of Health, National outbreaks are detected in this manner. Center for Biotechnology Information (NCBI) as well as to PulseNet. On NCBI, Combining specific exposure information with GenomeTrakr sequences are compared case information from clusters recognized with sequences from the Centers for Disease though complaints makes pathogen-specific Control and Prevention and other federal, surveillance the most sensitive method for 4 academic, and international public health detecting unforeseen problems in food- and agencies; closely related isolates identified on water-supply systems caused by the agents AND OUTBREAK DETECTION FOODBORNE ILLNESS SURVEILLANCE the NCBI Pathogen Detection Portal (5) can under surveillance. The specificity of agent or be potential leads for cluster sources. syndrome information combined with specific exposure information obtained by interviews • Incorporating this routine food or animal enables the positive association of small monitoring or regulatory surveillance numbers of cases with exposures. test data into the disease surveillance information stream enhances hypothesis 4.1.10 A key limitation of pathogen-specific generation and improves the sensitivity and surveillance is that it works only for timeliness of outbreak detection. In the diseases detected by routine testing and United States, data streams from human reported to a public health agency. disease surveillance, food-testing programs, • Pathogen-specific surveillance is relatively environmental sources, and selected slow because of the many steps required live-animal testing are co-mingled in the (Figure 4.1). PulseNet database; however, important product details might not be readily • Subtype-specific surveillance requires an available. isolate, which is challenging because of the use of CIDTs in clinical laboratories.
4.2 Complaint Systems
Consumer complaint systems are an effective is based on 1) the ability of groups with a surveillance tool for detecting a variety of common exposure to self-identify illness food-related incidents, including reportable and link it to the exposure or 2) the ability pathogens. Notification or complaint systems of the complaint system to independently are intended to provide agencies with a tool link multiple independent complaints to for documenting, evaluating, and responding a common source. Complaints involving to reports from the community about possible multiple households, instances of multiple foodborne disease events. The information independent complaints about the same food maintained in these systems also helps to establishment, reports of clusters of illness, conduct prevention and control activities. and complaints involving multiple people in the same household that suggest an exposure 4.2.1 The usefulness of consumer outside the home often indicate an outbreak complaint systems to identify outbreaks and should be evaluated to determine whether 78 Council to Improve Foodborne Outbreak Response
4.2 Complaint Systems
an investigation is warranted. In the absence of complainant information. Complaints common, suspicious exposures shared by two received through other formats may warrant or more case-patients, complaints of individual additional follow-up to fully document the illness with nonspecific symptoms—such as complaint. diarrhea or vomiting—generally are not worth • Questions should cover name and contact pursuing. Thus, sufficient exposure information information of the caller, detailed illness about every independent complaint should be information (including exact time of collected because reported exposures might symptom onset and recovery), suspected food become more significant when also reported product and product packaging information by subsequent complainants. Complaint (if applicable), name and location of retail or reporting involves passive collection of reports restaurant establishment, names and contact 4 of possible foodborne illness from individuals information of other members of the dining or groups, such as the following: party (if applicable), and all potentially • Reports from any individual or group who relevant nonfood exposures. observes a pattern of illness affecting a • When illness is limited to a single person group of people, usually after a common or members of a single household, obtain exposure: Examples include reports of illness food history for the 3 days before onset that among multiple persons eating at the same focuses on meals eaten outside of the home. restaurant or attending the same event and People often identify an incorrect exposure reports from healthcare providers of unusual as the cause of their illness, often attributing patterns of illness, such as multiple patients it to the last thing they ate. However, only with bloody diarrhea in a short time span. one in five complaints with a known etiology AND OUTBREAK DETECTION • Multiple independent complaints about is caused by an agent with an incubation illness in single persons or households. Group period shorter than 24 hours. illness and independent complaints can be A food history of at least 3 days before FOODBORNE ILLNESS SURVEILLANCE FOODBORNE ILLNESS SURVEILLANCE used together and linked with data obtained illness onset should be collected for through pathogen-specific surveillance. In individual complaints because common contrast to pathogen-specific surveillance, exposures are the sole mechanism to link complaint reporting does not require cases. A standardized form that includes identification of a specific agent or syndrome both food and nonfood exposures is or contact with the healthcare system. preferred. 4.2.2 Detection of outbreaks based on Complaint systems that rely on Web- multiple individual complaints requires based reporting or other means of self- a system for recording complaints and reporting should also ask for a 3-day food comparing food histories and other history, with emphasis on meals eaten exposures reported by individuals. All outside the home; and should request complaints require some level of follow-up. contact information in case additional A telephone caller should be given some information is needed. expectation for what follow-up is likely. A Efforts to capture complaints using social person sending a complaint by text, email, or media should incorporate a link to online online reporting system should be notified the reporting, an online survey, or a phone complaint was received. number to the health department. • Document complaints received by telephone Given the ubiquity of norovirus with a standard intake form to record infections, pay particular attention to 2020 | Guidelines for Foodborne Disease Outbreak Response 79
4.2 Complaint Systems
exposures in the 24–48 hours before onset illness complaint system, conduct whenever norovirus is suspected. As more standard interviews for foodborne illness information about the likely etiologic agent cases detected through pathogen-specific is collected, this approach can be modified. surveillance (e.g., Salmonella and STEC). Enter all food establishments at which affected The complaint and subsequent interviews persons reported eating within the 7 days can lead to a hypothesis about the pathogen before illness onset into the complaint database. that leads to a different time frame for the Routinely examine a list of restaurants reported exposure history (e.g., vomiting leads to a by complainants and case-patients in pathogen- different hypothesis and exposure history specific surveillance to search for common time frame than does bloody diarrhea). establishments. • When illness is reported among members 4
of multiple households, collect information Complaint data and results of pathogen- AND OUTBREAK DETECTION FOODBORNE ILLNESS SURVEILLANCE only for meals in common to members of the specific surveillance are much easier to link if different households. Attempt to contact and complaint systems are centralized at the same interview ill meal companions reported by jurisdictional level as pathogen-specific disease the original caller about symptoms and food surveillance. The link of data from pathogen- consumption. specific and complaint surveillance systems can occur at the level of the local health agency or Focus interviews on the event shared by between individual city-based environmental members of the group. However, be aware health staff and county-based communicable they might have more than one event in disease program or at the state level. Such a common and explore that possibility. shared/centralized system should enhance the Ask about other possible exposures for ability of agencies to detect and respond to the interviewee or for others he or she possible foodborne outbreaks but should not might have contacted, such as childcare prevent any participating jurisdiction from attendance, employment as a food worker, fulfilling whatever role is required by law or is or ill family members. determined to be necessary to protect health in the jurisdiction’s area. • Enter all information collected into the complaint database. Review interview data 4.2.4 Environmental health assessment regularly to look for trends or commonalities. and follow-up is generally managed As part of the review of the data, consider by environmental health staff at local running reports showing frequencies of health departments that also license and specific restaurants or other exposures (such inspect restaurants and other food-service as recreational water venues). establishments.
• Set up the reporting process so all reports In jurisdictions where visits are not required to go through one person or one person every restaurant named in illness complaints, routinely reviews reports. Centralization of the investigation and control team must decide the reporting or review process increases the whether investigation of a commercial food likelihood that patterns among individual establishment is likely to be beneficial. To complaints and seemingly unrelated make this decision, consider details of the outbreaks will be detected. complainant’s illness and the foods eaten at the establishment (Box 4.2). 4.2.3 To complement the review of individual complaints and patterns of • If communicable disease surveillance staff complaints detected through the foodborne receive the complaint, they should immedi- 80 Council to Improve Foodborne Outbreak Response
4.2 Complaint Systems
ately share the complaint information with between local health agencies and state the responsible environmental health staff. departments of agriculture or health, and • Regardless of who receives the complaint or between local health agencies and state how the complaint is received (e.g., phone, agencies and federal agencies: USDA’s Food online), the complaint should be evaluated Safety and Inspection Service (USDA-FSIS) for the likelihood of a foodborne illness or for meat, poultry, and egg product–related outbreak associated with the establishment complaints and FDA for complaints related that is the subject of the complaint or with to other food items. other establishments listed in the food history. • Nongovernment complaint systems that do In addition, environmental health staff not share all information with the appropriate should review the establishment’s inspection jurisdiction(s) and that do not have the 4 history, contact the establishment’s manager, authority to investigate the complaint and determine the value of conducting an (inspect the establishment or conduct an environmental assessment. Additional steps, epidemiologic investigation) are not useful if such as an inspection, may be unnecessary the goal is to protect the public’s health. Such if the complaint involves only one person systems should clearly state that the complaint (or persons in one household) and the illness is not being filed with an agency that can reported is inconsistent with an exposure act on the complaint and should refer the at the restaurant that is the subject of the complainant to the appropriate jurisdiction. complaint. 4.2.5 Collection and testing of clinical • All jurisdictions should have a process specimens and food samples related to to ensure that complaints outside that group illness. PHL activities are essential for AND OUTBREAK DETECTION jurisdiction are forwarded to the proper determining etiology, linking separate events authority. This process includes forwarding during the investigation, and monitoring the complaints between local health agencies, efficacy of control measures (Chapters 5 and 6). FOODBORNE ILLNESS SURVEILLANCE FOODBORNE ILLNESS SURVEILLANCE Box 4.2. Considerations for Investigating a Commercial Food Establishment
In the following situations, investigation of a named commercial food establishment might be warranted: • The confirmed diagnosis and/or clinical symptoms are consistent with the foods eaten and the timing of illness onset (e.g., a person in whom salmonellosis is diagnosed reports eating incompletely cooked eggs 2 days before becoming ill). • The complainant observed specific food-preparation or serving procedures likely to lead to a food safety problem at the establishment. • Two or more persons with a similar illness or diagnosis implicate a food, meal, or establishment and have no other shared food history or evident source of exposure. Regular review of individual complaints is critical to recognizing that multiple persons have a similar illness or diagnosis and share a common exposure. Clues that a follow-up investigation of a food establishment is unlikely to be productive include • Confirmed diagnoses and/or clinical symptoms that are not consistent with the foods eaten at the establishment and/or the onset of illness (e.g., bloody diarrhea associated with a well-cooked hamburger eaten the night before illness onset). • Signs and symptoms (or confirmed diagnoses) among affected persons that suggest they might not have the same illness. • Ill persons who are not able to provide adequate information for investigation, including date and time of illness onset, symptoms, or complete food histories. 2020 | Guidelines for Foodborne Disease Outbreak Response 81
4.2 Complaint Systems
• Because of public health laboratory testing, Primer for Physicians and Other Health links may be seen across jurisdictional Care Professionals (7), and 2017 Infectious boundaries and beyond; even national Diseases Society of America Clinical outbreaks may then be detected. Practice Guidelines for the Diagnosis and For instance, an outbreak associated with Management of Infectious Diarrhea (8). a particular restaurant may come to the • If the presumed exposure involves food at a attention of authorities solely on the basis catered event, collect and store food from the of a report by a customer who observed implicated event, if feasible. illnesses among multiple fellow patrons. • Conduct all sampling using legally defensible Laboratory testing and identification of procedures (e.g., chain-of-custody) and using
Salmonella Typhimurium can result in protocols as guided by the laboratory that 4 refinement of the case definition used in
will conduct the analysis. Samples should AND OUTBREAK DETECTION FOODBORNE ILLNESS SURVEILLANCE this investigation, in additional testing be analyzed within 48 hours after receipt; and restrictions for workers found to be however, generally test the food only after carriers, or in connecting this outbreak epidemiologic implication or identification with other outbreaks (concurrent or of specific food-safety problems through historic) from a contaminated commodity. an environmental health assessment. If the • Obtain clinical specimens from at least five epidemiologic investigation is ongoing and a members of the ill group. Collect specimens specific food item has not been implicated or as soon as possible after illness onset, ideally is not suspected yet, food should be stored. during active illness. For certain etiologies, Consideration include the following: clinical specimens need to be collected while • Storage under refrigeration can be longer the patient is still ill (bacterial intoxications); than 48 hours, if necessary, but the length for many etiologies (norovirus, bacterial of the storage period is food-dependent. pathogens) it may be possible to detect Because certain bacteria (e.g., Campylobacter pathogens in specimens collected days after jejuni) die when frozen, affecting laboratory illness recovery. Clinical specimens should results, immediate examination of samples be tested as soon as possible- some test types without freezing is encouraged. such as syndromic panels (commercially available tests that simultaneously tests Perishable foods should be frozen (–40⁰C for common bacterial, viral, and parasitic to –80⁰C). pathogens) require testing within 4 days of Food samples that are frozen when specimen collection for the results to be valid. collected should remain frozen until Because complaint systems are the examined. primary tool for detecting outbreaks Food samples can be collected as part of caused by pathogens not under the process of removing suspected food surveillance, the clinical presentation from service. and epidemiologic data should direct the testing priorities. If food testing is determined to be necessary—for example, if a food has been A number of references are available epidemiologically implicated—official reference to help ascertain the etiology of an testing methods must be used at a minimum outbreak, e.g., CIFOR’s Outbreak of for regulated products (e.g., pasteurized eggs or Undetermined Etiology agent tables commercially distributed beef). and interactive tool (6), Diagnosis and Management of Foodborne Illnesses, A 82 Council to Improve Foodborne Outbreak Response
4.2 Complaint Systems
Note: Food testing has inherent limitations agent in an outbreak of gastroenteritis at an because most testing is agent-specific, event [10], and atypical enteropathogenic E. and demonstration of an agent in food coli at a restaurant (11). In one study, consumer is not always possible or necessary before complaint surveillance alone led to detection implementation of public health action. of 79% of confirmed foodborne outbreaks, Detection of microbes or toxins in food is most including most norovirus outbreaks (12). important for outbreaks involving preformed • For event-related complaints, food items eaten toxins, such as enterotoxins of Staphylococcus and other exposures are easily determined aureus or Bacillus cereus, where detection because items consumed at the event can of toxin or toxin-producing organisms in be identified by menus or other means and human specimens frequently is problematic. specifically included in the interview. 4 In addition, organisms such as S. aureus and Clostridium perfringens, which are commonly • Complaint surveillance systems are found in the human intestinal tract, can inherently faster than pathogen-specific confound interpretation of culture results. surveillance because the chain of events related to laboratory testing and reporting is Furthermore, food-testing results are often not required. Exposure information gained difficult to interpret. Samples collected through patient interviews has the potential during an investigation might not represent for being high quality because patient recall food ingested when the outbreak occurred. is highest close to the exposure event. Subsequent handling or processing of food • Because of the relatively limited number might result in the death of microorganisms, of exposures to consider, investigations of multiplication of microorganisms originally event-related notifications can be pivotal AND OUTBREAK DETECTION present in low levels, or introduction of new to solving widespread outbreaks detected contaminants. If the food is not uniformly through pathogen-specific surveillance. For contaminated, the sample collected might miss example, a norovirus outbreak associated FOODBORNE ILLNESS SURVEILLANCE FOODBORNE ILLNESS SURVEILLANCE the contaminated portion. Finally, because with contaminated imported raspberries food usually is not sterile, microorganisms can used in commercially distributed ice cream be isolated from samples but not be responsible was initially identified from complaints for the illness under investigation. Thus, food as multiple independent outbreaks (13). testing should not be routinely undertaken Complaint systems are key in identifying but should instead be based on meaningful intentional contamination events that associations identified through data analysis would not be detected in pathogen-specific of interviews with suspected case-patients or surveillance, for example, an outbreak of during environmental health assessments at the methomyl poisoning caused by intentionally implicated food-service establishment. contaminated salsa at a restaurant (14).
4.2.6 A key strength of complaint systems 4.2.7 The value of single complaints of is their ability to detect outbreaks from possible cases of foodborne disease in any cause, known or unknown. Thus, the detecting outbreaks is limited by a lack of complaint system is one of the best methods exposure information to link to any other for detecting nonreportable pathogens and cases and by the lack of specific agent or new or reemerging agents. Recent examples disease information to exclude unrelated include recognition of sapovirus as a significant cases. The illness reported by individuals agent in norovirus-like outbreaks [9], might or might not be foodborne, and illness identification of Arcobacter butzleri as the likely presentation might or might not be typical. 2020 | Guidelines for Foodborne Disease Outbreak Response 83
4.2 Complaint Systems
• Without a detailed food history (either from between agencies that receive illness the initial report or follow-up interview), complaints, epidemiology staff, and surveillance of independent complaints is laboratory staff. Always keep contact sensitive only for short incubation (generally information current. Because complaints chemical- or toxin-mediated) illness or illness might be made to multiple agencies, having with unique symptoms because most people a robust method of sharing information is associate illness with the last meal eaten important. If possible, set up a database before onset of symptoms, they are likely that public health agencies can access and to be correct only for exposures with short review. Information-sharing is particularly incubation times. This is not a limitation if important in adjacent jurisdictions. full interviews are conducted.
• Check complaint information against 4 • Notification of illness in groups generally national databases, such as the USDA- is less sensitive to widespread low-level FSIS Consumer Complaint Monitoring AND OUTBREAK DETECTION FOODBORNE ILLNESS SURVEILLANCE contamination events than is pathogen- System (CCMS) (15). Consumers can report specific surveillance because recognition of a complaints to CCMS by contacting the person–place–time connection among case- USDA-FSIS Meat and Poultry Hotline patients by a healthcare provider or member (1-888-MPHotline [1-888-674-6854]) or of the community is required. using the USDA-FSIS online complaint • These limitations can be minimized by reporting system, the Electronic Consumer Complaint Form (https://foodcomplaint.fsis. Collecting a food history for the 3 days usda.gov/eccf). before illness onset to detect outbreaks caused by etiologic agents with longer 4.2.9 To increase surveillance sensitivity, incubations than bacterial toxins. remove barriers to reporting by making Looking for commonalities between the the reporting process as simple as complete food histories for all complaints possible for the public. For example, provide with case-patient interviews from one 24/7 toll-free telephone number or an pathogen-specific surveillance. online reporting form. Such systems enable callers to leave information that public health Promptly forwarding all complaint to the staff can check later. jurisdictions of establishments mentioned in the food histories for prompt follow-up Promote reporting by routine press releases and/or gathering of additional pertinent that educate the public about food safety, and information. advertise the contact phone number or website for reports of illness. Use a telephone number 4.2.8 Improve communication and that easily can be remembered or found online. cooperation among agencies that receive Train food managers and workers about the illness complaints. Consumers may submit importance of reporting unusual patterns of complaints to multiple organizations and illness among workers or customers and Food agencies, such as poison control centers, Code requirements for disease reporting (16). agricultural agencies, facility-licensing Communicate the value of such reporting, agencies, grocery stores, and online platforms not just to protect public health, but also to and social media sites. protect food establishments from unfounded • Identify the agencies/organizations in allegations of foodborne illness. the community that are likely to receive complaints. Establish regular communication 84 Council to Improve Foodborne Outbreak Response
4.3 Syndromic Surveillance
The concept of syndromic surveillance was groups evaluate alerts triggered by the developed in the 1990s and expanded after syndromic surveillance system, and interview the 2001 postal system anthrax attacks in an case-patients to determine whether the alert attempt to improve readiness for bioterrorism. represents a true outbreak.
