Collecting and analyzing individual-level demographic characteristics and county-level indicators of social vulnerability among people with foodborne illnesses can identify factors associated with health disparities and ultimately enable more focused public health interventions. NH White people, NH AI/AN people, and people living in nonmetro counties were overrepresented among people in salmonellosis outbreaks linked to ground beef. Patients lived in counties that had higher vulnerability rankings for minority status and language and housing type and transportation than the mean of all US counties, suggesting that some aspects of community social vulnerability may contribute to some ground beef food safety risks. This report demonstrates how the social vulnerability framework might be useful to better understand who is affected by foodborne illness outbreaks in the United States.

NH White persons were overrepresented among people linked to ground beef-associated outbreaks. This finding could be partly due to differences in consumption of ground beef, and differences in opportunities for exposure to contaminated ground beef. Data from a survey of healthy people conducted in 15 US sites during 2018–2019 showed that NH White persons were the most likely to report eating ground beef in the previous week (71.5%), followed by Hispanic persons (63.7%), NH Black persons (58.4%), and people of another race (53.4%); data for AI/AN persons were not provided (Centers for Disease Control and Prevention (2022)). Differences in preferences for or cultural traditions around eating raw or undercooked ground beef could also contribute to our findings. From a meta-analysis of 20 studies, White persons (22%) were most likely to report consuming raw or undercooked ground beef compared with people who are Hispanic (14%), Asian (14%), or Black (7%); ground beef consumption information was not available for AI/AN people (Patil et al., 2005).

People with salmonellosis linked to ground beef lived in counties that had higher vulnerability rankings for the minority status and language (speaking English “less than well”) theme. This might be due to limited availability of food safety information for handling and storage of ground beef and training for those who store and handle ground beef in restaurants and grocery stores in languages other than English. Additionally, differences in preferences or cultural practices around handling and preparation of ground beef could help explain our findings if affected counties have a higher proportion of people who consume dishes traditionally made with raw beef. At least two outbreaks in this analysis were associated with culturally important raw ground beef dishes (i.e., kibbeh, kitfo). However, a separate analysis compared SVI themes for counties with people who had salmonellosis linked to ground beef with those who recently ate ground beef but did not report getting sick (Salah et al., 2024). The vulnerability rankings for the minority status and language SVI theme in that analysis were similarly high in both groups. This suggests that the observed findings may be partially attributed to increased consumption of ground beef in counties with high vulnerability related to minority status.

We found that a higher proportion of patients resided in nonmetro areas compared with the total US population. This might be partly explained by increased consumption of ground beef products in nonmetro areas. Previous studies have demonstrated that people living in rural communities consume ground beef more frequently than people living in urban communities (Taylor et al., 2012; Davis & Lin, 2005). Further, people living in rural areas may need to travel longer distances to grocery stores, which could expose ground beef to warmer temperatures, and for longer than the recommended limit (CDC, 2024d).

People linked to ground beef-associated Salmonella outbreaks lived in counties that were more vulnerable with respect to SVI Theme 4: Housing Type and Transportation, which includes measures for households with no vehicle available, living in mobile homes, living in a group home, or crowding (i.e., more people than rooms in a household). In the analysis where people with salmonellosis linked to ground beef were compared with people who recently ate ground beef, this SVI theme was no longer significant (Salah et al., 2024), therefore, it is possible that our findings from this analysis could be related to differences in consumption of ground beef. However, not having a vehicle and having to rely on public transportation to get to the grocery store might increase transit time and could expose ground beef to warmer temperatures for longer than the recommended limit (CDC, 2024d), allowing for growth of any pathogens that might already be present. Differences in availability, quality, and effectiveness of appliances and tools for storing and cooking ground beef related to housing type could also play a role in these findings. Refrigerators that are overcrowded or do not maintain an appropriate temperature could contribute to the growth of pathogens that are already present in ground beef. A lack of access to cooktops or ovens could contribute to challenges around cooking ground beef to 160F. Results of a survey of consumers regarding appliance use for preparing frozen stuffed chicken products showed that people who lived in mobile homes or with lower income reported lower use of ovens compared with microwaves, suggesting that economic and other factors might influence access to cooking appliances (Marshall et al., 2022). Finally, there could be differences in the availability of food safety information and training for those preparing food in group homes, which include college residence halls, residential treatment centers, nursing facilities, military barracks, correctional facilities, worker homes, and other types of group homes. A previous analysis found that people in correctional facilities face a disproportionate risk of foodborne illness outbreaks (Marlow et al., 2017). One study found that staff in group homes for people with developmental disabilities in Massachusetts lacked knowledge of safe food preparation in some key areas, including storage and handling, and identified a need for food safety training (Walter et al., 1997). While previous studies that have analyzed the associations between household-level characteristics and foodborne illness typically focus on income and education (Quinlan, 2023; Chang et al., 2009; Newman et al., 2015), our analysis suggests that housing type and transportation could also be important to consider when collecting and examining foodborne disease data and identifying interventions.

