Understanding Foodborne Illness: Causes, Symptoms & How to Stay Safe

WHAT IS FOODBORNE ILLNESS?

Foodborne illness, also known as food poisoning, is caused by consuming contaminated food or beverages. A variety of bacteria, viruses, and parasites can cause most cases of food poisonings, while some cases can also be caused by harmful toxins or chemicals [1].

According to CDC data, over 9,000 foodborne illness outbreaks were reported between 2011 and 2022 across all 50 states [2].

WHY DO WE CARE?

• Complications: Foodborne illness is easily overlooked, as the symptoms are mostly acute, and patients can get better without medications. However, in severe cases, foodborne illness can lead to life-threatening complications, i.e. dehydration, hemorrhage, hyperpyrexia, severe diarrhea, vomiting, dehydration, HUS, sepsis [3].

• Underdiagnosis & Underreporting: CDC largely relies on public health authorities across the country to voluntarily report cases of foodborne illness, but only a small fraction of foodborne cases were diagnosed and reported to public health authorities. According to the CDC, one of the reasons why some cases of foodborne illness may not be investigated or reported is because of resource limitations at the state or local level [2].

OVERVIEW OF FOOD PRODUCTION CHAIN

Foods can become contaminated at multiple points along the food chain before reaching consumers, including during production, processing, distribution, restaurant preparation, and home preparation [2].

ENVIRONMENTAL, SOCIAL & ECONOMIC FACTORS

• Age

• Socioeconomic Status (SES)

• Race

• Temperature

• Retail Food Services

CLINICAL CARE & BEHAVIORAL FACTORS

• Food Safety Attitudes & Behaviors

• Raw Food Consumption

• Chronic Diseases

Food Production Chain and Examples of Sources of Contamination [2]

ENVIRONMENTAL, SOCIAL & ECONOMIC RISK FACTORS OF FOODBORNE ILLNESS

Age High-risk age groups for foodborne illness symptoms [4]	Anyone at any age could have foodborne illness. However, certain age groups are more likely to have exacerbating symptoms. Therefore, it's important to prioritize these groups in preventing foodborne illness. Higher risk groups include people who are aged 65 or older or children under the age of 5 [4]. These age groups are more susceptible to foodborne illness because their immune systems are either weakened or underdeveloped, making it harder for their bodies to recognize and fight off germs effectively [4].
Socioeconomic Status (SES) Association of Domestic Salmonella Case Incidence in Children <5 Years Old With Census Tract Poverty by Race/Ethnicity and Foodborne Diseases Active Surveillance Network Site [7]	Those with a graduate education and those with higher education levels and thereby higher income levels were most likely to eat pink ground beef (a common cause of food poisoning) [5]. Lower household income and lower level of parental education were associated with greater exposure of children to raw products [6]. A FoodNet study conducted between 2010 and 2016 found that domestic cases of Salmonella were significantly associated with higher poverty levels in census tracts. This is particularly true for children under 5 years old, who were 50% more likely to report an infection if they lived in high-poverty areas [7].
Race Incidence rates (per 100,000 population) from foodborne illness in different racial groups (FoodNet Final Reports 2008-2011) [8] Note: updated data can be found on FoodNet.	Rates of illness among minority populations (African Americans, Hispanic, Asians) as compared to Caucasians vary by pathogens. Some differences are: Samonella: Minority populations suffer from a greater incidence of salmonellosis than Caucasians [8]. E. coli: Caucasians suffering from the highest incidence rates of E. coli O157:H7 infection and the lowest rates were from African Americans [8]. Shigella: Hispanics and African Americans, but not Asians, experience greater incidence of Shigella when compared to Caucasians [8].
Temperature Time/temperature control for safety (TCS) food [14]	Temperature and moisture play a critical role in the growth and survival of foodborne pathogens, as improper temperature increase the metabolic activity of microorganisms, allowing them to grow and reproduce more rapidly. For example, Salmonella, Escherichia coli (E. coli), and Campylobacter jejuni are the most common food-borne pathogens that thrive in warm and humid environments [9-12]. According to Minnesota Department of Agriculture: "Time/temperature control for safety (TCS) food" means a food that requires time and temperature control to limit pathogenic microorganism growth or toxin formation. Keep refrigerated TCS foods at 41°F or below, and TCS food that is held hot at 135°F or above. Anything in between is often referred to as the ‘Danger Zone’ as harmful bacteria can grow rapidly within this temperature range" [13].
Retail Food Service Out-of-Compliance Risk Factors in Fast Food and Full-Service Restaurants [16]	One recent study compared food samples taken from corner stores in poorer areas, with similar samples from larger supermarkets and chain convenience markets in more affluent census tracts within the Philadelphia metropolitan region, and found higher levels of bacteria contamination on products like fresh produce and milk in the corner stores. The result showed that “small, independently owned corner markets operating in urban areas with populations of low socioeconomic status (SES) may experience barriers to food safety including pest infestation, poor infrastructure and refrigeration, language, limited resources, and small or untrained staff" [15]. The FDA has conducted a 10-year study (2013-2024) and reported that fast-food and full-service restaurants as key sources of risk due to widespread noncompliance with food safety practices. The most common violations were improper holding temperatures (77% of fast food restaurants and 94% of full-service restaurants) and poor hygiene (61% of fast food restaurants and 77% of full-service restaurants) [16].

