Ground beef is a common source of US Salmonella illnesses and outbreaks. However, the demographic and socioeconomic factors that are related to risk in ground beef-associated outbreaks of Salmonella infections are poorly understood. We describe the individual-level demographic characteristics and county-level indicators of social vulnerability for people infected with Salmonella linked to outbreaks associated with ground beef in the United States during 2012-2018. Non-Hispanic (NH) White and NH American Indian/Alaska Native persons, and people living in nonmetropolitan areas, were overrepresented among people in salmonellosis outbreaks linked to ground beef. Case patients disproportionately resided in counties with high social vulnerability, suggesting that one or more community social risk factors may contribute to or be associated with some food safety risks. Collecting and analyzing socioeconomic and demographic characteristics of people in outbreaks can help identify disparities in foodborne disease, which can be further characterized and inform equity-focused interventions.
The Centers for Disease Control and Prevention (CDC), working closely with public health and regulatory partners, investigate outbreaks of foodborne illness. Outbreak investigations continue to identify melons as an important source of outbreak-associated illness. We characterized the epidemiology of outbreaks linked to melons from 2012 to 2021, summarized public health responses to these outbreaks, and identified potential opportunities for prevention efforts and interventions. We queried CDC's Foodborne Disease Outbreak Surveillance System (FDOSS) for all Salmonella, Escherichia coli (E. coli), and Listeria monocytogenes outbreaks linked to melons and collected data from the U.S. Food and Drug Administration's (FDA) Coordinated Outbreak Response & Evaluation (CORE) Network internal databases for information regarding outbreak investigations that involved FDA's evaluation and response activities. Descriptive statistics were calculated for outbreaks overall, by melon type, and by etiology, including the number of outbreaks, illnesses, hospitalizations, deaths, patient demographics including sex and age, outbreak duration, investigation duration, seasonality, serotypes, and food preparation and consumption settings. During 2012-2021, 18 outbreaks were linked to melons. The median number of outbreaks per year was 2 (range: 0-3); there were no melon-associated outbreaks reported in 2015. These 18 outbreaks resulted in 821 illnesses, 251 hospitalizations, and 10 deaths. More than half of the melon-associated Salmonella outbreaks in this reporting timeframe were linked to cantaloupe. Outbreak illnesses clustered in the U.S. Midwest and in outbreaks where the growing area was known, most were produced domestically (4/7, 57%), frequently grown in Indiana. Traceback and epidemiologic investigations demonstrated that contamination can occur at all points along the farm-to-fork continuum, requiring the need for pathogen control at every step.
Food irradiation can reduce foodborne illnesses but is rarely used in the United States. We determined whether outbreaks related to Campylobacter, Salmonella, Escherichia coli, and Listeria monocytogenes were linked to irradiation-eligible foods. Of 482 outbreaks, 155 (32.2%) were linked to an irradiation-eligible food, none of which were known to be irradiated.
Salmonella is estimated to be the leading bacterial cause of U.S. domestically acquired foodborne illness. Large outbreaks of Salmonella attributed to ground beef have been reported in recent years. The demographic and sociodemographic characteristics of infected individuals linked to these outbreaks are poorly understood. We employed a retrospective case-control design; case-patients were people with laboratory-confirmed Salmonella infections linked to ground beef-associated outbreaks between 2012 and 2019, and controls were respondents to the 2018-2019 FoodNet Population Survey who reported eating ground beef and denied recent gastrointestinal illness. We used county-level CDC/ATSDR Social Vulnerability Index (SVI) to compare case-patient and controls. Case-patient status was regressed on county-level social vulnerability and individual-level demographic characteristics. We identified 376 case-patients and 1,321 controls in the FoodNet sites. Being a case-patient was associated with increased overall county-level social vulnerability (OR: 1.21 [95% CI: 1.07-1.36]) and socioeconomic vulnerability (OR: 1.24 [1.05-1.47]) when adjusted for individual-level demographics. Case-patient status was not strongly associated with the other SVI themes of household composition and disability, minority status and language, and housing type and transportation. Data on individual-level factors such as income, poverty, unemployment, and education could facilitate further analyses to understand this relationship.