The utility of syndromic surveillance for 4.3.1 Potential strengths of syndromic nonspecific health indicators for foodborne surveillance include the use of nonspecific illness surveillance and outbreak investigation health indicators to identify clusters of is very limited. In theory, the electronic disease before definitive diagnosis and collection of such indicators could permit reporting. rapid detection of major trends, including • Syndromic surveillance may be able to 4 outbreaks. In practice, the right mix of detect large undiagnosed events, such as an sensitivity and specificity has proven difficult increase in gastrointestinal illness among to find, and the utility of such systems persons of all ages consistent with norovirus might be marginal. Surveillance for highly or an increase in diarrheal illness among specific syndromes, such as hemolytic uremic young children consistent with rotavirus, and syndrome or botulism, is a critical public it may be helpful for monitoring health status health function. after a natural disaster, if other surveillance • Some groups (e.g., public health agencies, systems are temporarily unavailable. academic researchers, nongovernment organizations) monitor social media 4.3.2 The lack of specificity for most to identify potential outbreaks. The syndromic surveillance indicators in the effectiveness of the use of social media tools area of foodborne disease is a limitation AND OUTBREAK DETECTION to identify outbreaks is still being evaluated that makes for an unfavorable signal-to- but may be useful to enhance traditional noise ratio, meaning that only the largest complaint systems. events would be detected, and many
FOODBORNE ILLNESS SURVEILLANCE FOODBORNE ILLNESS SURVEILLANCE false-positive signals would be expected. • In theory, syndromic surveillance can be used as a tool to identify cases during an • Responding to false-positive signals outbreak of an emerging or rare pathogen substantially drains an agency’s resources. before laboratory testing protocols have been • Syndromic surveillance cannot replace put into place or results have been received. routine surveillance. • Syndromic surveillance can help identify The ultimate measure of success for any general enteric disease trends in a surveillance system is outbreaks detected. community (e.g., norovirus activity levels) Because the usefulness of syndromic to craft targeted prevention messaging surveillance for detecting foodborne disease (e.g., remind food-service establishments to events is limited, additional investment would exclude ill food-service employees). compete for resources with under-resourced Syndromic surveillance typically relies on standard surveillance systems; therefore, automated extraction of health information, it should be used only under very special such as school and work absenteeism, posts or circumstances when routine surveillance is complaints on social media sites, emergency not possible. department chief complaint, lab test orders, or hospital discharge codes (ICD-10). Epidemiology or emergency preparedness 2020 | Guidelines for Foodborne Disease Outbreak Response 85
References
1 Centers for Disease Control and Prevention. Culture- 10 Lappi V, Archer JR, Cebelinski E, Leano F, Besser independent diagnostic tests. https://www.cdc.gov/ JM, Klos RF, et al. An outbreak of foodborne illness foodsafety/challenges/cidt.html among attendees of a wedding reception in Wisconsin 2 Association of Public Health Laboratories. Submission likely caused by Arcobacter butzleri. Foodborne of enteric pathogens from positive culture-independent Pathog Dis. 2013;10:250–5. diagnostic test specimens to public health. Interim 11 Hedberg CW, Savarino SJ, Besser JM, Paulus guidelines. https://www.aphl.org/AboutAPHL/ CJ, Thelen VM, Myers LJ, et al. An outbreak of publications/Documents/FS-Enteric_Pathogens_ foodborne illness caused by Escherichia coli O39:NM, Guidelines_0216.pdf an agent not fitting into the existing scheme for 3 Besser JM, Carleton HA, Trees E, Stroika SG, classifying diarrheogenic E. coli. J Infect Dis. Hise K, Wise M, et al. Interpretation of whole- 1997;176:1625–8. genome sequencing for enteric disease surveillance 12 Li J, Smith K, Kaehler D, Everstine K, Rounds J, and outbreak investigation. Foodborne Pathog Dis. Hedberg C. Evaluation of a statewide foodborne 4
2019;16:504–12. illness complaint surveillance system, Minnesota, AND OUTBREAK DETECTION FOODBORNE ILLNESS SURVEILLANCE 4 Chai SJ, Gu W, O’Connor KA, Richardson LC, 2000 through 2006. J Food Prot. 2010;73:2059–64. Tauxe RV. Incubation periods of enteric illnesses 13 Saupe A, Sorensen A, Rounds JM, Hedeen N, in foodborne outbreaks, United States, 1998-2013. Hooker C, Bagstad EH, et al. Multijurisdictional Epidemiol Infect. 2019 Oct 7;147:e285. doi: 10.1017/ norovirus outbreak associated with commercially S0950268819001651. distributed ice cream, Minnesota, 2016. 2017 CSTE 5 National Library of Medicine. Pathogen detection. Annual Conference; 2017 Jun 4–8; Boise, Idaho. https://www.ncbi.nlm.nih.gov/pathogens https://cste.confex.com/cste/2017/webprogram/ Paper8321.html 6 CIFOR. CIFOR OUE guidelines. http://cifor.us/ clearinghouse/cifor-oue-guidelines 14 Buchholz U, Mermin J, Rios R, Casagrande TL, Galey F, Lee M, et al. An outbreak of food-borne 7 American Medical Association; American Nurses illness associated with methomyl-contaminated salt. Association-American Nurses Foundation; Centers JAMA. 2002;288:604–10. for Disease Control and Prevention; Center for Food Safety and Applied Nutrition, Food and Drug 15 U.S. Department of Agriculture. Food Safety Administration; Food Safety and Inspection Service, Inspection Service. FSIS Directive 5610.1 Rev. 1 U.S. Department of Agriculture. Diagnosis and “Consumer Complaint Monitoring System” (June 29, management of foodborne illnesses: a primer for 2018). https://www.fsis.usda.gov/wps/wcm/connect/ physicians and other health care professionals. MMWR ea2bca70-1099-4857-b220-4e7fcb4a7c5d/5610.1.pdf Recomm Rep. 2004;53(RR-4):1–33. ?MOD=AJPERES] 8 Shane AL, Mody RK, Crump JA, Tarr PI, Steiner TS, 16 Food and Drug Administration. Food Code Kotloff K, et al. 2017 Infectious Diseases Society of 1-201.10(B) (2017). https://www.fda.gov/food/ America clinical practice guidelines for the diagnosis guidanceregulation/retailfoodprotection/foodcode/ and management of infectious diarrhea. Clin Infect default.htm Dis. 2017;65:e45–e80. 9 Blanton LH, Adams SM, Beard RS, Wei G, Bulens SN, Widdowson MA, et al. Molecular and epidemiologic trends of caliciviruses associated with outbreaks of acute gastroenteritis in the United States, 2000–2004. J Infect Dis. 2006;193:413–21.
Resource
Cornell College of Agriculture and Life Sciences. public health. Webinars. https://nyfoodsafety.cals.cornell. New York Integrated Food Safety Center of Excellence. edu/molecular-epidemiology/webinars/ Molecular epidemiology and sequencing approaches in
CHAPTER 5
Cluster and Outbreak Investigation
CHAPTER SUMMARY POINTS
• Outbreak investigations are conducted to rapidly identify the source of contamination and take action to prevent additional illnesses. These investigations require effective and timely integration of three types of data: Epidemiologic data that describe illness distributions and reveal common exposures; Informational traceback and environmental assessment data that identify common contamination points and factors in the distribution chain; and Testing data that identify outbreak-associated strains in implicated foods or in environmental samples linked to the foods. • How a potential outbreak of foodborne illness is initially recognized determines approaches taken to investigate. Complaints identifying multiple illnesses associated with a common event or establishment will lead to an investigation to identify the agent and the mode(s) of transmission. Although most of these investigations will be local, some will be subclusters of larger, multijurisdictional outbreaks. Clusters of cases identified through laboratory-based surveillance at the local or state level will lead to investigations to determine the mode of transmission or source of contamination. Multistate clusters of these cases suggest a commercially distributed food source. Identification of a foodborne pathogen in a commercially distributed food product will lead to a search for illnesses caused by the same organism and an investigation to determine whether the food item was the source of the illness. • A priority for all investigations is to establish the basis for implementing control measures to stop transmission and prevent additional illnesses.
URLs in this chapter are valid as of July 26, 2019. 88 Council to Improve Foodborne Outbreak Response
5.0 Introduction
5.0.1 Outbreak investigations can help surveillance sampling. However, WGS prevent illnesses. This chapter helps may increase the timeline for public health investigators quickly and accurately conduct laboratories to characterize foodborne the various steps of an investigation. pathogens and thus delay the identification of clusters of cases that warrant investigation. These steps are • Culture-independent diagnostic tests (CIDTs) • Detecting a possible outbreak (Chapter 4). used by clinical laboratories provide rapid • Defining and finding cases. test results but require follow-up culture to produce an isolate for WGS. CIDTs might • Generating hypotheses about likely sources. increase the number of cases reported and • Testing hypotheses and evaluating evidence. decrease the timeline from onset of illness • Finding contamination sources. to report but also reduce the proportion of isolates available for WGS and increase • Controlling the outbreak (Chapter 6). the timeline for conducting WGS. CIDTs Because outbreak investigations are dynamic, used by public health agencies may enhance 5 multiple steps can occur simultaneously. additional case finding in an outbreak In addition, as the outbreak investigation investigation by rapidly identifying the agent progresses, steps might need to be repeated. in fecal samples from suspected case-patients. • Enhanced use of new exposure assessment When a potential foodborne illness outbreak methods streamlines epidemiologic is first detected or reported, investigators will investigations to identify common sources not know whether the illness is foodborne, for clusters and determine whether they INVESTIGATION waterborne, or attributable to other causes. constitute foodborne illness outbreaks. Investigators must keep an open mind in the early stages of the investigation to ensure that For purposes of outbreak reporting, the potential causes are not prematurely ruled National Outbreak Reporting System CLUSTER AND OUTBREAK out. Even though these Guidelines focus on (https://www.cdc.gov/nors/downloads/ foodborne illness, many of the investigation guidance.pdf) distinguishes the definitions methods described in this chapter apply to a of an outbreak and a cluster as follows: variety of enteric and other illnesses, regardless • An outbreak is two or more cases of similar of source of contamination. illness associated with a common exposure. 5.0.2 Recent developments in laboratory • A cluster is two or more cases of similar illness and epidemiologic methods impact cluster that are suspected to be associated with a and outbreak investigation methods. common exposure, but investigators are • Whole-genome sequencing (WGS) used unable to identify a shared food, animal, by public health laboratories increases the venue, or experience among ill persons. specificity of pathogen-specific surveillance Outbreak and cluster definitions vary by because case-patients with isolates that have jurisdiction. the same DNA fingerprint are more likely to share a common source (Chapter 4). In Regardless of how clusters are defined for addition, WGS increases confidence in the surveillance purposes, the investigations needed relationships between pathogens isolated from to identify a common exposure include multiple, food/environments and historical samples, interrelated epidemiologic, environmental, and which provides better opportunities to identify laboratory activities (Table 5.1, Figure 5.1). outbreaks through food and environmental 2020 | Guidelines for Foodborne Disease Outbreak Response 89
5.0 Introduction
FOOD TESTING Contact clinical laboratories that might have performed primary testing on case- obtain specimens patients, and or isolates. fecal samples to identify Test agent. samples of implicated Test food items to identify agent. Subtype all isolates as soon possible after receipt. PUBLIC HEALTH AND/OR PUBLIC HEALTH REGULATORY LABORATORY REGULATORY • • • • 5 INVESTIGATION CLUSTER AND OUTBREAK ENVIRONMENTAL HEALTH ENVIRONMENTAL Interview management to determine whether it has that noticed any ill employees or circumstances could cause a foodborne illness. Interview food workers to determine illness. This activity also could be conducted by nursing/healthcare staff. ill or all food workers. Obtain fecal specimens from This activity could also be conducted by nursing/ staff. healthcare samples of implicated and Obtain and store suspected food items and ingredients. Determine whether setting or food item suggests a likely pathogen. • • • • • EPIDEMIOLOGY Contact healthcare providers of case- providers Contact healthcare patients who have sought medical attention. Interview case-patients to characterize symptoms, incubation period, and duration of illness. case- Obtain fecal specimens from patients. Determine whether symptoms, incubation period, or duration of illness suggest a likely pathogen. Establish case definition based on of confirmed diagnosis or clinical profile cases. If outbreak is identified by pathogen-specific surveillance: Agent known. If outbreak • • • • • If outbreak is associated with event or establishment: If outbreak Objectives and Investigation Activities that Can Be Conducted During Epidemiologic, Environmental Health, and Objectives and Investigation Activities that Can Be Conducted During Epidemiologic, Environmental Public Health Laboratory Investigations of Foodborne Illness Outbreaks*
Table 5.1. Table OBJECTIVE Identify etiologic agent. 90 Council to Improve Foodborne Outbreak Response
5.0 Introduction FOOD TESTING Contact clinical laboratories to identify additional fecal specimens being tested. Contact clinical laboratories to identify additional fecal specimens being tested. and Prioritize referral subtyping of outbreak pathogen. PUBLIC HEALTH AND/OR PUBLIC HEALTH • • • REGULATORY LABORATORY REGULATORY 5 ENVIRONMENTAL HEALTH ENVIRONMENTAL INVESTIGATION Obtain list of reservations for establishment, Obtain list of reservations for takeout receipts receipts, card credit at inventory of foods ordered orders, establishment, or guest lists for events. Where possible, obtain information electronically. Review foodborne illness complaints to identify undiagnosed cases that could be linked to outbreak. or other stores, grocery Contact restaurants, points of final service visited by multiple case-patients to identify employee illnesses or patrons. foodborne illness complaints from • • • CLUSTER AND OUTBREAK EPIDEMIOLOGY Obtain from event organizer a list of persons event organizer Obtain from if possible, list of persons attending event or, the establishment during outbreak patronizing period. Interview persons who attended event or patronized establishment to determine attack rates by time. to identify additional providers Contact healthcare whose illnesses meet persons seeking medical care the case definition. recently review reportable, If identified agent is to cases to identify possible exposures reported event or establishment. to of possible outbreak providers Alert healthcare identify additional persons seeking medical care, and medical charts at laboratory reports and review hospitals or physicians’ offices to identify possible cases. Ask case-patients if they know of others who are similarly ill. take additional of outbreak, Depending on nature employee steps as warranted.For example, review death certificates, survey or school absences, review ask members of the or directly population affected, public to contact the health department if they have the illness under investigation. • • • • • • • If outbreak identified by pathogen-specific surveillance: If outbreak If outbreak is associated with event or establishment: If outbreak Public Health Laboratory Investigations of Foodborne Illness Outbreaks* Objectives and Investigation Activities that Can Be Conducted During Epidemiologic, Environmental Health, and Objectives and Investigation Activities that Can Be Conducted During Epidemiologic, Environmental
Table 5.1. Table Continued OBJECTIVE Identify persons at risk, and determine size and scope of outbreak. 2020 | Guidelines for Foodborne Disease Outbreak Response 91
5.0 Introduction FOOD TESTING Test implicated food and Test samples to environmental of agent. confirm presence Subtype all isolates as soon as possible after receipt. Conduct applied food-safety to determine ability research of agent to survive or multiply in implicated vehicle and how vehicle might have become contaminated. collected food Store of samples, pending results epidemiologic analyses. implicated food Culture samples to confirm presence of agent. Conduct whole-genome sequencing to further characterize pathogen as necessary for investigation. Conduct applied food-safety to determine ability research of agent to survive or multiply in implicated vehicle and how vehicle might have become contaminated. PUBLIC HEALTH AND/OR PUBLIC HEALTH • • • • • • • REGULATORY LABORATORY REGULATORY 5 INVESTIGATION CLUSTER AND OUTBREAK ENVIRONMENTAL HEALTH ENVIRONMENTAL Obtain menu from establishment or event. Obtain menu from Interview food workers to determine food- responsibilities. preparation Reconstruct food flow for implicated meal or food item. Identify contributing factors and antecedents. environmental Obtain samples of implicated food. food samples from Obtain environmental contact surfaces or possible environmental reservoirs. or other stores, grocery Contact restaurants, locations identified by multiple case-patients to verify menu choices, identify ingredients, for and identify distributors and/or source(s) and/or food items of interest. ingredients Obtain samples of suspected food items. authority to regulatory with appropriate Work collected and that food samples are ensure chain of custody. maintained with appropriate authority to take This will help the regulatory action. regulatory appropriate Conduct an informational traceback to determine whether a suspected food vehicle multiple case-patientss has a distribution from or other point in common. • • • • • • • • • EPIDEMIOLOGY Determine appropriate analytical study approach. Determine appropriate or Interview identified case-patients and controls well meal companions about all common exposure sources. of association for specific Calculate measures to study design (i.e., odds appropriate exposures, study or attack rates and ratios for case–control risks for cohort study). relative Interview case-patients as soon possible with history questionnaire detailed exposure standardized to identify possible common exposures. Establish case definition on the basis of characteristics of agent that led to detection outbreak. Characterize cases by person, place, and time, evaluate this descriptive epidemiology to identify patterns possibly associated with particular food items or diets. history questionnaire detailed exposure Compare against known or estimated background frequencies rates, to identify suspected food item. exposure or nonoutbreak- Interview nonill community controls associated ill persons to obtain detailed exposure information to be used in a case-comparison analysis of exposures. • • • • • • • • If outbreak identified by pathogen-specific surveillance: If outbreak If outbreak is associated with event or establishment: If outbreak OBJECTIVE Identify mode of transmission and vehicle. 92 Council to Improve Foodborne Outbreak Response
5.0 Introduction FOOD TESTING Evaluate results of all outbreak- Evaluate results subtyping associated culture to highlight possible relations clinical, among isolates from food, and environmental samples. Conduct applied food-safety to determine how research vehicle might have become contaminated. PUBLIC HEALTH AND/OR PUBLIC HEALTH REGULATORY LABORATORY REGULATORY • • 5 INVESTIGATION ENVIRONMENTAL HEALTH ENVIRONMENTAL If specific food item or ingredient is implicated, If specific food item or ingredient conduct formaltraceback. regulatory Interview food workers to determine food- responsibilities. preparation Reconstruct food flow for implicated meal or item. Evaluate food flow for implicated meal or item to identify contamination event at point of or service. preparation of If no contamination event identified, trace source of implicated food item back through ingredients a contamination event distribution to point where if no contamination events can be identified or, of can be identified during distribution, to source production. CLUSTER AND OUTBREAK • • • • • EPIDEMIOLOGY Obtain shopper card information to Obtain shopper card and purchases identify and verify grocery possibly determinerates of background of item. purchase code Document brand names and product food items. information for prepackaged information Analyze exposure comparing (e.g., comparison groups cases to relevant or cases not associated nonill controls to implicate food item or with outbreak) source. nonfood exposure Combine descriptive and analytical to develop a model epidemiology results for the outbreak. • • • • If outbreak identified by pathogen-specific surveillance: If outbreak is associated with event or establishment: If outbreak Public Health Laboratory Investigations of Foodborne Illness Outbreaks* Objectives and Investigation Activities that Can Be Conducted During Epidemiologic, Environmental Health, and Objectives and Investigation Activities that Can Be Conducted During Epidemiologic, Environmental
Table 5.1. Table Continued OBJECTIVE Identify mode of transmission and vehicle. Identify of source contamination. 2020 | Guidelines for Foodborne Disease Outbreak Response 93
5.0 Introduction Evaluate results to highlight Evaluate results among possible relations and food, clinical, from isolates samples. environmental Conduct applied food-safety to examine likely research of contamination. sources with appropriate Work authority to regulatory that food samples are ensure collected and maintained with chain of custody. appropriate This will help the regulatory authority to take appropriate action. regulatory Summarize information about clinical, from testing results food, and environmental samples. Summarize information about clinical, from testing results food, and environmental samples. statistics background Provide on pathogen prevalence. • • • • • • 5 INVESTIGATION CLUSTER AND OUTBREAK Reconstruct food flow for implicated item. Interview food workers to determine food- and practices before responsibilities preparation exposure. Obtain samples of implicated food or ingredients. food contact samples from Obtain environmental reservoirs. surfaces or potential environmental Trace source of implicated food item or ingredients of implicated food item or ingredients source Trace a contamination distribution to point where through of production event can be identified or to source if no contamination events can be identified during distribution. assessment of likely source Conduct environmental of contamination, including assessment, given of environmental Evaluate results results of epidemiologic identification of agent and investigation, to identify factors most likely have and their environmental contributed to outbreak antecedents. assessment, given of environmental Evaluate results results of epidemiologic identification of agent and investigation, to identify contributing factors and antecedents. • • • • Combine descriptive and analytical to develop a model epidemiology results for outbreak. Summarize information to identify confirmed or suspected agent. Summarize information to identify confirmed or suspected food vehicle. Summarize information to identify confirmed or suspected food vehicle. If outbreak is identified by pathogen-specific surveillance: If outbreak • • • • If outbreak is identified by pathogen-specific surveillance: If outbreak If outbreak is associated with event or establishment: If outbreak Identify of source contamination. Identify contributing factors and antecedents causes) (root 94 Council to Improve Foodborne Outbreak Response
5.0 Introduction - FOOD TESTING Assess status of completed and pending testing to identify gaps that suggest a potential for ongoing transmission. Assess status of completed and pending testing to identify gaps that may suggest a potential for ongoing transmission. PUBLIC HEALTH AND/OR PUBLIC HEALTH REGULATORY LABORATORY REGULATORY • • 5 INVESTIGATION ENVIRONMENTAL HEALTH ENVIRONMENTAL CLUSTER AND OUTBREAK Verify that all food workers who pose a risk for transmission have Verify as appropriate. been excluded or restricted, that potentially contaminated foods have been properly Verify disposed of. that food contact surfaces and potential environmental Verify have been adequately cleaned and sanitized. reservoirs practices. in safe food-preparation staff Train with processes and food-preparation Modify food-production controls. preventive appropriate Modify menu. Implement control measures to prevent further exposures: to prevent measures Implement control review additional control cannot be verified, If any of these measures alert public or close appears likely, or if further exposure measures, premises. that food workers who might have been infected during outbreak Verify and who pose a risk for transmission have been excluded or restricted, as appropriate. from that potentially contaminated foods have been removed Verify distribution. practices. on safe food-preparation staff Train by processes and food-preparation Modify food-production controls. preventive implementing appropriate Modify menu. • • • • • • •
EPIDEMIOLOGY On the basis of agent, incubation period, and likelihood of secondary epidemic create spread, curve, and evaluate the to course of the outbreak determine whether additional cases may still be occurring. appears If outbreak to be ongoing, review measures possible control in collaboration with health environmental specialists. and evaluate epidemic Create curve to determine whether additional cases might still be occurring. appears to If outbreak be ongoing, continue surveillance, and review potential abatement procedures. If outbreak is identified by pathogen-specific surveillance: If outbreak • • • • If outbreak is associated with event or establishment: If outbreak Public Health Laboratory Investigations of Foodborne Illness Outbreaks* Objectives and Investigation Activities that Can Be Conducted During Epidemiologic, Environmental Health, and Objectives and Investigation Activities that Can Be Conducted During Epidemiologic, Environmental
The table format highlights the major objectives of the investigation to help ensure coordination among epidemiologists, environmental health specialists, and laboratorians among epidemiologists, environmental The table formatcoordination highlights the major objectives of investigation to help ensure The actual responsi to a particular discipline within each table is not intended be prescriptive. in meeting each objective. The assignment of investigation responsibilities ction responsible for the investigation, roles defined in the outbreak investigation and control team, and resources. team, and investigation and control defined in the outbreak for the investigation, roles bilities for an individual vary by the practices of jurisdi ction responsible Table 5.1. Table Continued OBJECTIVE Determine potential for ongoing transmission and need for abatement procedures. * 2020 | Guidelines for Foodborne Disease Outbreak Response 95
5.0 Introduction
Figure 5.1. Steps in a Foodborne Illness Outbreak Investigation
5 INVESTIGATION CLUSTER AND OUTBREAK 96 Council to Improve Foodborne Outbreak Response
5.1 Outbreak Investigation Initiation
5.1.1 Alert outbreak investigation and as soon as possible for the additional resources control team leaders as soon as a possible and expertise required to respond to it outbreak is identified. Outbreaks are detected (Chapter 3). in several principle ways (Chapter 4). However, a common initial approach is to review 5.1.3 Assemble and brief the outbreak descriptive features of the outbreak setting and investigation and control team. Open relevant background information about the communication between investigation etiologic agent, establishment, or event: members to plan, conduct, and evaluate outbreak investigation activities is critical to the • Most local investigations require success of the investigation. coordination between epidemiologists, environmental health specialists, and public • Investigation and control team leaders health laboratorians within the jurisdiction should assess the availability of staff to of the cases, event, or establishment. conduct the investigation. In particular, the • Multistate clusters also require communica- team leader should ensure the presence of tion and coordination of activities between adequate staffing to interview case-patients 5 local, state, and federal agencies to rapidly within 24–48 hours. If sufficient staff are investigate a suspected vehicle (Chapter 7). not available, request external assistance to conduct interviews. 5.1.2 Assess the priority of the outbreak • Outbreak investigation and control staff investigation. Although any outbreak might should be briefed on the outbreak, and warrant investigation, give highest priority for their individual roles in the investigation. investigation to outbreaks that
INVESTIGATION Ensure that all members of the investigation • Have a high public health impact: team—epidemiologists, laboratorians, and environmental health specialists—are Cause severe or life-threatening illness, familiar with and follow relevant state and
CLUSTER AND OUTBREAK such as infection with Escherichia coli federal laws and data handling practices. O157:H7, Listeria monocytogenes, or botulism; • For outbreaks involving multiple jurisdictions, the outbreak investigation and control team Affect populations at high risk for should include members from all agencies complications of the illness (e.g., infants, participating in the investigation (Chapter 7). elderly persons, immunocompromised persons); or 5.1.4 Ensure that leadership of the Affect a large number of persons. investigation reflects the focus of investigation activities, which may change • Appear to be ongoing: over time. During an investigation, the focus May be associated with food-service of activities may shift among the following: establishment in which ill food workers provide a continuing source of infection. • Laboratory studies to identify an agent, including microbiologic studies and applied May be associated with a commercially food-safety research. distributed food product that is still being consumed. • Epidemiologic studies to identify transmission routes, exposure sources, or If the scale or complexity of an outbreak food vehicles and risk factors for illness. investigation is likely to overwhelm agency • Regulatory investigations of food-production resources, the agency should request assistance sources and distribution chains to identify 2020 | Guidelines for Foodborne Disease Outbreak Response 97
5.1 Outbreak Investigation Initiation
where, during production or distribution • Complaints identifying multiple illnesses of the food, contamination occurred and associated with a common event or facilitate recall of food items. establishment will lead to an investigation • Environmental assessments of food pro- to identify the agent and the mode(s) of duction, processing, and service facilities to transmission. Most of these investigations identify routes of contamination, contributing will be local and require coordination factors, and environmental antecedents; between epidemiologists, environmental health specialists, and public health • Communication of investigation findings to laboratorians within the jurisdiction of the public and the food industry to support the event or establishment. Case-patients control and prevention measures. need to be rapidly interviewed to confirm illness and exposure details that may suggest 5.1.5 Coordinate activities and set up a likely etiology and potential source of good lines of communication between exposure. Environmental health specialists, individuals and agencies involved in the guided by descriptive epidemiology, need investigation (Chapter 3, Chapter 7). to assess food-handling practices and food 5
Investigations are rarely linear (Figure 5.1). worker health and hygiene habits at the INVESTIGATION CLUSTER AND OUTBREAK Although the steps for investigating outbreaks establishment. Public health laboratories follow a logical process—from determining need to test clinical specimens to confirm whether an outbreak is occurring to the etiology of the outbreak based on identifying and controlling the source—most the description of signs, symptoms, and investigations feature multiple concurrent incubation periods (CIFOR Outbreaks of steps. Maintaining close communication and Undetermined Etiology Guidelines [1]). If coordination among members of the outbreak the source of contamination was determined investigation team is the best way to ensure to be upstream from the establishment, that concurrent activities do not interfere with the outbreak could involve multiple each other and important investigation steps locations and require a multijurisdictional are not forgotten. investigation (Chapter 7). • Clusters of cases identified through 5.1.6 Establish goals and objectives for laboratory-based surveillance at the local the investigation. The primary goal for most or state level will lead to investigations to investigations is to obtain enough information determine the mode of transmission or to implement specific interventions to stop source of contamination. Case-patients need the outbreak. The results of the investigation to be rapidly interviewed with a thorough also should provide information to prevent a exposure assessment questionnaire to similar outbreak from occurring in the future. identify potentially common exposures or Secondary goals are to increase knowledge of likely routes of transmission. Environmental the epidemiology and control of foodborne health specialists and food regulators need to illnesses. Unanswered questions about the be prepared to help investigate subclusters etiologic agent, the mode of transmission, or associated with food establishments and to contributing factors should be identified and initiate product tracing for suspected food included in the investigation to add to the exposures. Public health laboratories need to public health knowledge base. rapidly confirm additional cases, and food- Objectives for meeting these goals vary by type regulatory laboratories need to prepare to of outbreak. rapidly test suspected food products. 98 Council to Improve Foodborne Outbreak Response
5.1 Outbreak Investigation Initiation
• Multistate clusters of cases suggest a determine whether the food item was the commercially distributed food source source of the illness. This type of outbreak (Chapter 7). Product tracing may be presentation will most likely increase with needed for successful exposure assessment. the use of WGS to link isolates from food or Communication and coordination of environmental samples with cases identified activities between local, state, and federal through pathogen-specific surveillance. agencies must be established at the onset of In all instances, investigating the possible the investigation. link between contaminated food product • Identification of a foodborne pathogen in and illnesses requires multijurisdictional a commercially distributed food product investigation to assess the likelihood the will lead to a search for illnesses caused by cases are attributable to the suspected food the same organism and an investigation to exposure.
