A Multistate Outbreak of E Coli O157: H7 Infections Linked to Soy Nut Butter Rashida Hassan, MSPH,a,b Sharon Seelman, MS, MBA,c Vi Peralta, MPH,d,k Hillary Booth, MPH,e Mackenzie Tewell, MA, MPH, CPH,f Beth Melius, RN, MN, MPH,g Brooke Whitney, PhD,c Rosemary Sexton, BS,c Asha Dwarka, BS,c Duc Vugia, MD, MPH,d,k Jeff Vidanes, BS,d,k David Kiang, PhD,d,k Elysia Gonzales, RN, MPH,h Natasha Dowell, MPH,a,i Samantha M. Olson, MPH,a,j Lori M. Gladney, MS,a Michael A. Jhung, MD,a Karen P. Neil, MD, MSPHa BACKGROUND: In 2017, we conducted a multistate investigation to determine the source of an abstract outbreak of Shiga toxin-producing Escherichia coli (STEC) O157:H7 infections, which occurred primarily in children. METHODS: We defined a case as infection with an outbreak strain of STEC O157:H7 with illness onset between January 1, 2017, and April 30, 2017. Case patients were interviewed to identify common exposures. Traceback and facility investigations were conducted; food samples were tested for STEC. RESULTS: We identified 32 cases from 12 states. Twenty-six (81%) cases occurred in children ,18 years old; 8 children developed hemolytic uremic syndrome. Twenty-five (78%) case patients ate the same brand of soy nut butter or attended facilities that served it. We identified 3 illness subclusters, including a child care center where person-to-person transmission may have occurred. Testing isolated an outbreak strain from 11 soy nut butter samples. Investigations identified violations of good manufacturing practices at the soy nut butter manufacturing facility with opportunities for product contamination, although the specific route of contamination was undetermined. CONCLUSIONS: This investigation identified soy nut butter as the source of a multistate outbreak of STEC infections affecting mainly children. The ensuing recall of all soy nut butter products the facility manufactured, totaling .1.2 million lb, likely prevented additional illnesses. Prompt diagnosis of STEC infections and appropriate specimen collection aids in outbreak detection. Child care providers should follow appropriate hygiene practices to prevent secondary spread of enteric illness in child care settings. Firms should manufacture ready-to- eat foods in a manner that minimizes the risk of contamination. ’ aCenters for Disease Control and Prevention, Atlanta, Georgia; bCaitta, Inc, Herndon, Virginia; cUS Food and Drug WHAT S KNOWN ON THIS SUBJECT: Shiga toxin-producing Administration, College Park, Maryland; dCalifornia Department of Public Health, Sacramento, California; eOregon Escherichia coli (STEC) O157 causes ∼63 000 illnesses Health Authority, Portland, Oregon; fArizona Department of Health Services, Phoenix, Arizona; gWashington State annually in the United States. The highest incidence is among Department of Health, Shoreline, Washington; hPublic Health–Seattle and King County, Seattle, Washington; iEagle young children, who are at higher risk of severe infection. Medical Services, Huntsville, Alabama; jG2S Corporation, San Antonio, Texas; and kCalifornia Department of Public Foodborne STEC outbreaks are often associated with beef and Health, Richmond, California leafy greens. The findings and conclusions in this report are those of the authors and do not necessarily WHAT THIS STUDY ADDS: We identified soy nut butter as the represent the official position of the US Centers for Disease Control and Prevention. source of a multistate outbreak of STEC infections affecting Ms Hassan developed the data collection instruments, coordinated the data collection, conducted mainly children. This outbreak highlights the risk of STEC the analysis, and drafted and revised the manuscript; Dr Neil reviewed and revised data infection among young children and the critical role health collection instruments, supervised the coordination of data collection and analysis, and care providers play in outbreak detection. critically reviewed and revised the manuscript; Dr Jhung supervised the coordination of data collection and analysis and critically reviewed and revised the manuscript; Ms Peralta, Ms Booth, To cite: Hassan R, Seelman S, Peralta V, et al. A Multistate Ms Tewell, Ms Melius, Ms Gonzales, and Dr Vugia reviewed and revised data collection instruments, Outbreak of E Coli O157:H7 Infections Linked to Soy Nut collected and interpreted epidemiological data, coordinated product sampling, and critically Butter. Pediatrics. 