CLINICAL CARE & BEHAVIORAL RISK FACTORS OF FOODBORNE ILLNESS

Food Safety Attitudes & Behaviors Walmart's Food Safety High Five [19]	Food safety attitudes, behaviors, and hygiene practices are direct risk factors for foodborne illness. At the retail food facility level, food safety violations can occur in restaurants due to noncompliant practices. At the individual level, improper food handling, cooking, or storage at home can also contribute to foodborne illness. The most common food safety behaviors that increase the risk of foodborne illness include: Contaminated Equipment/ Cross-Contamination Poor Personal Hygiene Improper Holding Temperatures Improper Cooking Temperatures [17] Food safety behaviors are more alarming in low-income regions. In a study published in 2020, they showed that participants from low-income families had limited knowledge of food safety. Only 26.9% knew the kitchen sink should be sanitized daily. Most understood basic handwashing and food washing but had poor knowledge about pathogens and cross-contamination. 7.3% always used raw eggs in uncooked dishes. 4.7% left cooked meat out for over 4 hours [18].
Raw Food Consumption	Undercooked meat and eggs, unwashed fruits and vegetables, and unpasteurized milk are more often associated with foodborne illnesses.
Chronic Diseases Common types of chronic diseases in the U.S. [21]	A lot of chronic conditions may also make a person's risk of foodborne illness higher. This can be explained by a weakened immune system, which is often the result of conditions like diabetes [20].

WHAT WE SHOULD DO

Solutions	Food Safety Education in Community Settings	Policy & Infrastructure Support for Safe Food Environments
Activities	Deliver community-based food safety education programs, including workshops on hand hygiene, cross-contamination, safe food storage, and cooking practices. These can be conducted through schools, local clinics, and food banks.	Implement local policies that support safer retail and home food environments. Examples include encouraging grocery stores to improve food safety infrastructure (refrigeration, labeling), and supporting safer storage conditions in public food programs.
Target Population	Materials and delivery are tailored to local context, including literacy level, cultural food practices, and common household barriers (e.g., lack of thermometers or clean water).	Focused on low-resource areas with known access issues (e.g., food deserts, rural counties), especially those with high food insecurity and limited retail options.
Immediate Outcomes	Increased awareness and improved food safety behaviors in the home, such as correct handwashing, separating raw and cooked foods, and ensuring proper cooking temperatures.	Improved safety and quality of food in retail and pantry environments; fewer temperature abuse and cross-contamination risks.
Sustainability	Partner with local health departments and extension programs to train peer educators and community health workers to continue workshops long-term. These behavior changes reduce food contamination at the household level, aligning with Healthy People 2030's goal to reduce foodborne illness outbreaks.	Strengthening environmental and retail food safety contributes to a population-level reduction in foodborne illness.