5.2 Define and Find Cases 5
5.2.1 Developing case definitions. Initially, • During the early stages of the case definitions reflect the cluster recognition investigation, case definitions should be methods. made specific to increase the likelihood that the detected cases share a common • A cluster of illnesses linked to foodborne exposure. Including unrelated cases in an illness complaints most likely will be defined outbreak investigation makes recognizing INVESTIGATION by similar features of the illness and by a common exposure more difficult and common suspected source of exposure, such dilutes observed measures of association in as time, place, or person. As case-patients are analytic studies. For example, in an outbreak interviewed, a distinctive clinical profile may CLUSTER AND OUTBREAK of salmonellosis, case-patients may share emerge that suggests an etiology. If testing common symptoms of diarrhea and fever of clinical specimens confirms an agent, and all their illnesses might be caused by the features of that agent can be used to isolates with the same serotype that have establish a clinical case definition. a distinctive PFGE pattern and are closely • Clusters of cases identified by pathogen- related by WGS. Each of these additional specific surveillance are usually defined points of identity increases the likelihood by common phenotypic or molecular that the cases are related and the source may characteristics (serotype, pulsed-field gel be identified. electrophoresis [PFGE] pattern, WGS), • After a common source has been identified, time frame when the cases occurred, and changing the case definition might be geographic distribution of the cases. CIDTs necessary or desirable to better assess the are a challenge to this approach. Although magnitude of the outbreak. A change might the initial CIDT-positive result may be be needed when additional pathogens, or available within a few days after onset of strains of a pathogen, are linked to the same illness, the need to perform culture and then source. Although outbreaks are detected subtype the isolate means that some cases through monoclonal surveillance for highly will not be subtyped, and the timeline will defined clusters, many food-contamination be longer for those that are cultured and events are polyclonal, i.e., involve multiple subtyped. strains of pathogenic bacteria. The true 2020 | Guidelines for Foodborne Disease Outbreak Response 99
5.2 Define and Find Cases
nature of these events is usually not 5.2.3 Supplement case-finding activities. discovered until late in the investigation. Ask local clinical and laboratory professionals In addition, after a common source has to report cases as soon as they suspect the been identified, accounting for illnesses that diagnosis, alert health officials in surrounding occurred after exposure to the source that areas to watch for illnesses that might be were not confirmed but had similar clinical related, and survey groups that may have characteristics to the confirmed cases can been exposed. help provide a better estimate of the size, scope, and public health impact of the 5.2.4 Plot Cases on an Epidemic Curve to outbreak. Track Illnesses Over Time. The epidemic curve (epi curve) shows progression of an 5.2.2 Reviewing current surveillance active outbreak over time. The horizontal axis systems for illnesses that meet the case (x-axis) is the date a person became ill (date of definition. Once a case definition has been onset). The vertical axis (y-axis) is the number established, investigators should search for of persons who became ill on each date. These
more illnesses related to the outbreak. numbers are updated as new data come in 5 and thus are subject to change. The epi curve INVESTIGATION CLUSTER AND OUTBREAK • For clusters of illnesses reported through is complex and incomplete. Several issues are complaints, review complaint logs or important in understanding it: databases to find other complaints that identify exposure to the suspected • An inherent delay exists between the date of event or establishment. Although many illness onset and the date the case is reported complainants focus on their most recent to public health authorities. For example, for exposure, reviewing all exposures in a 3-day Salmonella infections, this delay is typically food history could link unrecognized cases is 2–3 weeks. Therefore, a person who to the outbreak. A 3-day history may not became ill last week is unlikely to have been cover the exposure window for all cases, but reported yet, and a person who became ill 3 it covers the most common foodborne illness weeks ago might just now be reported. (See incubation periods and saves resources. Salmonella Outbreak Investigations: Timeline In addition, if the confirmed etiology of for Reporting Cases [Chapter 4, Figure 4.1].) the complaint-based outbreak is Salmonella, • Some cases are background cases of illness Shiga toxin–producing E. coli, or other that most likely would have occurred even foodborne pathogen for which case-patients without an outbreak; therefore, determining are routinely interviewed, reviewing all exactly which case is the first in an outbreak exposures for case-patients interviewed is difficult. Epidemiologists typically focus on during the likely outbreak period could link the first recognized cluster or group of cases unrecognized cases to the outbreak. rather than on the first case. Because of the • For clusters identified through laboratory- inherent reporting delay, a cluster sometimes based surveillance, review regular is not detected until several weeks after surveillance reports and laboratory people became ill. reports. In addition, for restaurants and • For some cases, date of illness onset is not retailers identified in the relevant exposure known because of the delay between reporting window, review the complaint database to and case-patient interview. Sometimes an identify potential subclusters of cases. interview never occurs. If the date an ill person brought his or her specimen to the 100 Council to Improve Foodborne Outbreak Response
5.2 Define and Find Cases
laboratory for testing is known, date of illness • Because of the reporting delay, determining onset can be estimated as 3 days before that. the end of an outbreak can be difficult. The • Determining when cases start to decline can curve for the most recent 3 weeks always be difficult because of the reporting delay makes the outbreak appear to be ending, but becomes clearer as time passes. even it is ongoing. The full shape of the curve is clear only after the outbreak ends.
5.3 Generate Hypotheses about Likely Sources
To narrow the focus of an investigation Questionnaire (NHGQ) to collect information and most effectively use time and resources, on a broad range of food and nonfood exposures investigators should begin to generate (http://cifor.us/downloads/clearinghouse/ hypotheses about potential sources of the NHGQ_v2_OMB0920_0997.pdf). outbreak during the earliest stages of the
5 investigation and refine them as they receive The NHGQ contains a mix of closed- and information. Hypotheses may emerge from open-ended questions designed to elicit common case characteristics, shared exposures, likely exposure sources. However, the or historical information about the agent. The NHGQ cannot capture detailed source process comprises several key steps. information about all possible exposures, and supplemental approaches may be needed. A 5.3.1 Review demographic information, key to identifying the source of an outbreak
INVESTIGATION including age, sex, and geographic and is to collect detailed information on both the temporal distributions of case-patients. food item and its source for as many cases as The Centers for Disease Control and possible as early in the process as possible. Prevention (CDC) developed the System for CLUSTER AND OUTBREAK Enteric Disease Response, Investigation, and When conducting hypothesis-generating Coordination to help organize and visualize interviews, use the following interview cluster-associated data (2). Patterns in the techniques to improve food recall: distributions of these characteristics may • Question case-patients as soon as possible suggest possible sources. On a local level, case after their illnesses are reported. surveillance data should be reviewed with data • Encourage them to remember information from foodborne illness complaints. by asking them to elaborate on where 5.3.2 Review previous exposure sources they ate, with whom they ate, and events linked to the agent. Identify previous vehicles associated with the meals. Ask them to look associated with outbreaks and isolation of at a calendar from the appropriate time the agent from food items or food-production periods to jog their memory. environments. However, avoid focusing only on • Interview persons who prepared meals historic sources because they could miss a new during the period of interest. or previously unknown source. • Ask case-patients whether they keep cash 5.3.3 Use standardized data collection register or credit card receipts, or review forms, and compile data from case-patient online banking or bank statements to interviews. CDC, in collaboration with states, indicate where or what they ate. Purchase developed a National Hypothesis Generating receipts can often be reproduced if the case- patient paid with a credit card. 2020 | Guidelines for Foodborne Disease Outbreak Response 101
5.3 Generate Hypotheses about Likely Sources
• If the case-patient uses a grocery store suspicious exposures are identified during shopper card, ask permission to obtain interviews, the initial case-patients are purchase records for a specified time period. systematically reinterviewed to uniformly assess Some grocery chains readily cooperate with these suspicious exposures. Newly reported these requests; others require additional case-patients also will be asked specifically documentation, which delays investigation. about these exposures (Figure 5.2).
• Use a structured list of the places where On the basis of this information, investigators people might get food to encourage case- can identify possible exposures for further patients to think about possible exposures evaluation by epidemiologic, laboratory, or other than restaurants and grocery stores. environmental studies. These should include The list could include food pantries, farmers the review of specific information about markets, conferences and meetings, caterers, establishments/products of interest: and meal delivery services. • Guest lists for common events reported by 5.3.4 Use a dynamic cluster investigation case-patients. process to generate and develop 5 • Historical information on firms or food items hypotheses. In the dynamic cluster INVESTIGATION CLUSTER AND OUTBREAK investigation model, initial case-patients within of interest. a recognized cluster are interviewed with a • Recipe and ingredient lists for common detailed exposure history questionnaire. As menu items.
Figure 5.2. Dynamic cluster investigation
AddeNoveld SuspiciousExposure Exposuraddede
Hypothesis – generating 1 2 3 4 questionnaire
Suspicious Same exposure or exposure as specific case 1 information identified
In this model, case-patients are interviewed with a detailed hypothesis-generating questionnaire. Specific exposures shared by multiple cases might surface that are suspicious because they involve commodities not commonly eaten, or involve specific brands of a commonly eaten food item. Because the original questionnaire might not have captured these exposures, specific questions should be added to the questionnaire for future use, and to systematically re-interview cases to assess the suspicious sources discovered during the investigation process. 102 Council to Improve Foodborne Outbreak Response
5.3 Generate Hypotheses about Likely Sources
• Shopper card data or reproduced receipts • Once a subcluster is identified, reinterview from credit card purchases to compare previously interviewed case-patients grocery store or online meal purchases and ask specifically about the subcluster establishment. Ask all newly identified In practice, the generation and testing of cluster case-patients specifically about hypotheses is an iterative process, and the the subcluster establishment during their hypothesis is modified as more information first interview. Ask them to check credit/ is obtained. debit card statements to improve recall. Obtain and analyze shopper card records 5.3.5 Investigate subclusters. When for cases linked to common grocery store a group of case-patients within a cluster chains; grocery store receipts also can often identifies exposure to the same individual be reproduced if the purchase was made point of service, such as a restaurant, cafeteria, with a credit card, even for a store without grocery store, or institution, this group of a shopper card program. Pinpointing the cases is termed a subcluster and represents an purchase date and meal date to the extent invaluable opportunity to solve the outbreak feasible is important. (If a receipt or credit 5 because the outbreak vehicle was most likely card statement is not available, record the served or sold by the common establishment. case-patient’s level of confidence about the Thus, subcluster investigations represent a purchase or meal date.) hybrid of hypothesis-generating and hypothesis- testing approaches and are a useful model of • Gather detailed food-consumption data the general approach to outbreak investigations. for subcluster cases. Interview case-patients using the subcluster establishment’s menu INVESTIGATION • Commit all available resources to rapidly or, if an event cohort with a limited discrete and comprehensively investigate such a menu is identified, a more defined menu. subcluster to increase the investigation’s Ask case-patients about additions or likelihood of success. If resources are not
CLUSTER AND OUTBREAK subtractions to the menu item(s) they available to conduct an investigation fully and ordered. rapidly, seek assistance from other agencies. Interview the establishment manager • Ascertain additional cases associated and/or chef to obtain ingredient lists for with subcluster locations. In their initial menu items. interview, ask all newly identified case- patients within a cluster to identify all dining Compile a frequency distribution of locations at which they ate during the ingredients consumed by case-patients. exposure period. Case-patients often do not Include every ingredient consumed by at recall eating at some locations outside the least one case-patient. home when asked open ended questions on • Conduct an analytical study at the initial interview (e.g., “What restaurants did subcluster establishment. Conduct an you eat at?”). Ask all newly identified case- ingredient-specific case–control study. There patients in a cluster specifically about the is no rule as to a minimum number of cases list of dining locations named by previously necessary to initiate such a study, but it is interviewed persons. Ascertain additional reasonable to do so with as few as three cases. subcluster cases by contacting additional patrons of the subcluster establishment (e.g., Identify additional cases and enroll through credit card receipts, online orders, controls by or reservations). . Asking case-patients for meal companions; 2020 | Guidelines for Foodborne Disease Outbreak Response 103
5.3 Generate Hypotheses about Likely Sources
• Obtaining credit card receipts, reservation multiple points of service), trace back lists, takeout orders, and/or lists of workers ingredients implicated in analytic studies or students (if a school cafeteria) for patrons or, if analytic studies cannot be done, who dined at the establishment on the ingredients that case-patients most implicated meal dates. frequently consumed. Do not exclude Ascertain additional cases (and increase food ingredients from an analytic the number of controls) to increase the study based on apparent differences likelihood of meaningful results and your in distributors for ingredients used by confidence in those results. the subcluster establishments because commonalities in the source of food items Make the clinical case definition specific might not occur until farther back in the for the pathogen of interest (e.g., for distribution chain. Salmonella use “fever and diarrhea” or “diarrhea duration >3 days”) to minimize • Link subclusters in multistate outbreak the likelihood that unrelated illness will to look for common distribution links between establishments (possible even if dilute associations. 5 there are too few cases for a case–control Include every plausible ingredient in study). Traceback of individual cases also INVESTIGATION CLUSTER AND OUTBREAK the study. Be systematic—do not focus can provide important information to solely on one or two ingredients case- corroborate subcluster data. patients commonly reported. Some ingredients (e.g., spices, garnishes) may 5.3.6 Maintain open, regular be used in multiple menu items and thus communication between public health could be overlooked. and regulatory partners to discuss new or Trace back suspected vehicle(s). If updated information about the epidemiologic there are multiple subclusters (i.e., investigation and food/establishment findings.
