Foodborne Illness: Diagnosis and Management

Alexis Reedy-Cooper, MD, MPH
Juan Perez, DO
Theresa Yurkonis, DO, MHSA

American Family Physician. 2026;114(3):283-294.

Author Disclosure: No relevant financial relationships.

This clinical content conforms to AAFP criteria for CME.

Foodborne illness affects an estimated 48 million people in the United States each year, resulting in 128,000 hospitalizations and 3,000 deaths. Causes of foodborne illnesses include viruses such as norovirus; bacteria such as Escherichia coli, Salmonella, Campylobacter, and Listeria; and parasites such as Giardia. Factors that contribute to foodborne illness include contamination of food by an animal or environmental source before final preparation, improper food handling by an ill worker, inadequate cooking, improper temperature control, and consumption of uncooked or unpasteurized foods. Common symptoms include vomiting, diarrhea, fever, and abdominal pain. Diagnosis and management of foodborne illness should be guided by epidemiologic context, host risk factors, and clinical severity. Empiric treatment includes symptom management, rehydration, and antibiotic therapy. Prevention of foodborne illnesses involves education on food recalls and proper storage, handling, and cooking of food. Foodborne illnesses should be reported to local and state health agencies.

Foodborne illness affects an estimated 48 million people in the United States each year, resulting in 128,000 hospitalizations and 3,000 deaths.1 Causes include viral, bacterial, and parasitic infections. Although outbreaks of foodborne illness are more often publicized, most cases are individual and not associated with an outbreak from a common source.2 Most of what is known about common-source outbreaks is from a small fraction of cases that are investigated by the Interagency Food Safety Analytics Collaboration formed by the Centers for Disease Control and Prevention (CDC), US Food and Drug Administration (FDA), US Department of Agriculture's Food Safety and Inspection Service, and state and local health authorities.3,4

SORT: KEY RECOMMENDATIONS FOR PRACTICE

Clinical recommendation Evidence rating Comments
Reduced osmolarity oral rehydration solution is recommended as first-line therapy for mild to moderate dehydration in patients with acute vomiting or diarrhea.14,19,27 B Consistent evidence from randomized controlled trials showing reduced morbidity and mortality
A single dose of ondansetron is recommended to maintain hydration in children with clinically significant vomiting from acute gastroenteritis.31 A Consistent evidence from a systematic review of randomized controlled trials
Empiric antibiotics should be reserved for patients with severe symptoms or high-risk comorbidities, including infants younger than 3 months with a suspected bacterial etiology; immunocompetent patients with fever, abdominal pain, bloody diarrhea, or abdominal cramps; those who recently traveled internationally and have fever or signs of sepsis; and immunocompromised individuals.14 C Consensus guidelines
Suspected outbreaks of foodborne illness should be reported to the local or state health department. Outbreaks are then reported and tracked through Centers for Disease Control and Prevention surveillance programs such as FoodNet and the National Outbreak Reporting System.4,39 C Expert opinion and consensus guidelines

FoodNet = Foodborne Diseases Active Surveillance Network.

A = consistent, good-quality patient-oriented evidence; B = inconsistent or limited-quality patient-oriented evidence; C = consensus, disease-oriented evidence, usual practice, expert opinion, or case series. For information about the SORT evidence rating system, go to https://www.aafp.org/afpsort.

According to the CDC, norovirus is one of the most common causes of confirmed, single-etiology outbreaks.5 Noroviruses are environmentally hardy and can be transmitted via food, water, person-to-person contact, and contact with contaminated surfaces. Concentrations of disinfectants that are commonly used against bacteria are not effective against noroviruses.6

ALEXIS REEDY-COOPER, MD, MPH, is an associate professor and department chair in the Department of Family and Community Medicine at Texas Tech Health Sciences Center El Paso, El Paso. At the time this article was written, she was an associate professor in the Department of Family and Community Medicine at Pennsylvania State University College of Medicine, Hershey, and program director in the Department of Family and Community Medicine at Penn State Health St. Joseph's Medical Center, Reading.

JUAN PEREZ, DO, is an assistant professor in the Department of Family and Community Medicine at Pennsylvania State University College of Medicine, Hershey, and core faculty in the Department of Family and Community Medicine at Penn State Health St. Joseph's Medical Center, Reading.

THERESA YURKONIS, DO, MHSA, is an assistant professor in the Department of Family and Community Medicine at Pennsylvania State University College of Medicine, Hershey, and core faculty in the Department of Family and Community Medicine at Penn State Health St. Joseph's Medical Center, Reading.

Address correspondence to Alexis Reedy-Cooper, MD, MPH, at areedyco@ttuhsc.edu.

Author Disclosure: No relevant financial relationships.