References

1.      National Institute of Diabetes and Digestive and Kidney Diseases. Food poisoning. U.S. Department of Health and Human Services. https://www.niddk.nih.gov/health-information/digestive-diseases/food-poisoning

2.      U.S. Government Accountability Office. (2025). Food safety: Status of foodborne illness in the U.S. https://www.gao.gov/assets/gao-25-107606.pdf

3.      Centers for Disease Control and Prevention. (2024). Signs and symptoms of food poisoning. https://www.cdc.gov/food-safety/signs-symptoms/index.html

4.      Centers for Disease Control and Prevention. (2024). Foodborne illness risk factors. https://www.cdc.gov/food-safety/risk-factors/index.html

5.      Taylor, E. V., Holt, K. G., Mahon, B. E., Ayers, T., Norton, D., & Gould, L. H. (2012). Ground beef consumption patterns in the United States, FoodNet, 2006 through 2007. Journal of food protection, 75(2), 341–346. https://doi.org/10.4315/0362-028X.JFP-11-333

6.      Patrick, M. E., Mahon, B. E., Zansky, S. M., Hurd, S., & Scallan, E. (2010). Riding in shopping carts and exposure to raw meat and poultry products: prevalence of, and factors associated with, this risk factor for salmonella and campylobacter infection in children younger than 3 years. Journal of food protection, 73(6), 1097–1100. https://doi.org/10.4315/0362-028x-73.6.1097

7.      Hadler, J. L., Clogher, P., Libby, T., Wilson, E., Oosmanally, N., Ryan, P., Magnuson, L., Lathrop, S., Mcguire, S., Cieslak, P., Fankhauser, M., Ray, L., Geissler, A., & Hurd, S. (2020). Relationship Between Census Tract-Level Poverty and Domestically Acquired Salmonella Incidence: Analysis of Foodborne Diseases Active Surveillance Network Data, 2010-2016. The Journal of infectious diseases, 222(8), 1405–1412. https://doi.org/10.1093/infdis/jiz605

8.      Quinlan J. J. (2013). Foodborne illness incidence rates and food safety risks for populations of low socioeconomic status and minority race/ethnicity: a review of the literature. International journal of environmental research and public health, 10(8), 3634–3652. https://doi.org/10.3390/ijerph10083634

9.      U.S. Climate Resilience Toolkit. (n.d.). Food and water-related threats. https://toolkit.climate.gov/food-and-water-related-threats#:~:text=Across%20the%20United%20States

10. Awad, D.A., Masoud, H.A. & Hamad, A. Climate changes and food-borne pathogens: the impact on human health and mitigation strategy. Climatic Change 177, 92 (2024). https://doi.org/10.1007/s10584-024-03748-9

11. Dietrich J, Hammerl J-A, Johne A et al (2023) Impact of climate change on foodborne infections and intoxications. J Health Monit 8:78–92. https://doi.org/10.25646/11403

12. Qiu Y, Zhou Y, Chang Y et al (2022) The effects of Ventilation, Humidity, and temperature on bacterial growth and bacterial genera distribution. Int J Environ Res Public Health 19:15345. https://doi.org/10.3390/ijerph192215345

13. Minnesota Department of Agriculture. Foodborne illness risk factors. https://www.mda.state.mn.us/food-feed/foodborne-illness-risk-factors

14. FoodReady. Time and temperature controls: What are TCS foods? https://foodready.ai/blog/time-and-temperature-controls-what-are-tcs-foods/

15. Signs, R. J., Darcey, V. L., Carney, T. A., Evans, A. A., & Quinlan, J. J. (2011). Retail food safety risks for populations of different races, ethnicities, and income levels. Journal of food protection, 74(10), 1717–1723. https://doi.org/10.4315/0362-028X.JFP-11-059

16. U.S. Food and Drug Administration. (2018). FDA report on the occurrence of foodborne illness risk factors in fast-food and full-service restaurants, 2017–2018. Technical Report.

17. Holst MM, Wittry BC, Crisp C, Torres J, Irving D, Nicholas D. Contributing Factors of Foodborne Illness Outbreaks — National Outbreak Reporting System, United States, 2014–2022. MMWR Surveill Summ 2025;74(No. SS-1):1–12. DOI: http://dx.doi.org/10.15585/mmwr.ss7401a1.

18. Liu, P. (2020). Food safety knowledge and practice in low-income families in the U.S.: An exploratory study. Food Protection Trends, 40(2), 80–94.

19. Stop Foodborne Illness. (n.d.). Frank Yiannas: Courage and commitment. https://stopfoodborneillness.org/candc-frank_yiannas/

20. FoodSafety.gov. Older adults. https://www.foodsafety.gov/people-at-risk/older-adults

21. Prime Health of New Jersey. What is a chronic disease? https://primehealthofnj.com/what-is-a-chronic-disease/

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