5.4 Test Hypotheses
Much of the work of outbreak investigations on the setting of the outbreak, number of involves developing sound hypotheses cases reported, and public health resources that explain the patterns of illnesses available. In recent years, approaches to using observed. Testing these hypotheses requires these study methods have evolved that have epidemiologic analysis of common exposures, resulted in fewer large community case–control typically combined with informational studies. Instead, investigators now often use traceback and environmental assessment case-aggregation methods with comparisons data that identify common contamination to reference data or, for very specific product points in the distribution chain and testing identification (e.g., brand names and lot data that identify outbreak-associated strains numbers), direct intervention with no analytic in implicated foods or in environmental study whatsoever. samples linked to the foods. • Cohort study. Cohort studies are limited 5.4.1 Analytic studies: characteristics, to outbreaks with defined exposure use, and limitations. Epidemiologic studies settings in which exposed persons can be to analyze the association between illness and identified without respect to illness status, exposures take different forms depending e.g,, a banquet with a defined guest list. 104 Council to Improve Foodborne Outbreak Response
5.4 Test Hypotheses
Interviewing persons without respect to Despite their empirical usefulness, large their illness status enables determination of community-based case–control studies are attack rates to assess the magnitude of the no longer routinely conducted in outbreak outbreak and calculation of relative risks for investigations. Recruiting suitable controls individual exposures. Because many of these because of the changing demographics settings involve a defined menu and guest of telephone use is increasingly difficult. list, developing an online survey to rapidly Thus, they have become too expensive to collect illness and exposure information conduct and can be too slow to produce might be possible. actionable results. • Establishment-specific case–control study. • Case–case comparison studies. Case–case In defined setting outbreaks where it is comparison studies provide many of the more feasible to identify individual cases same benefits as community case–control than groups of exposed persons, conduct studies but are logistically easier to conduct. an establishment-specific case–control study Molecular subtype–specific surveillance (similar to a subcluster study). based on PFGE or WGS makes it possible 5 • Community case–control study. to compare cases caused by an outbreak- Community case–control studies are a staple associated strain with cases caused by of outbreak investigations. Comparing unrelated strains. Because cases caused food exposures among case-patients in an by unrelated strains have many different outbreak with food exposures among healthy sources of exposure, they make an efficient controls has great power to identify foods control group. When persons with sporadic associated with the illnesses. For example, cases are routinely interviewed with detailed INVESTIGATION in a nationwide outbreak of Salmonella food-exposure questionnaires, case–case associated with commercially distributed comparison studies can be conducted. For ice cream, the source was identified based example, in the 2011 outbreak of listeriosis identified by the Colorado Department of CLUSTER AND OUTBREAK on interviews of 15 case-patients and 15 community controls (3). Although results Public Health and Environment, cantaloupe of the case–control study implicated an was implicated by comparing exposures from exposure source within 3 days after initiating reported outbreak-associated case-patients to the case–control study, regulatory testing aggregated exposures of nationally reported to confirm the source of contamination cases collected by CDC’s Listeria Initiative (4). required an additional 10 days. Case–case comparisons produce the Having a stringent case definition is same measures of association as case– important to reduce the likelihood of control studies and are interpreted the including unrelated cases in the study. same way. The increased stringency of Because unrelated cases would not share WGS to discriminate outbreak-associated the same exposure source, they would from unrelated cases makes case–case reduce the apparent odds ratio, and comparisons a desirable alternative to make it difficult to implicate the exposure case–control studies when aggregate case source. WGS subtyping enables stringent exposure data are available. case definitions. Along with specific case • Case series with binomial exposure definitions, having detailed exposure assessments. The use of case series source information is critical. with binomial exposure assessments was pioneered by the late Bill Keene at the Oregon Health Authority, who also 2020 | Guidelines for Foodborne Disease Outbreak Response 105
5.4 Test Hypotheses
developed a simple binomial calculator to of these studies by providing precise case test the significance of differences between definitions. Increasing the specificity of food case and population exposure proportions. exposures will similarly increase the efficiency Like the other analytic study methods, it of the study. However, with WGS, the expected requires that outbreak-associated case- increase in small cluster investigations limits patients to be systematically interviewed the usefulness of any of these study designs using a detailed exposure questionnaire. to produce “significant” results. For clusters However, instead of comparing case involving fewer than five cases, product source exposure histories with community controls tracing and corroborating evidence are needed or unrelated cases, the case exposures are to confirm the source. compared with an expected value based on population survey data. FoodNet’s Atlas of 5.4.2 Product tracing. Tracing the source of Exposures (5) has been the most commonly food items or ingredients through distribution used source of population exposure data. to source of production can be critical to However, changing food consumption identifying epidemiologic links among cases or
patterns limit the usefulness of 2006 Atlas ruling them out. For nonbranded commodities, 5 such as produce items, the identification of
data for some exposures. A survey to collect INVESTIGATION CLUSTER AND OUTBREAK updated population exposure data was a common point in multiple distribution conducted in December 2017 through July pathways that provided a suspected product 2019. Identifying current, local population to case-patients may identify the point where exposure data is preferred. The Oregon the food(s) became contaminated (Figure 5.3). Health Authority is compiling multistate An onsite environmental assessment of this sporadic Salmonella case exposure data point (farm, ingredient supplier, processor, known as Project Hg, for case–case binomial restaurant) can then be conducted to identify comparisons (6). the contributing factors and environmental antecedents that caused the outbreak. Once The binomial comparison functions the source is identified, tracing products as advanced hypothesis generation. forward through distribution can help identify It identifies associations that must be additional cases or help remove contaminated confirmed by product source tracing product from the marketplace. Product and corroborated by other investigation tracing is an important tool to inform the findings. Statistically, binomial epidemiologic investigation, test the hypothesis, comparisons emulate very large case– and control the outbreak. control studies. Results must be cautiously interpreted to avoid spuriously significant Two types of product tracing tools can be results that could lead to errors in used to investigate outbreaks. Traceback identifying the source of an outbreak. investigations are used to trace a product suspected to cause the outbreak through For all analytical studies the significance the supply chain to determine whether it of results depends on the strength of the converges on a common source or supplier. association and the size of the study. Thus, Once a common source or supplier of studies with large numbers of cases are more the contaminated product is identified, likely than studies with few cases to yield traceforward investigations are used to statistically significant results. However, the determine other locations that received the goal of outbreak investigations is to rapidly contaminated product. Both traceback and identify the source to prevent additional cases. traceforward activities can be conducted In this regard, WGS will improve the efficiency 106 Council to Improve Foodborne Outbreak Response
5.4 Test Hypotheses
Figure 5.3. Exposure Distribution Pathways Documented During Informational Traceback of Romaine Lettuce during an Escherichia coli O157:H7 Outbreak. Romaine lettuce from multiple growers in the Yuma, Arizona, growing region were implicated as the source of the outbreak. The lack of association with a single grower ultimately reflected the use of contaminated surface water by multiple growers (7). 5
INVESTIGATION as informational or regulatory endeavors. information: precise illness onset dates, Informational product tracing needs to be exposure dates to the product of interest, conducted quickly to be incorporated into and relative certainty about what foods the epidemiologic studies. Formal regulatory they ate before illness onset. CLUSTER AND OUTBREAK product tracing may be subsequently needed to Traceback of individual cases can provide confirm the distribution of implicated products. important information to corroborate Traceback Investigations. Traceback subcluster data. investigations begin at the point of service • As informational tracebacks progress and where a case-patient was exposed to a single product of interest is identified, the product. Informational, traceback regulatory traceback can be performed if investigations are conducted to help inform necessary to assist in confirming the vehicle. the epidemiologic investigation and can be These regulatory tracebacks enable detailed the final step in confirming the outbreak record collection and documentation of the vehicle (http://mnfoodsafetycoe.umn.edu/wp- product of interest through the supply chain. content/uploads/2015/10/Product-Tracing- • Once an informational traceback is initiated, in-Epidemiologic-Investigations.pdf). specific information is necessary from the • If two or more case-patients report the same case-patients within the subcluster and from point of service, specific information must be the point of sale. As the traceback continues, collected from this subcluster so a traceback establishment types will change and investigation can be initiated. questions about the handling of the product of interest, time frames, and available record Ideal subclusters contain case-patients need to be amended accordingly. who can provide the following 2020 | Guidelines for Foodborne Disease Outbreak Response 107
5.4 Test Hypotheses
Information collected from each subcluster • Point-of-sale information serves as one leg of the overall traceback investigation. Distribution chains from multiple List of ingredients in menu items or traceback legs are documented and compared purchases of interest. to identify commonalities. Convergence of Time frame of interest for distribution multiple legs of a traceback on a specific record collection (determined by facility assists in targeting resources for considering case-patient exposure dates, environmental assessments, inspections, and/ product shelf life, shipment frequency, or sampling. In addition, information from and other pertinent factors). the traceback is continuously evaluated as Identity of all suppliers of the product of part of the evidence for the overall outbreak interest to the point of sale. investigation; convergence reinforces the hypothesis generated by the epidemiologic Frequency the product of interest is investigation. ordered by the point of sale. Product handling and inventory
Informational traceback investigations 5 management in the facility (example: First continue until the product of interest is in First Out). INVESTIGATION CLUSTER AND OUTBREAK followed as far back through the supply chain as possible. Interpretation of the traceback can Point of sale handling of shipments and be challenging and should not be done without documentation of receipt of the product consideration of the epidemiologic, laboratory, of interest. and environmental information collected Storage and transportation practices, during the investigation. If no convergence potential cross contamination; products on a single supplier is identified, reevaluate with common source materials. the hypothesis. Informational tracebacks are Distribution records (e.g., invoices, order challenging and can be limited by a case- forms, bills-of-lading) for the time frame patient’s ability to accurately remember his or of interest that are available at the point her food history, poor record-keeping, lack of of service/sale. Note gaps in or concerns common product identifiers through the supply about record keeping. chain, co-mingling, and many other factors. Therefore, lack of convergence of a traceback Traceforward investigations. Tracing does not necessarily rule out a vehicle as the products forward in the supply chain can source of the outbreak. determine where contaminated products were distributed and enable their removal from Important information for initiation of the supply chain (Chapter 6). Traceforward informational tracebacks: investigations also are an important tool to • Subcluster information identify additional case-patients who were exposed to contaminated products. In the Exposure dates to product at point of sale hypothesis-testing phase of an outbreak (including location name and address). investigation, tracing a suspected product Identification of specific menu items or forward can identify additional points of sale purchases. that received the suspected product. Enhanced surveillance efforts in areas where suspected Documentation of purchase of product products were distributed can be an effective (e.g., credit card, shopper card). way of identifying new clinical cases. Linking points of sale of suspected products with 108 Council to Improve Foodborne Outbreak Response
5.4 Test Hypotheses
additional clinical cases provides additional assessment. To stop the current outbreak and evidence about the outbreak source. prevent future ones, investigators must identify both how (contributing factors) and why Communication of product tracing (environmental antecedents/root causes) the information. Product tracing is always food became contaminated so effective controls multijurisdictional and requires strong can be put in place (Table 5.2). collaboration between public health and regulatory agencies. Predetermined lines Goals of an environmental assessment: of communication should be in place to effectively move information between • Identify contributing factors the necessary parties. Updates on the Factors that introduce or otherwise permit epidemiologic investigation being conducted contamination and relate to how the by the public health agency may greatly agent got onto or into the food vehicle. impact the traceback being conducted by the Factors that enable proliferation or regulatory agency and vice versa. growth of the agent and relate to how the
5 Special considerations need to be given bacterial agent could increase in numbers to distribution information collected by and/or produce toxins before the vehicle regulatory agencies because it may be was ingested. protected from disclosure by confidentiality Factors that enable survival or fail to agreements. Investigational partners should inactivate the contaminants and refer have agreements in place to allow for the to processes or steps that should have lawful exchange of the information (Chapters eliminated or reduced the microbial agent. INVESTIGATION 3 and 7). • Identify environmental antecedents (root 5.4.2 Environmental assessments. When causes) that enabled the system failure a food-production, food-processing, or food- Assessing the internal system components CLUSTER AND OUTBREAK service establishment is identified as being (e.g., people, equipment, processes, associated with a foodborne illness outbreak, foods, and economics) and their effect on environmental health and/or regulatory allowing the system failure to occur officials should conduct an environmental
Table 5.2. Differences between Routine Inspections and Environmental Assessments
ROUTINE INSPECTION COMMENT • Nontargeted • Targeted • Regularly scheduled • Response to an outbreak • Snapshot of current day • Focus on the past • Code/regulation-based • Outbreak information-based • Assessment of current conditions • Examination of processes and problems during outbreak • Identification of violations • Identification of system failures • Identification of underlying factors that enable the system failure
An environmental assessment is a systematic, detailed, science-based evaluation of environmental factors that contributed to the introduction and/or transmission of agents that cause an illness in an outbreak. Environmental assessments are conducted in response to an outbreak and address specific food and process(es) to identify the outbreak’s cause. The environmental assessment is guided by epidemiologic and laboratory information and examines how the causative agent, host factors, and environmental conditions interacted to result in the system failure and people becoming ill. 2020 | Guidelines for Foodborne Disease Outbreak Response 109
5.4 Test Hypotheses
Identifying and address root causes of • Complete the report: Prepare a summary of outbreaks that appear to be part of a the findings that includes detailed diagrams, pattern. descriptions, and results. Incorporate this report into the outbreak investigation report. Five main steps in conducting an environmental assessment: The timing of an environmental assessment • Plan and prepare: Members of the outbreak depends largely on the specifics of the investigation team review epidemiologic outbreak and available information but should information, product tracing information, be initiated as soon as possible (ideally an initial laboratory results, and food facility site visit within 24–48 hours after identification information. Roles and responsibilities, of the establishment). Early investigation intended outcomes, sampling plans, and and collection of food and environmental ways the team will communicate during the specimens will best reflect the conditions at the site visit should be determined at this step. time of the outbreak. In addition, possible food vehicles can be discarded or grow old, and • Visit the site: Observe the facility, and persons involved in the production, processing, 5 evaluate its practices. Collect records and storage, transportation, or preparation of samples pertinent to the investigation. INVESTIGATION CLUSTER AND OUTBREAK the item can change their practices and Information that can be collected as part of procedures. If investigators have identified a the visit includes common location and a profile of symptoms How food moves through the among ill persons that indicates whether the establishment (physical flow diagram). illness agent is likely to be viral, bacterial, How food is processed and handled within toxic, or chemical, they often can begin an the establishment (process flow diagram). environmental assessment based on possible factors more likely to be associated with that Policy and procedures in place at the illness-causing agent. As more information establishments and interviews with becomes available, investigators may need to responsible parties about the execution of make additional trips to the establishment to policies and procedures. investigate the additional lines of inquiry. Ill employee records. Communication of environmental assessment Sales records for the suspected food item. findings is vital. Share results of the Employee interviews. environmental assessments with the outbreak Product coding and distribution investigation team as soon as possible. This information if food is suspected to have information may change the course of the arrived at the facility contaminated. investigation or confirm the suspected food item causing the outbreak. Sharing findings • Assess information: Review information to with industry partners on the contributing identify the outbreak’s contributing factors factors and environmental antecedents that led and environmental antecedents. to contamination is key to improving hazard • Recommend prevention and control identification and implementing control strategies: Control strategies reflect steps measures (8). that should be taken immediately to stop the outbreak and prevent further spread of 5.4.4 Laboratory testing of food products the agent. Longer term strategies reduce the and environments. Targeted sampling of likelihood of future outbreaks at this type of food items and environments of interest in the establishment (Chapter 6). outbreak investigation can help confirm the 110 Council to Improve Foodborne Outbreak Response
5.4 Test Hypotheses
food causing illness. Targeted sampling occurs known to persist in manufacturing and when partners working on the epidemiologic processing environments. Identification of a and traceback investigations share information pathogen in a processing environment that about products and establishments of interest. was linked by epidemiologic and traceback Coordinate with the testing laboratory and information to clinical cases supports consider sampling products and storing confirmation of the outbreak vehicle. appropriately for potential future testing to • WGS is being used to perform molecular reduce the chance the product of interest will subtyping on pathogens recovered from be unavailable for sampling later. foods and environments impacting foods. • Sampling products of interest early in The high resolution of WGS increases the epidemiologic investigation can help confidence in the relatedness of pathogens quickly bring an investigation together, from products and environments to clinical especially if the products of interest are shelf samples. Food or environmental samples stable. In 2017, state and local authorities that are closely related by WGS can launch sampled soy nut butter reported by case- retrospective outbreak investigations, in 5 patients associated with an outbreak of which laboratory evidence from the products E. coli O157:H7 (9). The positive samples or environments drives the epidemiologic generated by that early sampling was used as investigation. Retrospective outbreak evidence to suspend the registration of the investigations often lead to the swift facility manufacturing the product. Not all identification of the outbreak source. product sampling occurs at the outset of an 5.4.5 Coordination of epidemiologic, investigation. Traceback investigations can INVESTIGATION traceback, and sampling activities. identify locations along the supply chain to Whether the outbreak is restricted to one collect samples. jurisdiction or involves multiple jurisdictions, • Food and environmental sampling enables notification and updates should be provided CLUSTER AND OUTBREAK investigators to directly test hypotheses to other interested agencies following the generated during an investigation, often Special Considerations for Multijurisdictional picking up where analytic studies leave off. Investigations (Chapter 7). By gathering information about items of interest (such as food items or ingredients • Arrange for the outbreak investigation and commonly consumed at a restaurant in control team to meet daily and to regularly question; animals to which case-patients update the entire outbreak control team. In were exposed before illness; or other less particular, if the outbreak has gained public common environmental exposures, such as attention, the public information officer needs contaminated milk crates), investigators can to prepare a daily update for the media. target very specific items or areas to sample • During investigation of outbreaks involving for microbiologic testing. When combined events or establishments, maintaining with the case series with binomial exposure close collaboration between epidemiology assessments, such testing can quickly hone a and environmental health is particularly list of suspected products to a single source. important. Interview results from persons • Sampling also can be used to illuminate who attended the event or patronized the the root cause of product contamination, establishment will help environmental especially when done in partnership with the health specialists focus their environmental grower or product manufacturer. Pathogens assessments by identifying likely agents such as Salmonella and L. monocytogenes are and food vehicles. Similarly, results of 2020 | Guidelines for Foodborne Disease Outbreak Response 111
5.4 Test Hypotheses
interviews of food workers and reviews of forward case information to epidemiologists food preparation can identify important for every new potentially outbreak- differences in exposure potential that should associated case they receive. Doing so be distinguished in interviews of persons ensures rapid enrollment of new cases in the attending the event or patronizing the outbreak investigation studies. Similarly, as establishment. For example, environmental investigators acquire information from case- health investigators might determine that patients about exposures in restaurants and food items prepared only on certain days other licensed facilities, they should rapidly or by certain food workers are likely to forward that information to environmental be risky. These refinements also can help health specialists to ensure rapid establish the need for or advisability of identification of commodity ingredients and collecting fecal samples from food workers their distribution sources. or food and environmental samples from the • During the early stages of an investigation, establishment. efforts to identify mode of transmission and • During the earliest stages of the food vehicle require close coordination of 5 investigation, patrons need to be interviewed the outbreak team under the leadership of
rapidly. However, the focus of outbreak epidemiology. After identification of a likely INVESTIGATION CLUSTER AND OUTBREAK activities is likely to shift to interviews of food vehicle, efforts to identify the source food workers, environmental assessments of contamination and contributing factors of the establishment, and review of food- require engagement of local, state, or federal preparation procedures as the investigation food-regulatory programs. As the investigation progresses. proceeds, the outbreak investigation and • During investigation of outbreaks detected control team should always consider whether by pathogen-specific surveillance, the public any information indicates the outbreak might health laboratory needs to immediately be multijurisdictional (Chapter 7).
5.5 Evaluate Evidence to Solve Point of Contamination and Source of the Food
5.5.1 Evaluate evidence. Identifying the Evidence from each of these pillars of the source of contamination and taking action to outbreak investigation is evaluated in concert prevent additional illnesses requires effective to determine whether the data support the and timely integration of three types of data: conclusion that a suspected food or other exposure caused the outbreak. Investigators • Epidemiologic data that describe illness typically determine that they have identified distributions and enable analysis of common the likely source of the outbreak when they exposures. have clear and convincing evidence from two • Traceback and environmental assessment pillars. In rare instances, data from one pillar data that identify common contamination alone might be sufficient to determine the points in the distribution chain. likely source of an outbreak (e.g., complaints or point source clusters linked to a meal or • Testing data that identify outbreak- single event). In investigations of products with associated strains in implicated foods or in a short shelf life (e.g., unpasteurized milk or environmental samples linked to the foods. leafy greens), conducting testing on products 112 Council to Improve Foodborne Outbreak Response
5.5 Evaluate Evidence to Solve Point of Contamination and Source of the Food
during the likely period of contamination 5.5.2 Solve point of contamination might be impossible and investigators must rely and source of the food. The outbreak on evidence from the other pillars to determine investigator’s job is to use all available the likely source of the outbreak. information to construct a coherent narrative
Box 5.1. Questions to Consider When Associating an Exposure with an Outbreak
Strength of association • How strong was the association between illness and the implicated item? (The strength of the association increases with the size of the odds ratio or relative risk: 1 = no association; <5 = relatively weak association; 5–10 = relatively strong association; >10 = very strong association.) • Was the finding statistically significant? (<0.05 is a traditional cutoff p value, but in small studies, even relatively strong associations might not reach this level of significance. Conversely, in large studies examining many exposures, relatively weak associations might reach this level of significance by chance or as an effect of confounding.) 5 • Were most ill persons exposed to the implicated item? “Yes” is desirable but might not always be apparent if the implicated item is an ingredient in multiple food items.) Timing • Did the exposure to the implicated item precede illness by enough time for a reasonable incubation period? • Do the time windows obtained during traceback and traceforward investigations correlate with reported dates of production, distribution, and purchase of the implicated item? INVESTIGATION Dose–response effects • If assessed, were persons with greater exposure to the implicated item more likely to become ill or have more severe clinical manifestations?
CLUSTER AND OUTBREAK Plausibility • Is the association consistent with historical experience with this or similar pathogens? Can investigators develop a rational explanation for opportunities for contamination, survival, and proliferation of the pathogen in the implicated item? (If otherwise strong and consistent results cannot be readily explained, the outbreak might herald emergence of a new hazard, which will require additional studies to confirm.) • Is the geographic location of ill persons consistent with the distribution of the implicated item? (Discrepancies might be explained by gaps in surveillance, product distribution data, or involvement of additional food products.) Consistency with other studies • Studies associated with current investigation Do the results of traceback and traceforward investigations suggest a common source? Have environmental health assessments identified problems in the production, transport, storage, or preparation of the implicated item that would enable contamination, survival, and proliferation of the pathogen in that item? If the pathogen was isolated from ill persons and from the implicated item, do subtyping results (e.g., WGS analysis) confirm the association? • Studies not associated with current investigation Is the association between the pathogen and the implicated item consistent with other investigations of this pathogen? 2020 | Guidelines for Foodborne Disease Outbreak Response 113
5.5 Evaluate Evidence to Solve Point of Contamination and Source of the Food of what happened and why. This begins with food-product and environmental testing. When the initial detection of the outbreak and all of these data elements support and explain formation of hypotheses based on the agent’s the primary hypothesis, investigations can ecology, microbiology, and mechanisms of draw very strong conclusions (Box 5.1). transmission in addition to the descriptive epidemiology of reported cases. Results of Outbreak investigators should be open to new subsequent analytic studies (e.g., cohort or developments and new twists to old problems. case–control study results) must be integrated New hazards are frequently identified through with results of product tracing, food worker outbreak investigations. However, they should interviews, environmental assessments, and be wary of explanations that depend on implausible scenarios.
5.6 Implement Control Measures, Investigation Closeout, and Reporting 5 INVESTIGATION CLUSTER AND OUTBREAK
5.6.1 Deciding an outbreak is over (Chapter considered before continuing investigational 6). Outbreaks end when cases are no longer activities. Experience reminds us—again detected or reported. Outbreak investigations and again, unfortunately—that even can continue after the outbreak ends, given seemingly well-executed investigations can be product tracing and observations on practices inconclusive. Small sample sizes, multivehicle at suspected firms may take longer to obtain. situations, “stealth” food items that may not be In addition, control measures need to be recognized, and foods with high background evaluated if the source of the outbreak was rates of consumption are only some of the identified. For outbreaks where the source factors that can reduce the effectiveness of has not been identified, consideration to standard epidemiologic methods and make the prioritization of resources and expected investigations extremely difficult. outcome of the investigation should be 114 Council to Improve Foodborne Outbreak Response
References
1 CIFOR Outbreaks of Undetermined Etiology (OUE) Guidelines. https://cifor.us/clearinghouse/cifor-oue- guidelines 2 Centers for Disease Control and Prevention. SEDRIC: System for Enteric Disease Response, Investigation, and Coordination. https://www.cdc.gov/foodsafety/ outbreaks/investigating-outbreaks/sedric.html 3 Hennessy TW, Hedberg CW, Slutsker L, White KE, Besser-Wiek JM, Moen ME, et al. A national outbreak of Salmonella enteritidis infections from ice cream. The Investigation Team. N Engl J Med. 1996;334:1281–6. 4 McCollum JT, Cronquist AB, Silk BJ, Jackson KA, O’Connor KA, Cosgrove S, et al. Multistate outbreak of listeriosis associated with cantaloupe. N Engl J Med. 2013;369:944–53. 5 Centers for Disease Control and Prevention. Foodborne Active Surveillance Network 5 (FoodNet). Population survey atlas of exposures. 2006–2007. https://www.cdc.gov/foodnet/PDFs/ FNExpAtl03022011.pdf 6 Oregon State University. Project (Hg) Mercury. https://health.oregonstate.edu/fomes/mercury 7 Bottichio L, Keaton A, Thomas D, Fulton T, Tiffany A, Frick A, Mattioli M, Kahler A, Murphy J, Otto
INVESTIGATION M, Tesfai A, Fields A, Kline K, Fiddner J, Higa J, Barnes A, Arroyo F, Salvatierra A, Holland A, Taylor W, Nash J, Morawski BM, Correll S, Hinnenkamp R, Havens J, Patel K, Schroeder MN, Gladney L, Martin H, Whitlock L, Dowell N, Newhart C, Watkins LF, CLUSTER AND OUTBREAK Hill V, Lance S, Harris S, Wise M, Williams I, Basler C, Gieraltowski L. Shiga Toxin-Producing E. coli Infections Associated with Romaine Lettuce - United States, 2018. Clin Infect Dis. 2019 Dec 9. pii: ciz1182. doi: 10.1093/cid/ciz1182. [Epub ahead of print] 8 International Association for Food Protection. Leveraging current opportunities to communicate lessons learned from root cause analysis to prevent foodborne illness outbreaks. https://www. foodprotection.org/publications/food-protection- trends/archive/2018-03-leveraging-current- opportunities-to-communicate-lessons-learned-from- root-cause-analysis-to- 9 Centers for Disease Control and Prevention. Multistate outbreak of Shiga toxin–producing Escherichia coli O157:H7 infections linked to I.M. Healthy Brand SoyNut Butter (final update). https://www.cdc.gov/ ecoli/2017/o157h7-03-17/index.html CHAPTER 6
Control Measures and Prevention
CHAPTER SUMMARY POINTS
• Effective control measures include a combination of immediate controls to stop the current outbreak and longer term controls to prevent future outbreaks. • Effective and timely information sharing among investigation and response partner agencies, impacted food industries, and the public is essential to control foodborne illness outbreaks. • Appropriate control measures vary depending on whether the implicated food was contaminated At a single local food-service or retail food establishment, or Before being commercially distributed. • Three strategies used to stop foodborne illness outbreaks are Controlling contaminated foods at their source. Controlling contaminated food products that have left the source (e.g., recalls). Preventing secondary spread of infection. • To identify appropriate control measures, information from different sources, such as epidemiology, laboratory, and environmental health should be integrated into the outbreak response. • General control measures are often followed up with more specific controls as investigators learn more about the source(s), contributing factor(s) and root cause(s) (i.e., antecedents, underlying reasons) of the outbreak. • Investigation and control teams should use the after-action review processes to: Assess the strengths and limitations of past responses. Identify action steps to improve future responses. Track corrective actions using the organization’s continuous process improvement programs. Prevent outbreak recurrence by applying lessons learned regarding root cause and contributing factors. • Foodborne illness investigation reports are used to accurately document actions and conclusions to improve future investigation practices and make changes to prevent future outbreaks.