Listeria monocytogenes causes listeriosis, a serious infection with a high mortality rate for persons at higher risk for listeriosis. The first Listeria outbreak linked to frozen vegetables occurred in 2016 and resulted in three deaths. Many frozen vegetables are intended to be consumed after cooking. However, data on consumer behavior are sparse. We characterized consumers' perceptions of contamination of prepackaged frozen vegetables, and preparation methods of prepackaged frozen vegetables to help inform prevention strategies. During September 1-24, 2022, Porter Novelli Public Services conducted the FallStyles survey using the Ipsos KnowledgePanel. Data were weighted to be representative of the U.S. population. Point estimates and 95% CIs were calculated, and differences between respondents were determined using Wald chi square tests. Among 3,008 respondents reporting a preparation and consumption method for frozen vegetables, 8.7% (95% CI = 7.4-10.0%) reported ever consuming the product raw. Respondents who reported having children < 18 years old were more likely to report ever consuming frozen vegetables raw compared with respondents who did not (12.5% vs. 7.4%, p < 0.01). The most reported raw preparation method was adding them directly to a blender for smoothie or juice (5.6%; 95% CI = 4.6-6.7%). Among respondents who reported eating frozen vegetables, 59.6% (95% CI = 57.6-61.6%) reported following package instructions. A third (34.1% [95% CI = 32.2-35.9%]) of respondents agreed that frozen vegetables can be contaminated with germs (like Salmonella, E. coli, and Listeria), with a greater proportion of people with cancer disagreeing compared to those without cancer (32.5% vs 23.4%, p = 0.041). These findings show that some consumers may not be cooking frozen vegetables before eating them. Second, consumers might not be reading instructions on packaging. Both findings highlight the critical importance of preventive controls in the production of frozen vegetables prior to reaching the consumer.
Foodborne illness continues to be a substantial public health concern in the United States with contaminated ground beef, chicken, and leafy greens identified as important sources of illnesses and outbreaks. These foods also have been identified by consumers as foods that are likely to carry germs that can make people sick. Food irradiation is a promising tool to enhance food safety. Despite this, there has been limited application of food irradiation in the U.S. During October 7-9, 2022, we licensed data from a Porter Novelli Public Services survey (N = 1,008) to examine consumer risk perception of contamination of ground beef, chicken, and leafy greens with pathogens, and the potential influence risk perception has on purchasing irradiated versions of these foods. Among respondents familiar with food irradiation, a higher proportion of those who believed ground beef and leafy greens were likely contaminated also indicated they were likely to consider purchasing irradiated ground beef (55.6% vs 35.4%; p = 0.0061) and leafy greens (60.8% vs 36.1%; p ≤ 0.0001) compared with those who did not; chicken was not significant (58.6% vs 45.4%; p = 0.0727). This survey demonstrated the importance of risk perception as an influencer on a consumer's decision to purchase irradiated foods.