2019;144(4):e20183978 (Continued) Downloaded from www.aappublications.org/news by guest on September 28, 2021 PEDIATRICS Volume 144, number 4, October 2019:e20183978 ARTICLE Shiga toxin-producing Escherichia coli In this article, we report findings from on the basis of whole-genome (STEC) O157 is an important cause of a rapid and collaborative sequencing (WGS) showing that foodborne illness in the United States, investigation that identified a novel isolates were closely related to those causing an estimated 63 000 illnesses, food vehicle, soy nut butter, as the in the initial cluster and an 2000 hospitalizations, and 20 source of a multistate foodborne epidemiological link to the suspected deaths annually.1 The highest illness outbreak, which mainly vehicle. We defined an outbreak- incidence of laboratory-confirmed affected young children. associated case as infection with 1 of STEC O157 infection occurs in 3 E coli O157:H7 PFGE Xbal-Blnl State public health laboratories children ,5 years old (3.72 infections pattern combinations constituting the 2 throughout the United States per 100 000 people in 2015). outbreak strains in a person with routinely perform molecular-based Symptoms include abdominal cramps illness onset between January 1, subtyping of clinical isolates using and diarrhea, which frequently 2017, and April 30, 2017. We used pulsed-field gel electrophoresis becomes bloody by the second or PulseNet throughout the investigation (PFGE).16,17 Clinical isolates are third day of illness.3 Symptoms to identify additional cases. obtained when clinicians order typically begin 3 to 4 days after laboratory testing as part of infection and last 6 to 8 days.3,4 Epidemiological Investigation a patient’s diagnostic evaluation. Approximately 5% to 10% of STEC Local and state health departments PFGE patterns are uploaded by infections are complicated by interviewed case patients or their participating laboratories to PulseNet, hemolytic uremic syndrome (HUS), proxies (eg, parents, guardians, or the national molecular subtyping which is characterized by caregivers) with state-specific enteric network for foodborne disease microangiopathic hemolytic anemia, disease questionnaires or a modified surveillance. The Centers for Disease thrombocytopenia, and acute renal version of the National Hypothesis – Control and Prevention (CDC) failure.3 6 HUS usually occurs 1 week Generating Questionnaire (NHGQ). PulseNet team detects potential after symptom onset, when diarrhea The NHGQ includes questions on multistate outbreaks of STEC and is improving.7 Among children .300 food and animal exposures in other enteric bacteria by identifying ,5 years old infected with STEC the week before illness, including clusters of uploaded isolates with O157, ∼15% develop HUS.6 fresh produce, meats, dairy products, indistinguishable patterns, which are Foodborne STEC O157 outbreaks and processed foods.18 After early more likely to be from a common have previously been associated with interviews narrowed the list of source. These clusters are referred to undercooked beef, raw produce (such potential exposures, investigators epidemiologists for investigation to as leafy vegetables and sprouts), interviewed case patients with determine if the illnesses are linked unpasteurized dairy and cider a focused questionnaire, which to a common vehicle. products, deli meats, raw dough, and included detailed questions on 8–11 dough mix. On February 17, 2017, PulseNet suspected foods. Investigators detected 7 E coli O157:H7 infections attempted to identify illness Peanut allergies have increased in Arizona, California, Maryland, and subclusters, in which 2 or more among US children over the past New Jersey with an indistinguishable unrelated case patients had exposure decades, leading some child care PFGE Xbal-Blnl restriction enzyme to the same location or venue before centers and schools to implement pattern combination that had not illness, such as a child care center or 12,13 peanut-free policies. In a 2014 been previously seen in the PulseNet restaurant, to narrow the scope of survey, 36% of school districts database. Local and state health suspected foods. banned foods because of allergies, departments, the CDC, and the US fi Product Traceback and Facility and 97% of these districts speci cally Food and Drug Administration (FDA) 13 Investigations banned peanuts. Consequently, initiated an investigation to peanut butter alternatives have determine the source of the outbreak Local, state, and FDA investigators gained popularity in the United States and prevent additional illnesses. conducted a traceback investigation because parents and caregivers seek of the suspected product and its safe alternatives for their ingredients through the distribution children.14,15 Peanut butter METHODS chain to determine if there was substitutes include spreads made a common source. Local and state fi from tree nuts (such as almonds, Case De nition and Case Finding investigators collected food menus pistachios, walnuts, and pecans) During the investigation, 2 STEC from child care centers and other and nut alternatives (such