URLs in this chapter are valid as of July 29, 2019. 116 Council to Improve Foodborne Outbreak Response
6.0 Introduction
6.0.1 The purposes of outbreak • Outbreaks associated with contaminated investigations are to stop the current commercially distributed foods may outbreak, determine how contamination originate from a commercial food occurred, and implement measures to manufacturer or agricultural commodity prevent future outbreaks by addressing distributed to multiple sites. The resulting the root cause(s) in the implicated, and foodborne illness may be linked to a variety potentially other, facilities. Whereas the of food establishments or to foods prepared investigation is critical for understanding the in the home. These outbreaks are usually cause, effective and timely control measures multijurisdictional and require coordinated are critical for stopping the outbreak and intervention by local, state, territorial, tribal, preventing reoccurrence of illness. Identifying and federal agencies and the industry. the root cause(s) of foodborne illness improves the effectiveness of prevention efforts. 6.0.2 Effective communication between team members and with other response The rapid and accurate response to foodborne partners is essential during all phases of illness is critical. the investigation to ensure opportunities to quickly implement or improve Investigators from all three primary disciplines control measures are not missed. The (epidemiology, environmental health, and exchange of specific actionable information laboratory) must quickly assess information is paramount to success. Communication and identify suspected foods or facilities to 6 within the response team and with other
prevent additional illnesses. stakeholders during an outbreak response is of primary importance. For all foodborne There are generally two types of foodborne illness outbreaks, early sharing of information disease outbreaks, and each requires different between epidemiologists, laboratory staff, and control measures. environmental health specialists is critical to PREVENTION • Local outbreaks may be associated with determine what control measures to implement food-preparation errors or contamination to prevent foodborne illness. Timely food- of food by food workers at the site of supply investigations, such as product tracing preparation or distribution, e.g., foods and environmental assessments, can better prepared at home, food-service, and retail define the food vehicle(s) that need to be CONTROL MEASURES AND CONTROL MEASURES AND food establishments. Local outbreaks controlled and identify the contributing factors typically are controlled through local actions. and environmental root causes that led to foodborne illness (Chapter 5).
6.1 Information-Based Decision Making
6.1.1 Investigation and control teams traceforward) investigations, environmental should be prepared to act at any point assessments, or other investigative processes. in the investigation when credible Waiting for laboratory results, medical information identifies opportunities to diagnosis confirmation, or implication of a control or mitigate disease transmission. specific food may not be necessary before Controls can be implemented concurrently implementation of initial control measures to with product tracing (i.e., traceback, prevent additional exposures. 2020 | Guidelines for Foodborne Disease Outbreak Response 117
6.1 Information-Based Decision Making
Control measures typically progress from • Assess potential risks on the basis of general to specific as investigations gather information provided by each discipline. more information and should be implemented • Assess availability of resources needed to immediately whenever their need becomes implement controls (e.g., legal authorities, apparent. General precautionary control equipment, and staff). measures that have high potential for public health benefit and low impact on business • Identify priority control measures, and operations are usually not controversial and clarify expectations among team members can be implemented relatively quickly in the about the timeliness and completeness of field by the regulatory authority. Examples control efforts. include holding a suspected nonperishable • Implement control measures. food from sale or screening for and excluding • Reassess and adjust control measures as an ill employee. Decisions to implement more additional information is gathered. costly controls, such as recalling a food from distribution or closing a facility, should be The quality of information is related to based on clear and convincing evidence that multiple factors (Chapter 5). Evaluate food from the facility caused illness or that epidemiologic, laboratory, environmental an imminent hazard to health exists. These health, and other evidence together to decisions should involve input from the entire determine the degree to which the integrated
response team, including risk communication data are consistent with each other, biologically 6 specialists and legal advisors (Chapter 2). plausible, and sufficiently strong to support Depending on the complexity of the outbreak, implementation of control measures. PREVENTION CONTROL MEASURES AND input from federal agencies, trade associations, or other industry and academic experts may 6.1.3 Investigation and control teams be necessary. must balance the likelihood that control measures will prevent further illness 6.1.2 Investigation and control teams against other consequences (Box 6.1). should use a systematic process to evaluate Inaction or delayed action in the face of information and regularly reassess control ongoing exposure can result in additional measure decisions. Sometimes the type of illnesses. Conversely, aggressive control control measures needed to stop an outbreak interventions, such as recalling food or is readily apparent early in the investigation closing a food establishment, can have legal (e.g., significant food temperature or risk factor or economic consequences for food workers, violations). More commonly, however, key employers, communities, and entire food information is initially unavailable about the industries. Investigation and control team source, contributing factors, and root causes of members should not delay initiating steps to foodborne illness outbreaks. protect public health if available information indicates the need to act. Typical steps in the evaluation include the following: • Send a team to the likely source as soon as possible. • Inform and involve the owner or manager of the implicated establishment. 118 Council to Improve Foodborne Outbreak Response
6.1 Information-Based Decision Making
Box 6.1. Questions to Address when Considering Control Options
• Is the contaminant causing the disease highly pathogenic, virulent, or toxic? Are susceptible populations exposed? • Is the causative microorganism highly infectious and likely to be a source of secondary infections in the community? • How effective, and how costly, is the proposed control measure likely to be? • Who would play a role in implementing the control (government agency, food industry, or others)? What information will they need to act? • Is a narrow, focused action possible—such as recalling a specific group of products or notifying only the persons most likely to have been exposed—rather than a more general recommendation to avoid consuming a general category of food or notifying the public? • Will the actions affect only one business or an entire industry? How much economic or operational burden will be placed on the public who will need to respond on the basis of the proposed action? • As they ponder these questions, investigation and control team members must recognize that a rapid response is critical if the threat of serious illness and death is ongoing.
Studies not associated with current investigation.
6 6.2 Communications With the Public
Agencies should anticipate, prepare for, • Follow agency communication protocols. and allocate resources to respond to and Prepare communication following the manage public concerns related to any public agency’s risk communication protocols. health messaging about the investigation. All Seek assistance from the agency public PREVENTION members of the outbreak investigation and information officer or the public information control team (epidemiology, environmental officer at another agency if the agency with health, and laboratory) and health department jurisdictional responsibility does not have leadership should provide input into the this resource. decision to make a public notification (Box 6.2) • Provide information about the disease, CONTROL MEASURES AND CONTROL MEASURES AND 6.2.1 Messages to the public about including symptoms, mode of transmission, foodborne disease outbreaks should follow prevention, and actions to take if illness best practices for risk communication and occurs. provide objective, fact-based information • Include information about what is known, about the outbreak. what is not known, and what officials are doing to learn more. • Ideally, before an outbreak occurs, prepare templates for public messages and have • Do not speculate about the outbreak. them reviewed by appropriate staff, Sharing preliminary or unconfirmed including legal counsel. Use the templates information with the public may result in consistently during the investigation. For undue worry if there is no definite action to examples of communication templates, see be taken (i.e., avoidance of a certain food). the CIFOR Clearinghouse (https://cifor. Such announcements often result in inquiries us/clearinghouse/cifor-toolkit-focus-area-3- from concerned citizens and the media, and communications). the resulting expanded workload can rapidly 2020 | Guidelines for Foodborne Disease Outbreak Response 119
6.2 Communications With the Public
Box 6.2. Questions to Address when Considering Whether Public Notification is Necessary
• What is the potential severity of disease and risk for additional illnesses (e.g., secondary infections in the community? • Is medical treatment necessary for persons who might have been exposed to the etiologic agent? If so, urgent public notification is critical. • Is public reporting of suspected illness necessary to determine the scope of the outbreak? If so, public notification might be appropriate. • Does risk for exposure still exist? People take food home from restaurants, so public notification still might be appropriate. • Are large numbers of unknown persons likely to be ill with highly infectious agents, such as norovirus or Shigella? If so, an advisory that ill persons should stay out of work or restrict activities may help prevent secondary transmission at other food establishments, day care, and healthcare facilities. • Is the source of the outbreak past its shelf life so no further risk exists to the public? If so, public notification may not be needed.
divert resources from the investigation and • Means of notification depend on the public
control team and increase pressure to quickly health risk and the target population and 6 name the source of the outbreak. might include press releases, radio, television, PREVENTION CONTROL MEASURES AND • Ensure that officials prepare talking points fax, telephone, text messaging, email, Web to respond to media inquiries and social posting, social media, or letters. media questions, if needed. The Colorado • Provide clear and actionable information Integrated Food Safety Center of Excellence about how to handle a suspected product developed the Communications Toolkit: (discard, special preparation instructions, or Media Relations to help agencies work return to place of purchase) or whether the constructively with the media during local jurisdiction is interested in obtaining foodborne illness outbreaks (1). the product from households that still have it. • Work closely with public information officers • Consider notifying area clinicians and
to ensure that consistent messaging is used healthcare facilities if an increase is expected to answer inquiries. This collaboration can in the number of people seeking healthcare reduce the potential for confusion or panic after public notification. among consumers and industry. 6.2.3 If public notification is expected to • Maintain effective, accurate, and consistent generate considerable public concern and/ communication with other agencies (i.e., or media inquiries, consider setting up local, state, territorial, tribal, and federal) an emergency hotline for the public and involved in, or impacted by, the investigation. media. Train people answering the phones to 6.2.2 Notify the public when actionable give consistent responses. Give them talking information is available that the public points or frequently asked questions and can act on to prevent additional illness answers. Consider staffing the hotline after (Box 6.3). Attempt to reach all members of hours to answer phones after the early evening the population at risk, including non–English- news or to respond to questions posed on speaking and low-literacy populations. social media. 120 Council to Improve Foodborne Outbreak Response
6.2 Communications With the Public
Box 6.3. Notifying the Public About Actionable Information
Early public announcements should reinforce basic food safety messages and inform the public about how to contact appropriate authorities to report suspected foodborne illnesses. Educational materials on food safety targeted at the public are available from the Partnership for Food Safety Education (http://www.fightbac.org) and the Centers for Disease Control and Prevention’s Food Safety website (https://www.cdc.gov/foodsafety). The following specific food safety messages are important to communicate to the public.
• Personal protection from disease outbreak: Thoroughly wash hands with soap and warm water after using the bathroom and before preparing or eating food. Also wash hands after changing diapers, assisting a child at the toilet, and handling animals or animal waste. Hand washing is the single most important measure to protect the public’s health. At home or at a social gathering (e.g., potluck dinner), avoid eating food that has not been handled properly (e.g., hot food that has not been kept hot, cold food that has not been kept cold).
• Proper food preparation: Thoroughly cook food; keep hot food hot and cold food cold; thoroughly clean all food- preparation surfaces and utensils with soap and water; avoid contaminating food that will not be cooked, such as salads, with food that must be cooked, such as raw meat or chicken products; and 6 wash hands frequently with soap and water.
If you are ill with diarrhea or vomiting, do not prepare food for others until at least 72 hours after you are free of diarrhea or vomiting. Wash hands before and during food preparation.
PREVENTION • Actions if someone in the household or childcare, or institutional setting has diarrhea or vomiting: If a norovirus-like illness is involved, emphasize the importance of thorough cleaning and sanitation of high-risk transmission surfaces, such as toilet seats and flush handles, washbasin taps, and washroom door handles.
• Appropriate community guidance, references, and educational materials are available at CONTROL MEASURES AND CONTROL MEASURES AND https://www.cdc.gov/norovirus/preventing-infection.html.
6.3 Communications With Response Partners and Stakeholders
Early communication with healthcare of transmission is clear or a food or facility providers, the food industry involved, and has been implicated. Control measures at this others impacted by the outbreak can increase point typically focus on preventing secondary case detection, reduce the risk for secondary spread by known cases and communicating transmission, and help identify the source with healthcare providers and the public of contamination. If the pathogen causing about precautionary measures they can take enteric illnesses is known, use of general to prevent illness transmission of the identified communicable disease control measures may pathogen. limit further spread, even before the mode 2020 | Guidelines for Foodborne Disease Outbreak Response 121
6.3 Communications With Response Partners and Stakeholders
6.3.1. Effective communication with other • Implement control measures to prevent agencies involved in the investigation or further cases. potentially impacted by the response helps staff from multiple agencies take timely actions Food-industry representatives often have to prevent further illnesses. During multistate detailed knowledge about typical food- outbreaks, others involved might include handling, storage, and distribution practices agencies and organizations at the local, state, that can guide investigation and control territorial, tribal, and federal public health efforts. Early sharing of clear, credible, and and regulatory levels (Chapter 7). A consistent objective information often motivates firms public message alleviates confusion and reduces to voluntarily bolster efforts to comply with the potential for panic among consumers. standard food safety and communicable disease control measures, such as 6.3.2 Communications with healthcare providers should include reminders and • Excluding or restricting ill persons from instructions to be shared with ill persons about food handling. personal hygiene, ways to avoid spreading • Eliminating bare-hand contact with ready- infection, and infection control precautions to-eat foods. for hospitalized patients and residents of • Proper handwashing. long-term–care facilities. Instruct healthcare providers to report suspected illness to • Thorough cooking. 6 local health departments for follow-up and • Effective cleaning and sanitizing procedures. interviews, especially when ill persons work in PREVENTION CONTROL MEASURES AND settings where the risk for disease transmission It is often helpful to provide a written summary is most likely, such as in food establishments identifying key information, including the type and childcare and healthcare facilities. Advise of agent (viral, bacterial, chemical, toxic), the healthcare providers about whether to collect exposure time period (particularly if exposure clinical samples for analysis, if indicated. is potentially ongoing), and whether a single point source or multiple different exposures 6.3.3 Early communication with impacted most likely caused the illnesses. food establishments, commodity groups, or food industries likely impacted by the The Communications Toolkit: Industry public notification can assist them to Relations developed by the Colorado Integrated Food Safety Center of Excellence • Prepare for media enquiries. is an example of resources available to help • Consider how they can cooperate with the agencies communicate effectively with the food investigation to identify the cause(s). industry during foodborne illness outbreaks (1).
6.4 Control Measures
Although most reported foodborne illness may be needed at multiple points along the outbreaks are investigated and controlled at distribution network and in the impacted the local level, site-specific food-safety controls communities (Figure 6.1). 122 Council to Improve Foodborne Outbreak Response
6.4 Control Measures
Figure 6.1. Controlling the Source and Communicating with the Public
At the source: Stop further production of contaminated food at the implicated food establishment.
Control any contaminated food remaining at the establishment.
In distribution: Remove contaminated 6 food from
commercial distribution.
In the
PREVENTION community: Notify the public not to consume contaminated CONTROL MEASURES AND CONTROL MEASURES AND products that may be in their homes.
Appropriate control measures vary depending on whether the implicated food is associated with a food-service/retail food establishment or is a manufactured food that has been commercially distributed. The outbreak response team must determine as soon as possible whether one facility or multiple facilities are involved. 2020 | Guidelines for Foodborne Disease Outbreak Response 123
6.4 Control Measures
6.4.1 Implement initial control measures contributing factors and the environmental at an implicated facility on the basis of root causes that led to the outbreak. investigation findings and review of what is known about other outbreaks caused 6.4.2 Coordinate onsite investigation, by the agent and the food establishment’s environmental assessment, and control food-safety history. Credible epidemiologic, measures at the implicated facility. laboratory, and environmental health Most foodborne illness outbreaks are local evidence can support early implementation of events investigated and controlled by staff nonspecific control measures at an implicated from local public health agencies. For large- facility, even though a specific food has not yet scale or multijurisdictional outbreaks, staff been identified. from multiple disciplines or agencies may be involved. Staff should identify investigation • Adjust control measures on the basis of and control objectives and clarify agency knowledge of the agent and whether a roles and responsibilities before arriving at food item is suspected. An outbreak caused the implicated food establishment. Initial by Clostridium perfringens has very different clarification of both types of objectives helps contributing factors and control measures ensure that appropriate staff visit the facility. than one caused by norovirus. Controls for a C. perfringens outbreak focus on time and • A team approach is often needed to temperature for food safety, including rapid effectively conduct the onsite investigation cooling, proper hot holding, and reheating. and implement control measures. When 6
Controls for a norovirus outbreak focus on conducting any environmental assessment, PREVENTION CONTROL MEASURES AND identifying and excluding ill employees. Also at least two environmental health specialists ensure proper hand-washing, no bare-hand should be deployed in the field to ensure contact of ready-to-eat foods, disposal or both investigative and control measure embargo of ready-to-eat foods when bare- objectives are achieved. Environmental hand contact occurs and thorough cooking assessment teams visiting facilities for the is not possible, enhanced cleaning and first time must often simultaneously seek sanitizing procedures, and (possibly) changes to complete multiple objectives. A few in the source of suspected high-risk foods examples include communicating with used in the facility. Focusing on pathways firm management to enlist its cooperation, ensuring the safety of foods being served/
commonly linked to the agent are most likely to identify and address the root causes of the sold, placing seizures/embargoes/holds on outbreak. implicated or suspected foods or leftovers, interviewing food workers, assessing foods • Review the establishment’s history for served and processes during the period recurring foodborne illness risk factors, of interest, and collecting documents and previous outbreaks, illness complaints, recall, samples as needed. positive food samples, and correction of serious food-safety hazards. This information • Rapid initial assessments to identify can indicate management’s capability and conditions requiring immediate control willingness to consistently maintain food- measures should be coordinated with ongoing safety controls. Understanding the facility’s investigation activities. Effective control existing level of active managerial or process measures address both the contributing control can guide how the investigation factors that resulted in foodborne illness (what and control team works with management went wrong) and the root cause(s) of the to implement changes needed to address outbreak (why it went wrong at this location). 124 Council to Improve Foodborne Outbreak Response
6.4 Control Measures
6.4.3 Gather samples while they are still • Remove food from sale or prevent available. Early collection of samples while consumption. If evidence from the they are still available can greatly aid in epidemiologic, laboratory, and environmental determining the root causes of foodborne assessment/root cause analysis supports illness (Chapter 5). Discarding suspected food the action, implicated or potentially unsafe can help stop the outbreak, but isolating the foods should be embargoed, seized, placed etiologic agent from the food provides the most under regulatory hold, or otherwise removed convincing evidence a food was the source of from service or sale. Fully document the the outbreak. Use both epidemiologic data information that led to the decision and and guidance from the laboratory to inform the process used to make the decision. decisions about what samples to collect and Issuing a written hold or embargo order how to handle them. establishes clear expectation and regulatory requirements and prevents the establishment 6.4.4 Control measures for localized events owner from serving or destroying the food associated with a single food-service or before the investigation is complete. retail food establishment will usually be established by local public health • Clean and sanitize. If evidence from agencies or state and local food-regulatory the outbreak investigation identifies the agencies. Although all of the following control potential for onsite contamination during measures are recommended, some may be the outbreak, the environmental health specialist must ensure involved equipment 6 more appropriate than others in specific and areas of the facility are thoroughly outbreaks, and full implementation might not be possible in some jurisdictions. Implementing cleaned and sanitized. This process includes the most appropriate control measures as disassembling all equipment and retraining completely and promptly as possible improves staff on proper cleaning and maintenance the effectiveness of those measures. Before procedures for the equipment. The cleaning
PREVENTION using any control measure, the environmental and sanitizing process is particularly health/regulatory specialist must understand important if Salmonella, Listeria monocytogenes, applicable laws and procedures for or norovirus contamination of food is implementing them (Chapter 2). suspected. Industry guidance documents are identified under references.