Over 20% of E. coli O157 illnesses and over 5% of Salmonella illnesses are estimated to be attributable to beef consumption in the United States. Irradiating ground beef is one possible method to reduce disease burden. We simulated the effect of ground beef irradiation on illnesses, hospitalizations, deaths, and direct healthcare costs from ground beef-associated E. coli O157 and Salmonella illnesses in the United States. To estimate the fraction of illnesses, hospitalizations, deaths, and direct healthcare costs preventable by ground beef irradiation, we multiplied the disease burden attributable to ground beef; the estimated percentage of ground beef sold that is not currently irradiated; the percentage of unirradiated ground beef that would be irradiated; and the percentage reduction in risk of illness after irradiation. We multiplied this fraction by estimates of burden and direct healthcare costs to calculate the numbers or amounts averted. Model inputs were obtained from the literature and expert opinion. We used Monte Carlo simulation to incorporate uncertainty in inputs into model estimates. Simulation outcomes were summarized with means and 95% uncertainty intervals (UI). Irradiating 50% of the currently unirradiated ground beef supply would avert 3,285 (95% UI: 624–9,977) E. coli O157 illnesses, 135 (95% UI: 24–397) hospitalizations, 197 (95% UI: 34–631) hemolytic uremic syndrome cases, 2 (95% UI: 0–16) deaths, and $2,972,656 (95% UI: $254,708–$14,496,916) in direct healthcare costs annually. For Salmonella, irradiation would avert 20,308 (95% UI: 9,858–38,903) illnesses, 400 (95% UI: 158–834) hospitalizations, 6 (95% UI: 0–18) deaths, and $7,318,632 (95% UI: $1,436,141–$26,439,493) in direct healthcare costs. Increasing ground beef irradiation could reduce E. coli O157 and Salmonella burden in the United States. Additional studies should assess whether targeted irradiation of higher-risk ground beef products could prevent similar numbers of illnesses with less total product irradiated.
Over 20% of E. coli O157 illnesses and over 5% of Salmonella illnesses are estimated to be attributable to beef consumption in the United States. Irradiating ground beef is one possible method to reduce disease burden. We simulated the effect of ground beef irradiation on illnesses, hospitalizations, deaths, and direct healthcare costs from ground beef-associated E. coli O157 and Salmonella illnesses in the United States. To estimate the fraction of illnesses, hospitalizations, deaths, and direct healthcare costs preventable by ground beef irradiation, we multiplied the disease burden attributable to ground beef; the estimated percentage of ground beef sold that is not currently irradiated; the percentage of unirradiated ground beef that would be irradiated; and the percentage reduction in risk of illness after irradiation. We multiplied this fraction by estimates of burden and direct healthcare costs to calculate the numbers or amounts averted. Model inputs were obtained from the literature and expert opinion. We used Monte Carlo simulation to incorporate uncertainty in inputs into model estimates. Simulation outcomes were summarized with means and 95% uncertainty intervals (UI). Irradiating 50% of the currently unirradiated ground beef supply would avert 3,285 (95% UI: 624-9,977) E. coli O157 illnesses, 135 (95% UI: 24-397) hospitalizations, 197 (95% UI: 34-631) hemolytic uremic syndrome cases, 2 (95% UI: 0-16) deaths, and $2,972,656 (95% UI: $254,708-$14,496,916) in direct healthcare costs annually. For Salmonella, irradiation would avert 20,308 (95% UI: 9,858-38,903) illnesses, 400 (95% UI: 158-834) hospitalizations, 6 (95% UI: 0-18) deaths, and $7,318,632 (95% UI: $1,436,141-$26,439,493) in direct healthcare costs. Increasing ground beef irradiation could reduce E. coli O157 and Salmonella burden in the United States. Additional studies should assess whether targeted irradiation of higher-risk ground beef products could prevent similar numbers of illnesses with less total product irradiated.
Over 40% of all U.S. Salmonella illnesses are attributed to consumption of contaminated meat and poultry products each year. Determining which serotypes cause the most outbreak illnesses associated with specific meat and poultry types can inform prevention measures. We developed an approach to categorize serotypes using outbreak illness burden (high, moderate, low) and trajectory (increased, stable, decreased). We used data from 192 foodborne Salmonella outbreaks resulting in 7,077 illnesses, 1,330 hospitalizations, and 9 deaths associated with chicken, turkey, beef, or pork during 2012-2021. We linked each meat and poultry type to 1-3 serotypes that we categorized as high outbreak illness burden and increased trajectory during 2021. Calculation and public display of outbreak illness burden and trajectory annually could facilitate the prioritization of serotypes for prevention by federal and state health and regulatory agencies and by the meat and poultry industry.