While we did not examine it in this analysis, it is possible there are differences in microbial quality of ground beef (e.g., prevalence of Salmonella) that retailers and consumers buy, which could influence the risk of illness. To our knowledge, no studies have examined whether there are systematic differences in the microbial quality of ground beef by retail location type (e.g., supermarket vs. small corner store), geography (i.e., region, or urban vs. rural areas), or characteristics of the communities they serve (e.g., race/ethnicity, socioeconomic status). A study conducted in the Philadelphia area did not find a difference in pathogen levels for meat and poultry across different retail types but did identify differences in microbial quality in produce at the retail level by community-level socioeconomic status (Koro et al., 2010). More research is needed to determine whether these and other differences are observed across the United States.

Given the multitude of factors, including social and structural factors, along the farm-to-fork continuum that may influence the risk for Salmonella infection associated with ground beef, exploring interventions that are applied to minimize contamination of ground beef in the first place and do not require modification of consumer behaviors are essential. These can include preharvest interventions such as vaccination of cattle and biosecurity, and interventions at slaughter and processing, including lymph node removal and irradiation (Edrington et al., 2020; Stuttgen, 2017; USDA, 2017; Castell-Perez and Moreira, 2020). To improve the effectiveness and acceptability of consumer-focused food safety interventions, cultural responsiveness and consideration of traditions are essential. The effectiveness of public food safety education efforts may be increased by incorporating formative research with disproportionately affected populations to understand knowledge, attitudes, perceived risks, and preferences and tailor educational strategies that include behavioral components (Young et al., 2017; Sivaramalingam et al., 2015; Siebert et al., 2014). For example, focus groups among American Indian participants identified the importance of framing education efforts around positive health rather than sickness, because associating sickness with food is culturally inappropriate (Siebert et al., 2014). Tailored health messaging and interventions have been shown to be more effective at driving long-term behavior change when compared to general, one size fits all health messaging and intervention strategies (Noar et al., 2007). The format, mechanisms, messengers, and languages for disseminating education and health messaging should also be tailored. Further, strategies that offer safer alternatives to prepare and consume culturally important or traditional foods (e.g., using irradiated ground beef for raw dishes) could be developed together with disproportionately impacted populations.

This report is subject to at least five limitations. First, analysis of individual-level demographic characteristics was performed on a small, nonrandom sample of all laboratory-confirmed salmonellosis cases that were reported as part of a ground beef-associated outbreak in CDC FDOSS. Further, state reporting to FDOSS is voluntary and it is possible that not all ground beef-associated Salmonella outbreaks were captured. Our findings do not represent all people who had ground beef-associated Salmonella infections. Second, CDC/ATSDR SVI is an area-based measure; individual patient sociodemographic characteristics may differ from the proxy measures applied to them in this analysis. Third, one outbreak (Outbreak 10) represented over half (59%) of all cases in this analysis. To assess whether observed differences in SVI themes were overly influenced by this single outbreak, we performed a sensitivity analysis excluding Outbreak 10 (Appendix). Demographic and geographic comparison interpretations were similar after excluding Outbreak 10. When assessing the weighted mean overall SVI rank of patient counties compared with the mean among all US counties, the difference for overall SVI rank was no longer significant, but the difference for SVI Theme 3 Minority Status and Language and Theme 4 Housing Type and Transportation remained significant. Fourth, whether an individual will become ill and how severe their illness might be after eating Salmonella-contaminated ground beef can depend on the dose, characteristics of the Salmonella strain, and host factors, including underlying illness. Further, diagnosis of a Salmonella infection and inclusion in an outbreak requires access to and utilization of healthcare. People who live in rural areas might have less access to healthcare (MacKinney et al., 2014; Leider et al., 2020). Groups that have greater healthcare access may be overrepresented among outbreak-related cases, and people with more severe illness may be more likely to seek care. While we did not assess any of these factors in this analysis, they are important considerations in understanding who becomes sick and is ultimately included in ground beef-associated outbreaks. Lastly, we were unable to evaluate the types of retail locations (e.g., grocery stores, restaurants) that received contaminated ground beef and the demographic characteristics and social vulnerability of communities served by them, as retail locations that received contaminated ground beef are determined only for outbreaks in which a recall occurs.

This report demonstrates how county-level SVI rankings can be useful to better understand the distribution of foodborne illness in the United States. County-level rankings for two SVI themes differed between patients and the general population, which suggests that stratifying by SVI theme is important to understand potential factors that could influence the risk for foodborne disease illness. Collecting and analyzing additional individual-level data and more complete and detailed demographic data, including further disaggregated race and ethnicity (e.g., tribal affiliation), could advance understanding of which social and demographic factors are most influential in foodborne illness. Applying SVI rankings to foodborne disease data also reinforces the importance of considering social determinants of health and drivers of health inequity, like language, household type, and transportation, in understanding potential risk factors for foodborne illness (CDC, 2024e). Interventions along the entire farm-to-fork continuum that reduce contamination of ground beef before it reaches consumers and consumer-focused interventions that are responsive to community and culture are needed to prevent foodborne illness.