CONTROL MEASURES AND CONTROL MEASURES AND • Inform and engage facility management • Train food managers and workers. Assess to in implementing controls. Environmental what degree the presence of food-safety risks health specialists should work with the food is due to inadequate food worker knowledge, establishment’s person-in- charge (PIC) inadequate supervision, or lack of active to implement active managerial controls managerial control. Ensure the firm’s food- and create a risk-control plan or consent safety management system is adequate to agreement. Active involvement of the PIC ensure that managers and food workers uses his or her expertise and often increases receive consistent food-safety training commitment to implement controls to appropriate for their job duties. Ensure stop the current outbreak and prevent remedial training is provided, as needed additional outbreaks. The CIFOR Industry so that food managers and workers have a Guidelines outlines, clarifies, and explains functional understanding of the disease (e.g., the recommended role of owners, operators, symptoms, modes of transmission) and the and managers of food establishments in a food-safety practices (e.g., use of procedures foodborne illness outbreak investigation (2). for rapid cooling and thorough cooking 2020 | Guidelines for Foodborne Disease Outbreak Response 125
6.4 Control Measures
and reheating of foods) needed to stop the the latest version of the Food and Drug outbreak and prevent recurrence. Administration (FDA) Food Code (3). • Modify a food process. Assess food- In Salmonella and Shigella outbreaks, production or food-preparation processes at fecal samples should be analyzed for the the establishment using both investigation pathogen because of the likelihood of findings and the best available scientific asymptomatic but infectious food workers. information. Examples of critical steps and Restricting activities of food workers who controls include process times, temperatures, do not comply with the request might be parameters (pH, water activity level), and necessary. label instructions. Implement changes needed Excluding ill food workers is not as simple to consistently prevent contamination of food as it might seem. Food workers may be or the survival and proliferation of disease- reluctant to inform managers of illness causing microorganisms. because of fear of lost wages, reprisal, or • Modify the menu. Eliminate implicated leaving their co-workers short-handed. foods from the menu until adequate control Conversely, managers underappreciating measures are in place to ensure food safety. the risk to public health and their firm’s For example, if shell eggs are implicated, economic viability may be reluctant to remove all foods that contain shell eggs, and relieve food workers of their duties or may substitute pasteurized egg product until the themselves work while ill. 6 investigation is complete and proper controls Facilities with a strong food-safety are in place. culture ensure that both managers and PREVENTION CONTROL MEASURES AND • Remove infected food workers. Ensure food workers are well informed about that ill or infected food workers are alternatives to coming to work while excluded from the workplace or restricted in sick, including alternate jobs that ill food accordance with the Food Code (3) or other workers can perform and allowing ill regulatory requirements unless evidence employees to trade for shifts when their gathered by the investigation team indicates exclusion has been lifted. that a longer exclusion period is needed • Use risk-control plans. Written risk-control (e.g., evidence exists of ongoing norovirus plans or other agreements are used to transmission within the food establishment). identify and focus control measures that
Because many food workers are employed by establishments need for safe operation. more than one food establishment, ensure ill Important aspects of these plans include workers are excluded or restricted from all food establishments where they work. Process changes, such as recipe adjustments or development of a Hazard Food establishment management should Analysis and Critical Control Point plan. conduct daily monitoring of worker health to prevent further contamination Worker training. of food by ill or infected workers. For Adequate oversight measures to ensure example, workers follow proper procedures. . A person ill with vomiting or diarrhea Plans may require should be excluded from the facility. Increased focus on regulatory . Pathogen-specific guidance and other requirements (e.g., additional measures information about restricting and to ensure appropriate handwashing by excluding food workers is available in all employees). 126 Council to Improve Foodborne Outbreak Response
6.4 Control Measures
Additional measures above and beyond • Notify the public. As control measures are regulatory minimum requirements (e.g., implemented at the source, public notification extra temperature checks and logging of can be an effective way to prevent additional temperature). illnesses and further disease transmission, but • Close food establishments. Facilities that it must be used judiciously. If the outbreak cannot safely remain in operation must be involves only one facility, carefully consider closed in accordance with applicable local whether public notification is truly necessary. and/or state regulations. A facility linked See 6.2 for details. to an ongoing foodborne illness outbreak, • Monitor control measures. The strategy for in which significant noncompliance monitoring short- and long-term correction with regulatory food-safety standards is of the factors within the food establishment documented, is an imminent or substantial that caused the outbreak should be identified health hazard. in writing. Food establishments should • Communicate findings. Effective integrate monitoring steps into their food- communication of the evidence gathered safety management systems (e.g., Active by the investigation and control team can Managerial Control), and regulatory officials be a powerful motivator for establishment should provide the facility with timely management to close or significantly modify follow up inspections so the effectiveness operations. Voluntary actions are often the of control measures can be assessed, modified, or removed when appropriate. 6 most efficient and timely way to reduce risks Public health officials should maintain to the public. If the owner cannot or will not take immediate corrective action to eliminate enhanced surveillance of potentially ongoing food-safety hazards, mandatory exposed populations to ensure controls are closing of the premises may be necessary. effective, secondary spread of infections is not occurring, and systems are in place to
PREVENTION prevent reoccurrence.
6.5 Outbreaks Involving Commercially Distributed Foods
facility, the probability is much higher that
CONTROL MEASURES AND CONTROL MEASURES AND 6.5.1. Control measures associated with commercially distributed foods typically they have moved through various points of require coordination of multiple agencies often complex distribution networks that can across jurisdictional levels, especially span the globe and include a wide range of when an implicated food item is subject locations, including; warehouses, distributors, to recall (Chapter 7). Careful coordination of retail establishments, consumer homes, control measures at the food-manufacturing and food banks. Timely product tracing facility, in distribution channels, and in investigations often identify the point in the consumer homes often is needed to stop production and distribution process where outbreaks linked to commercially distributed the implicated food became contaminated foods. Food manufacturers can range from and where contaminated products may have small facilities with limited local distribution been distributed after that (Chapter 5). The to large, complex facilities capable of type of food products involved and the extent producing huge quantities of diverse products of their distribution often determine which daily. Although contaminated products may regulatory agency leads the implementation still be stored onsite at the manufacturing and coordination of control measures. 2020 | Guidelines for Foodborne Disease Outbreak Response 127
6.5 Outbreaks Involving Commercially Distributed Foods
• Implement onsite controls at the food- or consumer homes and, if so, decide how manufacturing facility. Depending on the contaminated products can most effectively scope of the outbreak and probable point of be removed from the market and consumers contamination, most of the specific onsite notified when appropriate (Box 6.4). control measures for food-service and retail Food firms have the primary legal food establishments also will be appropriate responsibility to initiate and conduct to control contaminated foods and food- effective food recalls. If the food-regulatory safety risks at other points in food-supply agency has adequate information to chains where contamination was introduced. implicate and accurately identify a Given the size and complexity of many contaminated food item, that agency of these establishments, timely sharing of will take the lead on working with the the most specific and accurate information manufacturer to initiate recall activities. available (e.g., product descriptions, lot Consider the capabilities of the firm and codes, and periods of interest) is vital to involved agencies to: notify the public when focusing control measures where they are appropriate, conduct recalls, and verify most needed. their effectiveness. Past recall experience • Determine whether a food recall is and prior recall planning are often good needed. Public health and food-regulatory indicators of likely future performance by agencies need to determine whether the the manufacturer.
contaminated product is still in distribution 6 PREVENTION CONTROL MEASURES AND
Box 6.4. Considerations for Whether to Remove Food from Distribution
Questions to Ask • Is risk to consumers ongoing? • Is the product still in distribution based on product tracing information (Chapter 5)? • Is the product likely to still be in the homes of consumers? • Do the combined epidemiologic, laboratory, and environmental health data support removing food from the market?
Remove the food if • Specific exposure information links the illness with consumption of that food (e.g., through a quality analytic study or other epidemiologic method), even if the pathogen has not been isolated from the food. OR • Definitive lab results show the outbreak pathogen is present in the product. The results must be based on a food sample that is representative of the food eaten by case-patients and has been handled properly to avoid cross-contamination. OR • An investigation at the source reveals adulterated products or other conditions that pose an imminent hazard to health. OR • Epidemiologic association is not significant, but the pathogen, chemical, or other contaminant is so hazardous that the risk to the public is very high (e.g., botulism). Under these circumstances, there may be no analytic controlled studies, but if the descriptive epidemiology (e.g., demographic characteristics of case-patients, geographic distribution, or illness onset) suggests an association between the disease and the suspected food, then removing food from the market might be warranted, even in the absence of confirmed laboratory findings. 128 Council to Improve Foodborne Outbreak Response
6.5 Outbreaks Involving Commercially Distributed Foods
• Contact the federal or state regulatory identified, some processors will voluntarily agency that has jurisdiction over the recall or be compelled to recall all suspected product. FDA regulates the safety of most product to avoid the negative publicity foods moving in interstate commerce, except and the economic impact associated with meat, poultry, fish of the Order Siluriformes multiple recalls of their products. (including catfish), and most out-of-shell egg Recall of food at the processor level products (which are regulated by the U.S. generally requires federal and/or state Department of Agriculture’s Food Safety action. In some jurisdictions, the local health and Inspection Service [FSIS]) (Chapter 3). jurisdiction will embargo (impound) the Both FDA and FSIS have developed food (tagging the food to make sure it is not informational websites to assist their moved or sold, or ordering it destroyed). investigation and response partners. FDA Under the Food Safety Modernization Act developed a general website (4) with (6), FDA can order the embargo of food for Resources for Regulatory Partners, and up to 30 days without a court order. FSIS developed a website with resources for • Remove product from distribution. Once its investigation partner agencies to improve a decision is made to remove food from the communication and sharing of information distribution, the food must be removed as during foodborne illness outbreak quickly and efficiently as possible (Box 6.5). investigations (5). Foods with short shelf lives (e.g., fresh
6 • Initiating a recall. State agencies, FDA, produce, dairy products) generally are
FSIS, and the Centers for Disease Control consumed within the shelf life or discarded. and Prevention (CDC), often contact Foods with longer shelf lives, especially the manufacturer seeking to obtain its frozen foods and foods that may be frozen, cooperation in initiating a food recall. In will be available for extended periods addition, the regulatory authority and/or of time. Prevent additional exposure by PREVENTION the manufacturer may ask retail facilities to ensuring effective recall practices and remove the product from their shelves and public notification. ask distributors to withhold the product Conduct product tracing (traceback, from distribution. traceforward) investigations to better Quickly determining the extent of a recall learn where contaminated products were CONTROL MEASURES AND CONTROL MEASURES AND needed in a large manufacturing plant with distributed and how contaminated products multiple processing lines can be difficult. were used. For example, a contaminated Although industry often wants to limit the food may have been used as an ingredient recall to the production lots implicated in food(s) that were not subsequently treated in illnesses, the conditions or extent of to destroy the contaminant, and additional contamination observed within the facility recalls may be necessary. An ingredient may warrant a more comprehensive recall. also may be indicated if a large number of Was an ingredient identified as a possible illnesses are not linked to the foods from one source of illness used in multiple food implicated facility. processes? Often, implicated lots will be Detailed information and sample forms for recalled while a hold is placed on other use by food establishments are included in products until their safety can be determined the “CIFOR Foodborne Illness Response through an environmental assessment and Guidelines for Owners, Operators and product sampling. Because recalls often Managers of Food Establishments” (7) expand as more contaminated products are 2020 | Guidelines for Foodborne Disease Outbreak Response 129
6.5 Outbreaks Involving Commercially Distributed Foods
Box 6.5. Steps to Improve the Effectiveness of Recall Measures and Industry Response
Conduct recall effectiveness checks to assess whether efforts to remove products from distribution channels work. Share distribution lists of recalled foods among government agencies and with the public Develop a list of verification or control measures to implement immediately when an outbreak- related or illness-related recall has been identified. Identify industry needs and develop guidance for • Interacting with public health or agriculture officials investigating an outbreak. Provide retailers and manufacturers with 24/7 contact numbers and emails for regulators at the local, state, and federal levels, including FDA and USDA’s Food Safety and Inspection Service (USDA-FSIS). • Providing timely notification of customers, appropriate government agencies, and the public of recalls involving particularly hazardous contaminants. • Mitigating the impact of an outbreak- related or illness-related recalls. Examples: clean out the display cases, follow destruction for recalled product, recommended practices for disposing of returned product. Develop guidance for communicating with the news media, including the preparation of talking points to answer inquiries. Have a plan for coordinating a news media telebriefing or video briefing, if needed. Identify a spokesperson. 6 Develop standard templates for press releases and social media messages for use during an outbreak that follow best practices for crisis and emergency risk communication (https://emergency.cdc.gov/cerc). PREVENTION CONTROL MEASURES AND
• Food regulators should consider ways the FDA the authority to order a responsible to immediately notify food facilities in firm to recall a human or animal food when their jurisdiction through text messaging, FDA determines that 1) there is a reasonable email, blast fax, or phone calls of recalls probability that the food is adulterated or associated with high severity hazards (e.g., misbranded and 2) consumption would cause botulism associated with under processed serious adverse health consequences or death canned foods) that have a reasonable to humans or animals. probability of still being in commercial • The agency/jurisdiction should monitor distribution. Identifying subcategories of to ensure the recall is effective in stopping facilities is highly recommended so notices illnesses and food is completely removed. can be targeted to specific facilities (e.g., Are illnesses continuing after the recall? notices of a seafood recall sent specifically If so, why? Is there another contaminated to seafood retail establishments). This product or lot number that has not been process should include food bank donation recalled? Was the product purchased after centers and other sites that might have the recall? If so, from where? Was the received food donations. consumer aware of the recall notice? • If any distributors or retailers refuse • Assessing recall effectiveness requires to remove the food, issuance of a close cooperation among local, state, public health warning and order to territorial, tribal, and federal agencies to require action might be necessary. The accomplish risk-based recall effectiveness appropriate agency for this action depends on checks across the distribution system. the type of food and etiologic agent. Passage For example: many large-volume retailers of the Food Safety Modernization Act gave 130 Council to Improve Foodborne Outbreak Response
6.5 Outbreaks Involving Commercially Distributed Foods
routinely sell product to smaller retailers that • Post-recall reporting by the food business may use cash for purchases. Participating or manufacturer. If a food business or in recall effectiveness checks can help local manufacturer recalls a product, it should and state agency staff maintain proficiency prepare interim and final reports about the in tracing contaminated products from the recall. The contents of these reports are source(s) throughout distribution chains. If used to determine the need for further recall the product is not immediately removed, actions. The reports should include copies determine why. of all notices distributed to the public and Did the manufacturer notify the through the distribution chain, as well as the distributor of the recall? following information: Did the distributor notify retailers of the Circumstances leading to the recall and recall? actions taken. Was the recall information clear and Extent of distribution of the suspected complete, including all lot numbers, use- food (documentation that can support by dates, bar codes? traceforward investigations). Did notifications occur but no action was Result of recall (percentage of suspected taken? food recovered). Was returned recalled product diverted Method of disposal or reprocessing of suspected food. 6 and sold elsewhere?
If the recall is not effective, notify Difficulties experienced in recall and appropriate state, federal, and actions taken to prevent recurrence of neighboring health and food-regulatory food-safety problems and any recall agencies. difficulties.
PREVENTION Issue a public advisory if needed.
6.6 Outbreak Wrap-up Activities
CONTROL MEASURES AND CONTROL MEASURES AND 6.6.1 Most outbreaks are considered over certain control measures have been effective in when two or more incubation periods of preventing additional illnesses. the etiologic agent have passed with no new cases. However, outbreak investigation The outbreak is truly over when the source and control activities should not cease when has been identified and controlled so it new cases of human illnesses cease to be cannot cause additional illnesses. To prevent identified. Clusters with low attack rates additional illnesses and future outbreaks, it is and cases from some sources might appear vital that investigation and control teams learn intermittently for years. This is especially why the outbreak occurred so effective controls common with agricultural products, such can be applied to address the contributing as romaine lettuce, where outbreaks have factors and root cause(s). Sharing lessons occurred each year, around the same time learned from each outbreak with the food of year, when products are harvested from industry in that sector or commodity group the same contaminated farms. PulseNet data can prevent future outbreaks in other locations. should be reviewed and monitored to make 2020 | Guidelines for Foodborne Disease Outbreak Response 131
6.6 Outbreak Wrap-up Activities
6.6.2 Restrictions put in place to prevent the same source. Another outbreak could additional illnesses may be removed recur the following year around the same when no further risk to the public exists, time if contaminated produce from certain such as when farms with unsafe water is the source. • Risk factors in the facility have been • Monitor the implicated foods or food eliminated and an effective system has been establishments to ensure agreed-to put in place to prevent their reoccurrence. changes in food-safety management systems • Ill food workers have recovered and are no are maintained and that no additional longer shedding pathogens (refer to the FDA contamination is occurring. Food Code for specific recommendations on Identify needed changes in writing, such restricted/excluded employees). as with a Risk Control Plan or Standard • Tests indicate no further contamination Operating Procedure. within the facility. Maintain communication with managers • Employees have been trained on proper of the implicated food establishment and methods to avoid the contributing factor(s) give them additional information if it of foodborne illness. becomes available. • Managerial controls are implemented and Increase the number of risk-based integrated within day-to-day operations and inspections at the implicated food 6 the facility’s operational culture (culture of establishment and sampling of implicated
food safety). foods, as needed, to monitor the firm’s PREVENTION CONTROL MEASURES AND development and implementation of 6.6.3 Monitoring plans should be preventive controls. developed to ensure the effective control Outdated, unsafe practices often are of the outbreak. difficult to change, and new practices might need to be reinforced multiple times before • Monitor the population at risk for signs they become routine. Consider customized and symptoms of the foodborne illness training to support the desired behavioral to ensure the outbreak has ended and change. Determine whether behavioral the source of illness has been eliminated. change has occurred long term. Consider Epidemiologists and communicable disease
requiring that the establishment or firm control staff should consider conducting hire a consultant to assist in developing active surveillance, working with healthcare safe systems and in monitoring if the providers to increase their identification facility has a history of unsafe practices. of associated cases, and collecting fecal samples from the population at risk. 6.6.4 Outbreak investigation and control Monitor the Whole Genome Sequence teams should routinely meet and review (WGS)– PulseNet database to assess whether all aspects of the investigation. Processes closely related cases have occurred in the that systematically review investigation and region or nationally. An outbreak at a control efforts after the response is over have food establishment may be caused by a two primary goals (Box 6.6): contaminated food ingredient or product that they received. Also monitor WGS-PulseNet 1. Improve the effectiveness of future over the next year for matching cases. Listeria, investigations and responses. Salmonella, and Shiga toxin–producing 2. Prevent recurrence at the facility or in Escherichia coli outbreaks often reoccur from similar types of food operations. 132 Council to Improve Foodborne Outbreak Response
6.6 Outbreak Wrap-up Activities
Box 6.6. Goals of Formal After-Action Meeting
Improve the effectiveness of future investigations and responses: • Clarify resource needs, structural changes, or training needs to improve future outbreak response. • Identify factors that compromised the investigations, and seek solutions. • Identify necessary changes to current investigation and control guidelines and development of new guidelines or protocols as required. • Discuss any legal issues that might have arisen and the need for new laws to strengthen response (Chapter 2). Prevent recurrence at this facility or in similar types of food operations: • Identify the contributing factors and environmental root causes of the outbreak and measures (preventive controls) to prevent additional outbreaks at this and other food establishments. • Determine whether others need to be notified of lessons learned from the investigation to prevent outbreaks elsewhere. • Identify the long-term and structural control measures, develop a plan for their implementation, and determine surveillance and follow-up needed to ensure an outbreak does not reoccur. Assess the effectiveness of outbreak control measures and difficulties in implementing them. Assess whether further scientific studies should be conducted. 6
Assessments of the effectiveness of the What went well? investigation and control efforts should What did not go well? maintain a balanced approach that identifies strengths to be built upon and areas of What resources were needed that were
PREVENTION improvement to be addressed. The complexity unavailable? of the review depends on the size and What will be done differently next time? complexity of the outbreak. For a small What follow-up is needed from root-cause outbreak associated with a single facility or analysis to ensure this does not happen event, a quick meeting and short written again (Action Plan: who will do what
CONTROL MEASURES AND CONTROL MEASURES AND summary may be sufficient. by when)? For a large outbreak involving multiple • After-action review meetings often agencies, a series of meetings resulting in a involve response team members, response formal after-action report is appropriate. partners, and sometimes stakeholders. These meetings are more formal, systematic, and Two types of meetings can be used as part of comprehensive and, because of the need to effective after-action review processes: coordinate schedules and information sharing, • Hot wash/debriefings involve investigation might occur 1–2 months after the response. and control team members to gather input Effective after-action review processes result within 1–2 weeks after the investigation’s from planning and the intentional dedication completion while it is fresh in responders’ of resources to support these meetings. Share minds. These are often less formal and written summaries of each meeting with single-agency in nature. Examples of typical attendees and interested response partners. agenda items include Lessons learned from outbreaks should be 2020 | Guidelines for Foodborne Disease Outbreak Response 133
6.6 Outbreak Wrap-up Activities communicated appropriately so they can and after-action reports are available at the promote improvement; even the best lessons CIFOR Clearinghouse (7). learned have minimal impact if they are not shared with relevant partners and stakeholders. 1. Given that reports, especially those for Link formal action items identified by the large outbreaks, are likely to be subject to process to the agency’s continuous process Freedom of Information Act (8) requests, improvement program(s) to ensure appropriate they should be written with public accountability for tracking and correction. disclosure in mind. The reports should not identify individuals or other protected If additional information becomes available in information unless necessary and legally the weeks or months after the outbreak and the defensible. Proper care in writing the report official after-action meeting, disseminate that will save time redacting information when information to the outbreak investigation and the report is released to the public. Some control team and appropriate external partners. jurisdictions allow or mandate the inclusion of identifying information, so review state 6.6.5 Prepare reports for all outbreaks. and local laws and policies. The report complexity depends on the size of the outbreak. For small outbreaks, a simple 2. Submit a final report of the outbreak to summary (following a template established by CDC’s National Outbreak Reporting the agency) should suffice. Use the report to System and National Environmental educate staff and share important investigation Assessment Reporting System databases 6 (9,10). FDA-funded Rapid Response Teams
findings with others. When combined with PREVENTION CONTROL MEASURES AND other reports, this information can help have uploaded after-action reports into identify trends across outbreaks that can be FoodSHIELD (11). useful in future investigations. Control of contributing factors without Use outbreak reports as an opportunity for addressing the root cause for their presence in continuous quality improvement. If all the the facility can result in a repetitive cycle of after-action reports cite the same areas for short-term correction followed by gradual loss improvement, then nothing is being corrected. of food-safety controls and outbreak recurrence. Outbreak investigation reports provide an Sharing the root causes of outbreaks enables a opportunity to document both lessons broad range of food-safety stakeholders (e.g., learned during the investigation and the agencies, food industries, academic institutions, investigation’s results. and consumers) to coordinate work within their respective spheres of influence to strengthen Well-conducted and documented outbreak food-safety systems worldwide. investigations guide prevention efforts by identifying foods at risk for contamination, 6.6.6 The outbreak investigation findings locations within food-supply chains where may indicate the need for future research. contamination is introduced, factors directly For example, investigators may determine that contributing to contamination, and the for certain pathogens in certain foods, standard root causes) control measures do not seem effective or routine handling practices and their role in The final report for a large outbreak should outbreaks are not completely understood. The be comprehensive, provide information by all food-safety or public health agency or research team participants, and be disseminated to all centers should consider such observation for participating organizations. Sample outbreak in-depth study. Regular review of reports of 134 Council to Improve Foodborne Outbreak Response
6.6 Outbreak Wrap-up Activities
foodborne illness outbreak investigations outbreaks or reduce the number of cases or can identify important trends and areas of severity of illness during an outbreak. undercontrolled risks. Questions raised by Trade associations, food-industry stakeholders and researchers include organizations, and national conferences • How common is this pathogen as identified often request presentations on outbreak to the subtyping level by WGS? investigations. These events provide an • Is there a recurring pattern every year opportunity to educate representatives of around the same time? the food industry, colleagues, and others about investigation procedures, outbreak • Is there a high baseline in this region of the management, preventive controls, and country that may indicate an ongoing source CIFOR. that needs to be identified and eliminated? 6.6.9 Information gained during an 6.6.7 If unusual findings characterized outbreak is used to identify the need for the outbreak (e.g., unusual exposure, new public health or regulatory policy at presence of a pathogen in a food where it the local, state, territorial, tribal, or federal had not previously been reported or by the level. Different inspection practices, source magnitude of the outbreak) or new methods controls, surveillance procedures, or recall were used in its investigation, disseminate process controls have been established on the the report more widely (e.g., through Epi-X, basis of well documented investigation reports.