Foodborne illness affects approximately 48 million Americans annually. Food irradiation is a safe and effective way to kill bacteria and extend a product’s shelf life. However, challenges to wider implementation of this technology include consumer hesitancy stemming from misconceptions about safety and lack of knowledge of irradiation’s benefits. Research has shown that consumers are more willing to accept irradiation if informed about its safety. Because of increases in multistate foodborne outbreaks and consumers’ growing concern about and expectation of food safety, it is an opportune time to reconsider irradiation as a food safety tool. Consumer attitudes toward food safety differ by demographic characteristics; however, research on the association of demographic factors with attitudes on food irradiation are limited. Data collected from a survey (n = 1,009) conducted in August 2022 were analyzed to describe the relationship between age and food irradiation knowledge as influential factors to purchase irradiated foods. More than half (56%) of respondents reported that learning more about irradiation would likely influence purchasing decisions, and older adults were more knowledgeable about food irradiation. These findings suggest that age could be an important factor to consider when tailoring messaging as a prevention strategy around the benefits of food irradiation.
In 2016, the U.S. Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC), and state partners investigated nine Listeria monocytogenes infections linked to frozen vegetables. The investigation began with two environmental L. monocytogenes isolates recovered from Manufacturer A, primarily a processor of frozen onions, that were a match by whole genome sequencing (WGS) to eight clinical isolates and historical onion isolates with limited collection details. Epidemiologic information, product distribution, and laboratory evidence linked suspect food items, including products sourced from Manufacturer B, also a manufacturer of frozen vegetable/fruit products, with an additional illness. The environmental isolates were obtained during investigations at Manufacturers A and B. State and federal partners interviewed ill people, analyzed shopper card data, and collected household and retail samples. Nine ill persons between 2013 and 2016 were reported in four states. Of four ill people with information available, frozen vegetable consumption was reported by three, with shopper cards confirming purchases of Manufacturer B brands. Two identified outbreak strains of L. monocytogenes (Outbreak Strain 1 and Outbreak Strain 2) were a match to environmental isolates from Manufacturer A and/or isolates from frozen vegetables recovered from open and unopened product samples sourced from Manufacturer B; the investigation resulted in extensive voluntary recalls. The close genetic relationship between isolates helped investigators determine the source of the outbreak and take steps to protect public health. This is the first known multistate outbreak of listeriosis in the United States linked to frozen vegetables and highlights the significance of sampling and WGS analyses when there is limited epidemiologic information. Additionally, this investigation emphasizes the need for further research regarding food safety risks associated with frozen foods.
Food irradiation has been studied comprehensively and has been determined to be a safe and effective process for improving food safety. Despite this potential public health impact and current use in developed countries, the technology is not commonly used in the United States, with consumer acceptance often cited as a barrier. Given changes in consumer food-purchasing trends, advancements in irradiation technology, and an increase in multistate foodborne outbreaks, it is an opportune time to revisit consumer acceptance and factors that influence the purchase of irradiated food. We conducted seven focus groups to assess knowledge, attitudes, and practices regarding irradiation as a food safety intervention. Meetings were virtual, lasted 90 min, and were held March 15–18, 2021. Participants were stratified into three groups using quota sampling: adults aged 18–64 years, parents of children aged 0–4 years, and adults aged 65 years and older. Consistent with past research, consumers were unaware of what food irradiation is. Facilitators for purchasing irradiated foods included protection from foodborne illness, reduced risk from certain foods, and support from public health agencies. Barriers included lack of knowledge, safety concerns, price, packaging, and a distrust of food technology. The results from these focus groups can inform public messaging and foodborne illness prevention strategies.