6 MMWR, or other national forum; peer-
reviewed journals). Publish important lessons Ongoing and regular review of outbreak learned (such as new investigation methods that investigation reports, research, and industry proved particularly helpful, control measures practices identifies the need for new policy. that seemed particularly effective, actions taken FDA regularly updates the Food Code (3) to that seemed to shorten the outbreak) in an better address the leading foodborne illness
PREVENTION appropriate national forum. risk factors identified by epidemiologic outbreak data. For example, an analysis of 6.6.8 An outbreak can identify the need outbreaks by the Environmental Health for broad education of the public; the Specialist Network identified an association food-service, retail, food processing, between not having a manager certified in and agricultural industries; food-safety CONTROL MEASURES AND CONTROL MEASURES AND food safety and outbreaks (12). Similarly, FDA regulators; or healthcare providers. found an association between the presence of Public outreach, including public service certain foodborne illness risk factors and the announcements, can remind the public about lack of a certified manager (13). These findings food-preparation precautions. National led to changing the FDA Food Code to require training programs for food workers and the person in charge of most retail and food- managers are regularly revised to reflect service establishments, those posing more than current understanding of the root causes of a minimal foodborne illness risk, be a Certified foodborne illness. Food-safety management Food Protection Manager. systems increasingly hold managers accountable for ensuring that training of Consult other public health and environmental food workers is appropriate for assigned health agencies to determine whether job responsibilities. Healthcare providers concurrence exists on the need for new policy. might need continuing education focused on If so, present the issue to the appropriate diagnosing, treating, or reporting foodborne jurisdictional authority by using the diseases. Such actions can help prevent future appropriate policy development processes. 2020 | Guidelines for Foodborne Disease Outbreak Response 135
References
1 Colorado Department of Public Health and 7 CIFOR. Food Safety Clearinghouse. Environment, Colorado School of Public Health. https://cifor.us/clearinghouse Communications toolkit. http://www.ucdenver. 8 FOIA.gov. https://www.foia.gov edu/academics/colleges/PublicHealth/research/ centers/foodsafety/Documents/Media%20 9 Centers for Disease Control and Prevention. Communication%20toolkit-V3-Final.pdf National Outbreak Reporting System (NORS). https://www.cdc.gov/nors 2 CIFOR. Products. https://cifor.us/products/industry 10 Centers for Disease Control and Prevention. National 3 Food and Drug Administration. FDA Food Code. Environmental Assessment Reporting System https://www.fda.gov/food/guidanceregulation/ (NEARS). https://www.cdc.gov/nceh/ehs/nears retailfoodprotection/foodcode/default.htm 11 FoodSHIELD. https://www.foodshield.org 4 Food and Drug Administration. Resources for regulatory partners. https://www.fda.gov/federal- 12 Hedberg CW, Smith SJ, Kirkland E, Radke V, Jones state-local-tribal-and-territorial-officials/resources- TF, Selman CA, et al. Systematic environmental regulatory-partners evaluations to identify food safety differences between outbreak and nonoutbreak restaurants. J Food Prot. 5 U.S. Department of Agriculture., Food Safety and 2006;69:2697–702. Inspection Service. Resources for public health partners: foodborne illness investigation. 13 Cates SC, Muth MK, Karns SA, Penne MA, Stone https://www.fsis.usda.gov/wps/portal/fsis/topics/ CN, Harrison JE. Certified kitchen managers: do they recalls-and-public-health-alerts/audience-public- improve restaurant inspection outcomes. J Food Prot. health/resources-for 2009;72:384–91. 6 Food Safety Modernization Act. Pub. L. No. 111–353,
124 Stat. 3885 (2011). 6 PREVENTION CONTROL MEASURES AND
CHAPTER 7
Special Considerations for Multijurisdictional Outbreaks
CHAPTER SUMMARY POINTS
• A multijurisdictional outbreak of foodborne illness requires the resources
of more than one local, state, territorial, tribal, or federal public health or
food regulatory agency to detect, investigate, or control.
• Recognition of outbreaks with multistate exposures will continue to
increase with implementation of whole-genome sequencing in foodborne
illness surveillance.
• Special efforts may be needed to
Help agencies recognize when a multijurisdictional outbreak is occurring
and then identify and engage key partners in the investigation.
Improve communication and coordination among agencies at all levels
of government that are investigating multijurisdictional outbreaks.
Increase the speed and effectiveness of investigating and controlling
multijurisdictional outbreaks.
URLs in this chapter are valid as of August 28, 2019. 138 Council to Improve Foodborne Outbreak Response
7.0 Introduction
Multijurisdictional investigations range from organizations across jurisdictions increases, the different agencies and departments at a local need for special efforts to maintain effective level collaborating on a simple investigation communication and coordination increases as to a large multistate outbreak with the well. (See Chapter 5 for general approaches potential identification of imported foods. to investigating clusters and outbreaks of As the number of agencies and levels of foodborne illnesses.)
7.1 Categories and Frequency of Multijurisdictional Outbreaks
A multijurisdictional outbreak of foodborne genome sequencing (WGS), these investments illness requires the resources of more than one in foodborne disease surveillance have local, state, territorial, tribal, or federal public increased the number of outbreaks recognized health or food regulatory agency to detect, as multijurisdictional (Table 7.1). For example, investigate, or control the pathogen in question during 2006–2010, 1.7% of all foodborne (Box 7.1). For some, such as multistate outbreaks illness outbreaks reported to the Centers identified through PulseNet surveillance, the for Disease Control and Prevention (CDC) multijurisdictional nature of the outbreak National Outbreak Reporting System [NORS] may be readily apparent. For others, it may involved multistate exposures and many more emerge during the investigation. Special efforts affected residents of multiple states or counties may be needed to help agencies recognize a (2). During 2011–2016 the percentage of multijurisdictional outbreak and then to identify outbreaks with multistate exposures doubled to and engage key partners in the investigation. 3.4% (3). Overall, during 2009-2018, 27.1% of Escherichia coli O157:H7 outbreaks and 14.1% The passage of the Food Safety Modernization
7 of Salmonella outbreaks involved multistate Act (1) in 2011 gave new authorities to the exposures, discovered largely through PulseNet Food and Drug Administration (FDA) and (3). Thus, for these most important foodborne provided a mandate to enhance surveillance pathogens, the need for multijurisdictional and response capacity at local, state, territorial, coordination should be anticipated during the tribal, and federal levels. Combined with the earliest stages of an investigation. development and implementation of whole-
Box 7.1. Categories of Multijurisdictional Outbreaks
• Outbreaks affecting multiple local health jurisdictions (e.g., city, county, town) within the same state. • Outbreaks involving multiple states. • Outbreaks involving multiple countries.
SPECIAL CONSIDERATIONS FOR FOR SPECIAL CONSIDERATIONS • Outbreaks affecting multiple distinct agencies (e.g., public health, food regulatory, emergency management). MULTIJURISDICTIONAL OUTBREAKS MULTIJURISDICTIONAL • Outbreaks, regardless of jurisdiction, caused by highly pathogenic or unusual agents (e.g., Clostridium botulinum) that require specialized laboratory testing, investigation procedures, or treatment. • Outbreaks in which the suspected or implicated vehicle is a commercially distributed, processed, or ready-to-eat food contaminated before the point of service. • Outbreaks involving large numbers of cases that may require additional resources to investigate. • Outbreaks in which intentional contamination is suspected. 2020 | Guidelines for Foodborne Disease Outbreak Response 139
7.1 Categories and Frequency of Multijurisdictional Outbreaks
Table 7.1. Number of foodborne outbreaks with multistate exposure, multistate residency, multicounty exposure, and multicounty residency, by etiology, United States, 2009–2018 (3) MULTISTATE MULTICOUNTY RESIDENCY, RESIDENCY, ETIOLOGY NO. TOTAL MULTISTATE MULTICOUNTY SINGLE SINGLE AND AGENT OUTBREAKS EXPOSURE EXPOSURE STATE COUNTY EXPOSURE EXPOSURE
Confirmed Etiology 4,239 317 228 239 1,075
Escherichia coli 192 52 5 32 42 O157:H7 Salmonella 1,291 182 76 121 347 Clostridium 165 0 3 0 49 perfringens Staphylococcus 47 0 2 1 14 aureus Hepatitis A virus 27 2 2 4 7 Norovirus 1,532 3 89 22 437 Other 985 78 51 59 179
Suspected Etiology 1,962 5 101 18 385 7 MULTIJURISDICTIONAL OUTBREAKS SPECIAL CONSIDERATIONS FOR Unknown Etiology 2,184 2 101 36 357 Multiple Etiologies 146 1 6 3 36
TOTAL 8,531 325 436 296 1,853
Specifically related to multijurisdictional Coordinating offices for foodborne illness outbreaks, recent investments have been investigations in the three primary federal made to agencies include
• Improve coordination and data-sharing • CDC: Outbreak Response and Prevention between public health partners and Branch (Division of Foodborne, Waterborne, the public. and Environmental Diseases, National
• Increase state and local participation in Center for Emerging and Zoonotic national surveillance networks. Infectious Diseases). • Expand and integrate national • FDA: Coordinated Outbreak Response and surveillance systems. Evaluation Network (CORE). • Enhance laboratory and epidemiologic • U.S. Department of Agriculture’s Food methods for agent identification and Safety and Inspection Service (USDA-FSIS): outbreak detection and investigation. Applied Epidemiology Staff. 140 Council to Improve Foodborne Outbreak Response
7.2 Multijurisdictional Outbreak Detection
7.2.1 Multijurisdictional outbreaks may be potential multijurisdictional outbreak, a local detected at local, state, territorial, tribal, agency should ensure notification of the state or federal levels. Outbreaks detected at the health department and other local agencies, local level through investigations of consumer as appropriate, and provide subsequent complaints, individual cases, or case clusters of updates in accordance with state procedures reportable foodborne illnesses (Chapter 4) may to ensure coordination between epidemiology, identify common-source outbreaks or multiple environmental health, and the public subclusters of illnesses that implicate or suggest health laboratory. likely contamination of food before the point of service. Detection of multijurisdictional outbreaks at a state level requires notification of Detection of multijurisdictional outbreaks affected county and city health departments. at a state level may result from an increase CDC and state and federal food regulatory of sporadic infections with common subtype agencies need to be notified of subclusters characteristics identified, investigation of or linked common-source outbreaks. For subclusters of illnesses that identify a possible example, FDA has established its CORE association with multiple food service Network to respond to outbreaks. USDA- establishments, or the linking of multiple, FSIS has developed a template for including discrete common-source outbreaks by common their agency in foodborne illness outbreak agent, food, or water. response procedures (4). Notify USDA-FSIS of outbreaks potentially associated with USDA- Similarly, national increases of infections with FSIS-regulated products by sending an email common subtype characteristics identified; to [email protected] and to identification of subclusters of illnesses the appropriate regional contact in the USDA- associated with multiple restaurants or food FSIS Office of Enforcement, Investigation, 7 service establishments in multiple states; and and Audit (https://www.fsis.usda.gov/wps/
linkage of multiple, discrete common-source portal/informational/districtoffices#oiea). outbreaks in multiple states would lead to a multijurisdictional outbreak investigation. Detection of multijurisdictional outbreaks at a national level requires notification of Detection of a pathogen, such as Listeria appropriate state and federal food regulatory monocytogenes, Shiga toxin–producing E. coli, agencies and state health departments of an or Salmonella, from a food item that resulted increase in apparently sporadic infections, from testing by a federal or state food subclusters, or linked common-source outbreaks. regulatory agency would lead to a search for In these events, states typically notify local human illnesses caused by the same organism agencies of the outbreak and the need for their with common subtype characteristics. assistance in conducting the investigation. Of Multijurisdictional investigation of infections particular importance are requests to interview SPECIAL CONSIDERATIONS FOR FOR SPECIAL CONSIDERATIONS with common subtype characteristics would case-patients as soon as possible using a detailed be conducted to determine whether they were MULTIJURISDICTIONAL OUTBREAKS MULTIJURISDICTIONAL exposure questionnaire to obtain detailed food part of an outbreak. and environmental exposure histories, including product brand and retail source. 7.2.2 When findings indicate that multiple jurisdictions might be involved in an 7.2.3 Assemble and brief the outbreak investigation, additional communication and investigation control team. Open and coordination are needed (Table 7.2). communication between investigation team With initiation of an investigation of a members to plan, conduct, and evaluate 2020 | Guidelines for Foodborne Disease Outbreak Response 141
7.2 Multijurisdictional Outbreak Detection
Table 7.2. Multijurisdictional Outbreak Identification Methods and Required Notification steps, by Agency Level OUTBREAK IDENTIFICATION METHOD REQUIRED NOTIFICATION STEPS LOCAL LEVEL • Common-source outbreak identified with • Notify affected jurisdictions to request assistance cases among persons who reside in other local to contact and interview case-patients in other jurisdictions. jurisdictions. • Common-source outbreak identified with • Notify the affected jurisdiction immediately. exposures in another jurisdiction. • Notify appropriate state and federal • Common-source outbreak identified in one food regulatory agencies about probable jurisdiction, investigation implicates food item contaminated food vehicle, or subcluster. contaminated before the point of service. • Notify affected county and city health • Subcluster of illnesses associated with restaurants departments, state health department, and or food service establishments. Centers for Disease Control and Prevention (CDC).
STATE LEVEL • Statewide increase identified in infections with • Notify affected county and city health common subtype characteristics. departments and CDC. • Subclusters of illnesses associated with multiple • Notify appropriate state and federal food restaurants or food service establishments. regulatory agencies of subclusters or linked • Common-source outbreaks in multiple local common-source outbreaks. jurisdictions linked by common agent, food, or water. 7 FEDERAL LEVEL MULTIJURISDICTIONAL OUTBREAKS SPECIAL CONSIDERATIONS FOR • National increase identified in infections with • Notify appropriate state and federal food common subtype characteristics. regulatory agencies, and state health departments • Subclusters of illnesses associated with multiple of increase in infections, subclusters, or linked restaurants or food service establishments in common-source outbreaks. multiple states. • Notify CDC, affected state health departments, • Common-source outbreaks in multiple states and other state and federal food regulatory linked by common agent, food, or water. agencies. • Food item tested positive by federal or state food regulatory agency linked to apparently sporadic infections with common subtype characteristics. outbreak investigation activities is critical to the of these key partners. In addition, many health success of the investigation (Chapter 5). For departments have an incident command multijurisdictional investigations, the outbreak system (ICS) that guide outbreak response investigation and control team should include (Box 7.2). Historically, investigations of members from all agencies participating in the multijurisdictional foodborne illness outbreaks investigation (Chapter 3, Tables 3.1 and 3.2). have not required formal activation of ICS. Agency preparedness plans should be in place However, federal regulatory agencies use ICS to facilitate rapid identification and notification for their response to outbreak incidents. 142 Council to Improve Foodborne Outbreak Response
7.2 Multijurisdictional Outbreak Detection
Box 7.2. Use of Incident Command Systems An incident command system (ICS) is the nationally recognized way that diverse individuals, agencies, and the private sector plan to work together to command, coordinate, and communicate during emergencies. Agencies responding to a public health emergency or foodborne outbreak can use ICS principles to help manage responses. ICS principles provide the flexibility needed to manage a wide range of foodborne illness outbreak responses, including single agency and multiagency outbreak investigation and control teams. ICS provides for internal communications among primary event responders, public information officers, and security/safety officers and for external liaison with various organizations. Key features for foodborne outbreak investigation and control teams include the following: • Standardized but flexible organizational structure. • Clearly defined and standardized roles and responsibilities. • Formal and systematic planning approach. • Coordinated response team, stakeholder, and public communications. • Formal mechanisms for managing transitions from routine to nonroutine responses by expanding and contracting response team structure and resources as needed. These features provide a predictable framework that can bring order to potentially chaotic situations when standard agency operating procedures and routine chain of command are inadequate to address the needs of an incident.
Because outbreak investigation staff may environmental health specialists, laboratorians, be physically located in different agencies and food regulators—need to be familiar with in several different cities or states, briefings and follow relevant state and federal laws, 7
may need to be conducted by teleconference terms of any memorandum of understanding or webinar. All members of the of the between agencies, and data-handling practices. investigation team—epidemiologists,
7.3 Identifying and Investigating Subclusters
Subclusters are groups of cases within a larger Cyclospora outbreaks, where no subtyping of the defined cluster for which exposure to the same outbreak strain characteristics was possible. individual points of service, such as a restaurant, cafeteria, grocery store, or institution, is In multijurisdictional investigations, make identified. Subcluster investigations provide an special efforts to identify potential subclusters SPECIAL CONSIDERATIONS FOR FOR SPECIAL CONSIDERATIONS invaluable opportunity to solve an outbreak across the geographic distribution of outbreak cases and to prioritize the coordination MULTIJURISDICTIONAL OUTBREAKS MULTIJURISDICTIONAL because the outbreak vehicle was most likely served by the common establishment (Chapter of subcluster investigations and tracing of 5). Although subclusters have traditionally common food exposures associated with the been identified within clusters of cases subclusters. If not previously established, defined by a common serotype, pulsed-field a coordinating office (or individual) for gel electrophoresis pattern, or closely related subcluster investigations should be empowered genomic sequence, successful subcluster to prioritize collection, organization, and investigations also have been conducted during dissemination of subcluster data. 2020 | Guidelines for Foodborne Disease Outbreak Response 143
7.4 Coordinating Multijurisdictional Investigations
Coordinating a multijurisdictional investigation CDC if no individual state is prepared to might require establishment of a coordinating do so. In multistate investigations led by office to collect, organize, and disseminate data an individual state, CDC should support from the investigation. Depending on the scope the investigation in coordination with the and nature of the multijurisdictional event, lead agency. the coordinating office might be located at a • Investigations of the food contamination local or state public health or food regulatory phase should be coordinated within food agency or at CDC, FDA, or FSIS. regulatory agencies. In addition to food Several principles guide decision about where regulatory agencies’ greater expertise to locate the coordinating office for a given and experience with these investigations, multijurisdictional investigation. The primary rules governing the collection of product goal is to avoid interagency conflict about manufacturing and distribution information coordination that might distract from prompt might dictate that authorized food regulatory conduct of the investigation and to present agencies not share that information with unified, consistent messages to the public. outbreak investigators in other agencies.