The Centers for Disease Control and Prevention (CDC) has identified nontyphoidal Salmonella as one of the top five pathogens contributing to foodborne illnesses in the United States. Beef continues to be a common source of Salmonella outbreaks, despite the implementation of interventions at slaughter and processing facilities to reduce contamination of beef. We described Salmonella outbreaks linked to beef in the United States during 2012-2019, examined trends, and identified potential targets for intervention and prevention strategies. We queried CDC's Foodborne Disease Outbreak Surveillance System (FDOSS) for all foodborne nontyphoidal Salmonella outbreaks linked to beef as the single contaminated ingredient or implicated food, with the date of first illness onset from 2012 to 2019. Information on antimicrobial resistance (AR) for outbreak-related iso- lates was obtained from CDC's National Antimicrobial Resistance Monitoring System (NARMS). We calculated the number of outbreaks, outbreak-related illnesses, hospitalizations, and deaths overall, by beef processing category and Salmonella serotype. During 2012-2019, 27 Salmonella outbreaks were linked to beef consump- tion, resulting in 1103 illnesses, 254 hospitalizations, and two deaths. The most common category of beef implicated was nonintact raw, ground beef (12 outbreaks, 44%), followed by intact raw (six outbreaks, 22%). Ground beef was responsible for the most illnesses (800, 73%), both of the reported deaths, and was the source of the largest outbreak. AR data were available for 717 isolates from 25 (93%) outbreaks. Nine (36%) of these outbreaks had isolates resistant to one or more of the antibiotics tested by NARMS, of which eight (89%) contained multidrug-resistant isolates. Several outbreaks reported highlight challenges faced dur- ing investigations, areas where further research may be warranted, and opportunities to prevent future out- breaks along the farm-to-fork continuum.
Frozen stuffed breaded raw chicken products have repeatedly been implicated in Salmonella outbreaks (1). These products are partially cooked to set the breading, often making them appear cooked (2). Despite their appearance, these products need to be cooked to an internal temperature of 165°F (74°C) to ensure that they are safe to eat. Producers began implementing labeling changes in 2006 to more clearly identify these products as raw; many warn against using microwave ovens (microwaves) to prepare them and provide validated cooking instructions solely for conventional ovens (ovens) (3,4). However, outbreaks continued to occur after implementation of these labeling changes (4). To describe the demographic characteristics of persons who prepare frozen stuffed chicken products and which appliances they use to prepare them, data from a May-July 2022 representative panel survey were analyzed. Although most (82.7%) respondents used an oven as one of their cooking methods, more than one half (54.0%) of respondents also used another appliance, including 29.0% who used a microwave. Oven use was lower among respondents with household income <$25,000 (68.9%), and who lived in mobile homes or other portable types of homes (66.5%). Among respondents who reported using microwaves to cook these products, 8% reported using a microwave with ≤750 W of power, which might be insufficient to thoroughly cook such products (1,5,6). Economic and other factors might influence some groups' access to recommended cooking appliances. Companies could consider implementing additional interventions that rely less on labeling and consumer preparation practices and focus on controlling or reducing levels of Salmonella in these products, such as selling them fully cooked, or monitoring and testing Salmonella levels, to ensure safety. These findings highlight challenges consumers might face in preparing frozen stuffed chicken products safely and can guide strategies for regulatory authorities and industry to prevent outbreaks and illnesses associated with them.
Hale, Deborah MSN, RN, ACNS-BC; Marshall, Katherine DNP, NP, PMHCNS-BC, CNE Author Information
The Centers for Disease Control and Prevention (CDC) coordinates investigations of multistate foodborne outbreaks. To better inform future communication efforts with the public during these outbreaks, we conducted a qualitative content analysis of comments on multistate foodborne outbreak Facebook posts distributed on the CDC's Facebook page September to December 2018. The CDC created 27 Facebook posts for nine multistate foodborne outbreaks (one to eight posts per outbreak), and 2,612 comments were analyzed. The CDC used two Web tools to deliver outbreak information: food safety alerts (FSAs) and investigation notices (INs). Qualitative analyses were conducted separately for Facebook posts resulting from FSAs and INs. Using an inductive coding approach, we identified nine categories of comments: information sharing (e.g., tagging others), actions (e.g., discarding contaminated food), convictions and beliefs (e.g., food-related preconceived notions), questions (e.g., clarifying outbreak location), emotional responses (e.g., worry), blame (e.g., responsibility for outbreak), food specific (e.g., repackaging ground beef and losing identifying information), promoting another cause (e.g., vaccine hesitancy), and unrelated. No differences were found between FSAs and INs. Facebook users helped further disseminate important outbreak information but identified barriers that prevented them from taking recommended actions. Real-time evaluation of social media during outbreaks provides opportunities to refine messaging and improve communication.