• Outbreaks are most efficiently investigated 7.4.1 Outbreak investigations progress as close to the source as possible. In general, through phases of activity, and leadership investigations should be coordinated at the of the investigation should reflect the level at which the outbreak originally was focus of the investigation at the time. detected and investigated. This is likely to be Investigations initiated at a local level are where most relevant investigation materials handled in accordance with routine policies will reside, which can facilitate organization and procedures under local agency leadership and analysis of data. An outbreak involving unless otherwise specified by state procedures. 7 several local health agencies might best be The level of state involvement depends on coordinated by a lead local agency. Similarly, local or state protocols. MULTIJURISDICTIONAL OUTBREAKS SPECIAL CONSIDERATIONS FOR investigation of a multistate outbreak with During investigations that require active most cases in one or a few adjacent states participation from multiple local agencies might best be coordinated by a lead state and state agencies, a state agency needs agency. Investigations of outbreaks of more to coordinate among the epidemiology, widely dispersed cases identified through environmental health, and laboratory pathogen-specific surveillance might best be components of the investigation at the state coordinated by CDC. level and ensure that state epidemiology, • The coordinating office must have sufficient environmental health, and laboratory resources, expertise, and legal authority programs communicate and coordinate to collect, organize, and disseminate data activities with counterparts at the local and from the investigation. Local agencies might federal levels. Typically, epidemiologic efforts not have sufficient resources to effectively to characterize the outbreak by person, place, coordinate a multijurisdictional investigation, and time dominate the early stages of an or state rules might assign jurisdiction investigation. Efforts to identify the mode over multicounty investigations to the state of transmission and food vehicle begin to health department. In these situations, the incorporate environmental health specialists coordinating office should be located at the and food regulators. Determining contributing state level. In multistate investigations, the factors and environmental antecedents, coordinating office should be located at conducting regulatory tracebacks, and 144 Council to Improve Foodborne Outbreak Response
7.4 Coordinating Multijurisdictional Investigations
implementing control measures move the sharing, they also might require federal agency investigation into the food regulatory realm. leadership, depending on the capabilities and Transition of leadership within the outbreak willingness of the states involved. control team should be planned in advance by consensus and communicated to the Sharing of information between public entire team. health and food regulatory agencies is critical to the effectiveness of multijurisdictional During investigations of national significance, investigations. Ensuring the facilitation of federal agencies need to coordinate the rapid and open information sharing can epidemiology, environmental health, and greatly enhance the efficiency and effectiveness laboratory components of the investigation of multijurisdictional investigations. Because at the federal level and ensure that federal these activities build on each other, establishing epidemiology, environmental health, and information-sharing protocols during the laboratory programs are communicating and earliest stages of the investigation is critical. coordinating activities with their counterparts State, local, and federal public health officials at the state and local levels. should ensure that their agencies have the legal authorities needed to share information and 7.4.2 Communication and coordination that their professional staff understand those plans should reflect the focus of the authorities (Chapter 2). Unless state and local investigation at the time. Investigations public health officials have been commissioned initiated at a local level require information to receive confidential information from FDA, sharing and coordination among multiple they might need to work directly with the local agencies under local agency leadership establishment implicated in the outbreak to unless otherwise specified by state procedures. obtain those data (Chapters 2 and 3). FDA’s The state receives information and provides Office of Partnerships has a commissioning 7 consultation. and credentialing program that enables
the sharing of commercial confidential When the resources of one or more local information to Commissioned Officials and/ jurisdictions cannot adequately respond to or signatories of Confidentiality Agreements events by following routine procedures, the (Chapter 2.3.4). state should provide response coordination, consultation, and information sharing. On Identifying the source of a multijurisdictional the basis of established procedures, emergency outbreak is a collaborative process among management systems, possibly including ICS, local, state, and federal agencies and industry. might be activated at the local—or possibly Individual food companies and trade state—level. Federal agencies are notified associations should be engaged early on to help and involved depending on product type with the investigation. Industry collaborators and distribution. might be able to provide important SPECIAL CONSIDERATIONS FOR FOR SPECIAL CONSIDERATIONS information about food product identities, Multistate outbreaks and outbreaks associated
MULTIJURISDICTIONAL OUTBREAKS MULTIJURISDICTIONAL formulations, and distribution patterns that with regionally or nationally distributed can improve hypothesis generation and assist food products involve a transition from state in informational tracebacks to aid hypothesis to national significance. These outbreaks testing. Early engagement of industry also can might require regional or national resources. facilitate control measures by enabling affected Although they require active participation industries to implement orderly product from multiple local agencies and state response withdrawal or recall procedures. coordination, consultation, and information 2020 | Guidelines for Foodborne Disease Outbreak Response 145
7.4 Coordinating Multijurisdictional Investigations
Release of public information about the Compiling data from case-patient interviews in outbreak should be coordinated with the lead a central location where they can be reviewed investigating agency when feasible. Although in aggregate will facilitate recognition of the public and news media are not aware suspected food items, particularly when an of most outbreak investigations, the results unusual or new food item may be involved. of investigations are public information. In addition, responding to media attention is 7.4.4 Coordinate informational tracebacks important to address public concerns about to identify suspected vehicles and guide the outbreak. Although individual agencies sampling activities. Tracing the source of participating in the investigation might be food items or ingredients through distribution obligated to provide the perspective of their to source of production can be critical to own leadership when responding to media identifying epidemiologic links among cases or inquiries, a coordinated communications plan ruling them out (Chapter 5). can help provide a consistent, unified message Multijurisdictional investigations increase the about the progress of the investigation, the importance of product tracing because they source of the outbreak, or any prevention can triangulate among multiple distribution activities that the public can do to protect itself. pathways that may link geographically Coordinating communications with the media dispersed cases. Thus, coordinating traceback is particularly important when media attention investigation across the outbreak should is needed for public action to avoid exposure be prioritized. The coordinating office (or to a specific contamination source, such as a individual) for traceback investigations recalled food product. should be empowered to prioritize collection, 7.4.3 Use standardized data-collection organization, and dissemination of traceback data to determine whether it converges on forms and centralize compilation of data 7 from case-patient interviews. The National a common source or supplier. Because this MULTIJURISDICTIONAL OUTBREAKS SPECIAL CONSIDERATIONS FOR Hypothesis Generating Questionnaire information can be critical to identifying (NHGQ) can be used to collect information on epidemiologic links, results should be shared, a broad range of food and nonfood exposures as they develop, with epidemiologists, which (http://cifor.us/downloads/clearinghouse/ will enable epidemiologists to have meaningful NHGQ_v2_OMB0920_0997.pdf) during input in exposure selection and interpretation the early stages of an outbreak investigation to help guide future directions for the (Chapter 5). As hypotheses develop and are investigation (5). refined, an outbreak-specific questionnaire Identification of a common source or supplier can be developed to systematically collect data can facilitate sampling activities to confirm from the various states or local jurisdictions contamination of the product and the contributing to the investigation. Collecting potential source of the contamination. detailed information on both the food item and its source as early in the process as possible is key to identifying the source of an outbreak. Thus, ensuring that all agencies participating in the investigation use the same outbreak- specific questionnaire is important. In addition, if sufficient staff are not available to rapidly conduct interviews, agencies should request external assistance to conduct interviews. 146 Council to Improve Foodborne Outbreak Response
7.5 Multijurisdictional Outbreak Investigation After-Action Reports and Reporting to NORS
The lead agency(ies) coordinating the report before it is more widely distributed. investigation should hold a conference call The lead agency(ies) should review after-action 1–3 months after the initial investigation reports periodically to determine whether ends to review lessons learned and to update common problems regarding investigation, participants about findings, conclusions, response, or root cause are recurring over time; and actions taken (Chapter 6). After the this review can help with an agency’s quality conference call, they should prepare an after- improvement and prevention efforts. action report to summarize the effectiveness of communication and coordination among Individual states should report all jurisdictions, identify specific gaps or problems multijurisdictional investigations to NORS. that arose during the investigation, and The lead investigating agency, whether a communicate lessons learned regarding root state or local health department or CDC, cause and contributing factors. should collate information from all involved jurisdictions and submit one outbreak report All participating agencies should have the to NORS (https://www.cdc.gov/nors/ opportunity to review and comment on the downloads/appendix-b.pdf).
References
1 Food Safety Modernization Act. Pub. L. No. 5 Smith K, Miller B, Vierk K, Williams I, Hedberg 111–353, 124 Stat. 3885 (2011). C. Product tracing in epidemiologic investigations 2 CIFOR. Guidelines for foodborne disease outbreak of outbreaks due to commercially distributed food items—utility, application, and considerations.
7 response. Second edition. https://cifor.us/ http://mnfoodsafetycoe.umn.edu/wp-content/
products/guidelines uploads/2015/10/Product-Tracing-in- 3 Centers for Disease Control and Prevention. Epidemiologic-Investigations.pdf National Outbreak Reporting System (NORS). https://wwwn.cdc.gov/norsdashboard 4 U.S. Department of Agriculture, Food Safety and Inspection Service. https://www.fsis.usda.gov/ OutbreakProcedures SPECIAL CONSIDERATIONS FOR FOR SPECIAL CONSIDERATIONS MULTIJURISDICTIONAL OUTBREAKS MULTIJURISDICTIONAL CHAPTER 8
Performance Metrics for Foodborne Illness Programs
CHAPTER SUMMARY POINTS
• Evaluating the timeliness and effectiveness of surveillance, investigation,
and control of foodborne illnesses and outbreaks is critical to improving
these activities at the local, state, territorial, tribal, and national levels.
• Numerous programs involved in foodborne illness outbreak detection,
investigation, and response have developed and routinely use metrics to
assess their work and measure performance.
• The aggregation of data at state, regional, or national levels could provide
a comprehensive overview of foodborne illness surveillance and control
programs, rather than a system for ranking them.
URLs and email addresses in this chapter are valid as of July 9, 2019. 148 Council to Improve Foodborne Outbreak Response
8.0 Introduction
Surveillance and investigation of foodborne or initiative in which a jurisdiction is illnesses and outbreaks are essential for participating. Quality improvement literature controlling and preventing foodborne illnesses. and programmatic experience has shown that Multiple entities—more than 3,000 local health departments; 50 state and numerous • The most meaningful performance metrics territorial and tribal health departments; and are tied directly to a program’s activities; several federal agencies—interact in a complex • Metrics promote a common understanding system covering surveillance for, detection of, of the key elements of foodborne illness and response to enteric and other foodborne surveillance and control activities across illnesses and outbreaks. local, state, territorial, tribal, and federal public health agencies; Evaluating the timeliness and effectiveness of surveillance, investigation, and control of • Using a framework (like the one presented foodborne illnesses and outbreaks is critical to in this chapter) can save time and resources improving these activities at all levels. Since by describing what types of activities could the publication of the Second Edition of the be measured, but programs or jurisdictions CIFOR Guidelines, the use of performance will need to determine how to measure metrics by various food-safety programs components in a way that is meaningful for and agencies has increased. Performance their purposes; metrics enable a program to assess processes • Process-based metrics are often easier to and identify opportunities to improve design and implement, whereas multifactorial processes. This Third Edition of the CIFOR outcome metrics can be more challenging; Guidelines draws heavily on the experiences • Evaluating performance metric data over of other programs in developing and using time can enable programs or jurisdictions to performance metrics. evaluate the impact of changes in practice Performance metrics are commonly associated and target additional activities for ongoing with quality improvement initiatives, including improvement efforts; and accreditation and capacity building. The • Metrics can elucidate successes and types of performance metrics, and how 8 identify gaps in the detection, investigation, they are developed and implemented, are prevention, and control of sporadic often determined by the type of program foodborne illnesses and outbreaks.
8.1 Purpose and Intended Use
Numerous programs involved in foodborne The metrics are a curated list of the most illness outbreak detection, investigation, and important metrics that programs can use to response have developed and use metrics for assess their work and measure performance routine program evaluation (Table 8.1). The in activities related to surveillance, combined experience of these programs was investigation, and control of foodborne
PERFORMANCE METRICS FOR PERFORMANCE METRICS FOR used to develop the performance metrics in illnesses and outbreaks. Table 8.2. URLs for each program’s FOODBORNE ILLNESS PROGRAMS complete list of metrics are available on Foodborne illness and outbreak investigations the CIFOR website. are multidisciplinary, but different agencies use staff in varying disciplines or areas of 2020 | Guidelines for Foodborne Disease Outbreak Response 149
8.1 Purpose and Intended Use expertise to perform surveillance, investigation, compare their data to the summary data from and control activities. Thus, categories other programs or agencies to determine of environmental health, laboratory, where improvements might be realistic. and epidemiology are used solely for the Neither target ranges nor participant data organization of the metrics, not to suggest are intended to be used as scorecards or which staff should perform the specific duties performance standards. Defining the level of within an agency. In other words, not every performance expected from foodborne illness metric applies to every agency; for example, and outbreak surveillance, investigation, and some laboratory metrics may not be relevant to control programs exceeds the scope of these local public health agencies. Guidelines. The aggregation of data at state, regional, or national levels could provide a Users can evaluate their performance metric comprehensive overview of foodborne illness data over multiple time points, when those surveillance and control programs, rather than data are available. Additionally, users can a system for ranking them.
Table 8.1. Programs with Performance Metrics HOST AGENCY PROGRAM ABOUT THE PROGRAM Centers for Foodborne FoodCORE centers collaborate to develop new and better Disease Control Diseases Centers for methods to detect, investigate, respond to, and control multistate and Prevention Outbreak Response outbreaks of foodborne illness. They focus primarily on outbreaks (CDC) Enhancement caused by bacteria, including Salmonella, Shiga toxin–producing (FoodCORE) Escherichia coli (STEC), and Listeria. CDC OutbreakNet OutbreakNet Enhanced supports local and state health Enhanced departments to improve their capacity to detect, investigate, control, and respond to enteric illness outbreaks. OutbreakNet Enhanced sites collaborate with each other and CDC to share experiences and insights that help improve enteric illness outbreak response. OutbreakNet Enhanced activities focus on improving detection and rapid interviewing Salmonella, STEC, and Listeria case-patients and of persons with enteric illness 8
caused by pathogens that demonstrate antimicrobial resistance. FOODBORNE ILLNESS PROGRAMS PERFORMANCE METRICS FOR CDC National NEARS is a Web-based surveillance system that local and state Environmental health departments use to report environmental assessment Assessment data from foodborne illness outbreak investigations. NEARS Reporting System helps the national food-safety system by providing critical data (NEARS) from environmental assessments to prevent and reduce future outbreaks. CDC National Outbreak NORS is a Web-based platform launched in 2009. It is used by Reporting System local, state, and territorial health departments to report to CDC (NORS) all waterborne and foodborne illness outbreaks and enteric disease outbreaks transmitted by contact with environmental sources, infected persons or animals, or unknown modes. Food and Drug Rapid Response RRTs are multiagency, multidisciplinary teams that operate using Administration Teams (RRTs) Incident Command System/National Incident Management (FDA) System principles and a Unified Command structure to respond to human and animal food emergencies. RRTs are housed in food-regulatory agencies. 150 Council to Improve Foodborne Outbreak Response
8.1 Purpose and Intended Use
Table 8.1. Programs with Performance Metrics HOST AGENCY PROGRAM ABOUT THE PROGRAM FDA Voluntary National The Retail Program Standards define what constitutes a highly Retail Food effective and responsive program for regulating food-service Regulatory Program and retail food establishments. The Retail Program Standards Standards (Retail are intended to reinforce proper sanitation (good retail practices) Program Standards) and operational and environmental prerequisite programs while encouraging regulatory agencies and industry to focus on the factors that cause and contribute to foodborne illness, with the ultimate goal of reducing the occurrence of those factors. FDA Manufactured Foods The MFRPS are a critical component in establishing the national Regulatory Program Integrated Food Safety System. The goal of the MFRPS is to Standards (MFRPS) implement a nationally integrated, risk-based, food-safety system focused on protecting public health. The MFRPS establish a uniform basis for measuring and improving the performance of prevention, intervention, and response activities of manufactured food-regulatory programs. Development and implementation of the standards help state and federal programs better direct their regulatory activities toward reducing foodborne illness. U.S. Department Public Health The mission of FSIS is to protect the public’s health by ensuring of Agriculture– Indicators (from FSIS the safety of meat, poultry, and processed egg products. FSIS Food Safety and 2017–2021 Strategic has developed plans and resources to strengthen collaborative Inspection Service Plan) relationships with outbreak investigation partners. (USDA-FSIS)
8.2 Performance Metrics
The remainder of this chapter focuses programs. The original source metrics also 8 on Table 8.2, which includes 21 metrics may provide additional instructions, summary organized by discipline: environmental health, data from implementation of the metrics, and epidemiology, and laboratory. As noted above, examples of how the metrics have been used to the disciplines listed are for organizational guide planning and evaluation activities. purposes, not to suggest which staff should conduct certain portions of outbreak Agencies that frequently use metrics (Table 8.1) investigations. Within the epidemiology have extensive metrics but do not capture section, metrics are grouped by investigations every component of foodborne illness typically initiated from laboratory surveillance surveillance and control programs. Table data and investigations typically initiated from 8.3 presents additional metrics that are not complaint data (see Chapter 4). currently available from the referenced programs but may be valuable for agencies PERFORMANCE METRICS FOR PERFORMANCE METRICS FOR Details on calculating a particular metric are to examine. Because these metrics are not available on the websites of the programs that routinely collected by programs, users may FOODBORNE ILLNESS PROGRAMS produced the metrics, as are other metrics from need to create standardized definitions to these groups that might be relevant to their calculate the metrics. 2020 | Guidelines for Foodborne Disease Outbreak Response 151
8.2 Performance Metrics
Table 8.2. Foodborne Illness Performance Metrics from Existing Programs CATEGORY PERFORMANCE METRIC SOURCE OF METRIC Environmental The program maintains logs or databases for all Voluntary National Retail Food health complaint or referral reports from other sources Regulatory Program Standards, https:// alleging food-related illness, food-related injury, www.fda.gov/Food/GuidanceRegulation/ or unintentional food contamination. The final RetailFoodProtection/ProgramStandards/ disposition for each complaint is recorded in the ucm245409.htm database or log and is filed in, or linked to, the establishment record for retrieval purposes.
Percentage of outbreak investigations that National Environmental Assessment included an environmental assessment. Reporting System (NEARS), https://www. cdc.gov/nceh/ehs/nears/resources.htm
Percentage of outbreak investigations that NEARS, https://www.cdc.gov/nceh/ehs/ identified a contributing factor. nears/resources.htm
Average number of days between date the NEARS, https://www.cdc.gov/nceh/ehs/ outbreak establishment was identified for an nears/resources.htm environmental assessment and date of the establishment observation.
Percentage of traceback investigations that Rapid Response Teams successfully result in identification of an (RRTs), https://www.fda.gov/ implicated food. ForFederalStateandLocalOfficials/ ProgramsInitiatives/ucm475021. htm#Manual
Percentage of outbreaks reported to NEARS. NEARS, https://www.cdc.gov/nceh/ehs/ nears/resources.htm
Epidemiology Percentage of confirmed cases with exposure Foodborne Diseases Centers for 8
history obtained for Salmonella, Shiga toxin– Outbreak Response Enhancement FOODBORNE ILLNESS PROGRAMS PERFORMANCE METRICS FOR producing Escherichia coli (STEC), and Listeria. (FoodCORE), https://www.cdc.gov/ foodcore/metrics/ssl-metrics.html
OutbreakNet Enhanced (OBNE), https://www.cdc.gov/foodsafety/ outbreaknetenhanced/metrics.html
Time from case report to first interview attempt FoodCORE, https://www.cdc.gov/ for Salmonella, STEC, and Listeria cases. foodcore/metrics/ssl-metrics.html
OBNE, https://www.cdc.gov/foodsafety/ outbreaknetenhanced/metrics.html
Number and percentage of Salmonella, STEC, FoodCORE, https://www.cdc.gov/ and Listeria investigations with supplemental or foodcore/metrics/ssl-metrics.html targeted interviewing of case-patients. 152 Council to Improve Foodborne Outbreak Response
8.2 Performance Metrics
Table 8.2. Foodborne Illness Performance Metrics from Existing Programs CATEGORY PERFORMANCE METRIC SOURCE OF METRIC Epidemiology Number and percentage of Salmonella, STEC, FoodCORE, https://www.cdc.gov/ and Listeria investigations for which an analytic foodcore/metrics/ssl-metrics.html epidemiologic study was conducted. OBNE, https://www.cdc.gov/foodsafety/ outbreaknetenhanced/metrics.html Number and percentage of Salmonella, STEC, FoodCORE, https://www.cdc.gov/ and Listeria investigations with suspected foodcore/metrics/ssl-metrics.html vehicle/source identified. OBNE, https://www.cdc.gov/foodsafety/ Number and percentage of Salmonella, STEC, outbreaknetenhanced/metrics.html and Listeria investigations with confirmed vehicle/source identified. Number and percentage of all investigations FoodCORE, https://www.cdc.gov/ with clinical specimens collected and submitted foodcore/metrics/nou-metrics.html to any laboratory (public health or clinical). Number and percentage of foodborne or point- FoodCORE, https://www.cdc.gov/ source investigations with suspected vehicle/ foodcore/metrics/nou-metrics.html source identified.
Number and percentage of foodborne or point- source investigations with confirmed vehicle/ source identified. Number and percentage of outbreaks for which FoodCORE, https://www.cdc.gov/ National Outbreak Reporting System form was foodcore/metrics/ssl-metrics.html completed. OBNE, https://www.cdc.gov/foodsafety/ outbreaknetenhanced/metrics.html
8 Laboratory Time from isolation/isolate-yielding Salmonella, FoodCORE, https://www.cdc.gov/ STEC, or Listeria specimen collection to receipt foodcore/metrics/ssl-metrics.html at public health laboratory. Time from Salmonella or STEC isolate receipt (or FoodCORE, https://www.cdc.gov/ recovery) at public health laboratory to serotype foodcore/metrics/ssl-metrics.html result (not applicable for Listeria). Percentage of primary Salmonella, STEC, and FoodCORE, https://www.cdc.gov/ Listeria isolates with whole genome sequencing foodcore/metrics/ssl-metrics.html (WGS)* results. OBNE, https://www.cdc.gov/foodsafety/ outbreaknetenhanced/metrics.html Time from Salmonella, STEC, and Listeria isolate FoodCORE, https://www.cdc.gov/ receipt (or recovery) at public health laboratory foodcore/metrics/ssl-metrics.html PERFORMANCE METRICS FOR PERFORMANCE METRICS FOR to WGS* upload to PulseNet. OBNE, https://www.cdc.gov/foodsafety/ FOODBORNE ILLNESS PROGRAMS outbreaknetenhanced/metrics.html 2020 | Guidelines for Foodborne Disease Outbreak Response 153
8.2 Performance Metrics
Table 8.2. Foodborne Illness Performance Metrics from Existing Programs CATEGORY PERFORMANCE METRIC SOURCE OF METRIC Laboratory Time from Salmonella, STEC, and Listeria isolate FoodCORE, https://www.cdc.gov/ receipt (or recovery) at public health laboratory foodcore/metrics/ssl-metrics.html to sharing of WGS with national database. OBNE, https://www.cdc.gov/foodsafety/ outbreaknetenhanced/metrics.html *PFGE and WGS data will be compiled through 2019. Starting with 2020 data, only WGS will be measured.
Table 8.3. Additional Performance Metrics to Assess Response Effectiveness CATEGORY PERFORMANCE METRIC Environmental Program maintenance of complaint data in an electronic manner that can be queried. health Number of complaints received and rate of complaints per 100,000 population in the jurisdiction.
Number of outbreaks detected from complaints and rate of outbreaks per 1,000 complaints. Percentage of investigations reported to federal regulatory agencies within 72 hours after the suspected vehicle is identified. Median number of days from initiation of investigations to implementation of control measures Epidemiology Median number of days from initiation of Salmonella, Shiga toxin–producing Escherichia coli (STEC), and Listeria investigations to identification of source Foodborne illness outbreak rate: number of foodborne outbreaks reported (all agents) per 1,000,000 population. 8 Number of foodborne outbreaks reported (Salmonella, STEC, and Listeria) per 1,000 cases FOODBORNE ILLNESS PROGRAMS PERFORMANCE METRICS FOR Percentage of outbreaks for which etiology is identified. Laboratory Number and percentage of Salmonella, STEC, and Listeria isolates/clinical specimens submitted to the public health laboratory from cases diagnosed by culture-independent diagnostic testing at the clinical laboratory. Percentage recovery of Salmonella and STEC isolates from culture-independent diagnostic test positive specimens received at the public Health Laboratory.