Abstract Gatherings where people are eating and drinking can increase the risk of getting and spreading SARS-CoV-2 among people who are not fully vaccinated; prevention strategies like wearing masks and physical distancing continue to be important for some groups. We conducted an online survey to characterise fall/winter 2020–2021 holiday gatherings, decisions to attend and prevention strategies employed during and before gatherings. We determined associations between practicing prevention strategies, demographics and COVID-19 experience. Among 502 respondents, one-third attended in person holiday gatherings; 73% wore masks and 84% practiced physical distancing, but less did so always (29% and 23%, respectively). Younger adults were 44% more likely to attend gatherings than adults ≥35 years. Younger adults (adjusted prevalence ratio (aPR) 1.53, 95% CI 1.19–1.97), persons who did not experience COVID-19 themselves or have relatives/close friends experience severe COVID-19 (aPR 1.56, 95% CI 1.18–2.07), and non-Hispanic White persons (aPR 1.57, 95% CI 1.13–2.18) were more likely to not always wear masks in public during the 2 weeks before gatherings. Public health messaging emphasizing consistent application of COVID-19 prevention strategies is important to slow the spread of COVID-19.
Objectives: Visiting restaurants and bars, particularly when doing so indoors, can increase transmission risk of SARS-CoV-2, the virus that causes COVID-19, among people who are not fully vaccinated. We aimed to understand US adults' self-reported protective behaviors when getting food from restaurants during the COVID-19 pandemic when vaccines were not widely available. Methods: We used online nationwide survey data from January 2021 to assess self-reported restaurant-related behaviors of respondents (n = 502). We also used multiple logistic regression models to examine associations between respondents' characteristics and these restaurant-related behaviors. Results: Half (49.7%) of respondents reported eating indoors at a restaurant at least once in the month before the survey. Respondents most likely to report eating inside restaurants were in the youngest age category (18-34 y), had personal COVID-19 experience, or indicated they felt safe eating inside a restaurant. Among respondents who had gotten food from a restaurant, more than 65% considered each of the following factors as important in their restaurant dining decision: whether the restaurant staff were wearing face masks, the restaurant requires face masks, other customers are wearing face masks, seating was spaced at least 6 feet apart, someone in their household was at risk for severe COVID-19 illness, and the restaurant was crowded. The most common protective behavior when eating at a restaurant was wearing a face mask; 44.9% of respondents who had eaten at a restaurant wore a face mask except when actively eating or drinking. Conclusion: The need for practicing prevention strategies, especially for those not up to date with COVID-19 vaccines, will be ongoing. Our findings can inform COVID-19 prevention messaging for public health officials, restaurant operators, and the public.
Many efforts across the farm-to-fork continuum aim to reduce foodborne disease and outbreaks. Real-time risk communication is an important component of the Centers for Disease Control and Prevention (CDC) efforts, especially during outbreaks. To inform risk communication with the public during multistate foodborne outbreaks, we conducted a series of focus groups of adults in the Washington, D.C., metropolitan area to understand attitudes, perceptions, behaviors, and how people receive information around foodborne disease outbreaks. Results from these focus groups provided insight on factors that might influence consumer perception and behavior during an outbreak. Perceived outbreak proximity and personal consumption of an outbreak vehicle were identified as also reported hearing about multiple outbreaks per year some drivers of perceived risk to an outbreak. Participants through a variety of sources and following recommended actions during an outbreak, implying some existing penetration of current risk messages for multistate foodborne outbreaks. Findings from these focus groups are a first step in increasing understanding of how CDC messages affect the consumers' ability to access and act upon reliable information to protect their health during outbreaks and serve as a baseline for further evaluation efforts of CDC risk communication strategy for multistate foodborne outbreaks.