  1. 1.US Food and Drug Administration. What you need to know about foodborne illnesses. February 17, 2022. Accessed June 5, 2025. http://www.fda.gov/food/resourcesforyou/consumers/ucm103263.htm
  2. 2.Lipman DJ, Cherry JL, Strain E, et al. Genomic perspectives on foodborne illness. Proc Natl Acad Sci USA. 2024;121(46):e2411894121.
  3. 3.Ebel ED, Williams MS, Cole D, et al. Comparing characteristics of sporadic and outbreak-associated foodborne illnesses, United States, 2004–2011. Emerg Infect Dis. 2016;22(7):1193-1200.
  4. 4.Shah HJ, Jervis RH, Wymore K, et al. Reported incidence of infections caused by pathogens transmitted commonly through food: impact of increased use of culture-independent diagnostic tests—Foodborne Diseases Active Surveillance Network, 1996–2023. MMWR Morb Mortal Wkly Rep. 2024;73(26):584-593.
  5. 5.Centers for Disease Control and Prevention. Surveillance for foodborne disease outbreaks, United States, 2017: annual report. September 6, 2024. Accessed June 8, 2026. https://www.cdc.gov/fdoss/pdf/2017_FoodBorneOutbreaks_508.pdf
  6. 6.US Food and Drug Administration. Bad Bug Book. Handbook of Foodborne Pathogenic Microorganisms and Natural Toxins. 2nd ed. 2012. Accessed June 5, 2025. http://www.fda.gov/Food/FoodborneIllnessContaminants/CausesOfIllnessBadBugBook/
  7. 7.Bavishi C, Dupont HL. Systematic review: the use of proton pump inhibitors and increased susceptibility to enteric infection. Aliment Pharmacol Ther. 2011;34(11):1269-1281.
  8. 8.Lund BM, O'Brien SJ. The occurrence and prevention of foodborne disease in vulnerable people. Foodborne Pathog Dis. 2011;8(9):961-973.
  9. 9.Thomas MK, Murray R, Flockhart L, et al. Estimates of foodborne illness-related hospitalizations and deaths in Canada for 30 specified pathogens and unspecified agents. Foodborne Pathog Dis. 2015;12(10):820-827.
  10. 10.Centers for Disease Control and Prevention. 2019 antibiotic resistance threats report. April 11, 2025. Accessed June 5, 2025. https://www.cdc.gov/antimicrobial-resistance/data-research/threats/index.html
  11. 11.Bennett SD, Walsh KA, Gould LH. Foodborne disease outbreaks caused by Bacillus cereus, Clostridium perfringens, and Staphylococcus aureus—United States, 1998–2008. Clin Infect Dis. 2013;57(3):425-433.
  12. 12.Bhandari J, Thada PK, Hashmi MF, et al. Typhoid fever. StatPearls. Updated April 19, 2024. Accessed June 8, 2026. https://www.ncbi.nlm.nih.gov/books/NBK557513/
  13. 13.Kanungo S, Azman AS, Ramamurthy T, et al. Cholera. Lancet. 2022;399(10333):1429-1440.
  14. 14.Shane AL, Mody RK, Crump JA, et al. 2017 Infectious Diseases Society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea. Clin Infect Dis. 2017;65(12):e45-e80.
  15. 15.Brenner DM, Domínguez-Muñoz JE. Differential diagnosis of chronic diarrhea: an algorithm to distinguish irritable bowel syndrome with diarrhea from other organic gastrointestinal diseases, with special focus on exocrine pancreatic insufficiency. J Clin Gastroenterol. 2023;57(7):663-670.
  16. 16.Switaj TL, Winter KJ, Christensen SR. Diagnosis and management of foodborne illness. Am Fam Physician. 2015;92(5):358-365.
  17. 17.Giangaspero A, Gasser RB. Human cyclosporiasis. Lancet Infect Dis. 2019;19(7):e226-e236.
  18. 18.Ryan U, Hijjawi N, Xiao L. Foodborne cryptosporidiosis. Int J Parasitol. 2018;48(1):1-12.
  19. 19.Zubairi MBA, Naqvi SK, Ali AA, et al. Low-osmolarity oral rehydration solution for childhood diarrhoea: a systematic review and meta-analysis. J Glob Health. 2024;14:04166.
  20. 20.US Department of Health and Human Services; Office of Disease Prevention and Health Promotion. Healthy People 2030: foodborne illness. Accessed June 5, 2025. https://health.gov/healthypeople/objectives-and-data/browse-objectives/foodborne-illness
  21. 21.O'Horo JC, Harper EP, El Rafei A, et al. Efficacy of antitoxin therapy in treating patients with foodborne botulism: a systematic review and meta-analysis of cases, 1923–2016. Clin Infect Dis. 2017;66:S43-S56.
  22. 22.Langan RC, Goodbred AJ, Hepatitis A. Am Fam Physician. 2021;104(4):368-374.
  23. 23.Bazaco MC, Carstens CK, Greenlee T, et al. Recent use of novel data streams during foodborne illness cluster investigations by the United States Food and Drug Administration: qualitative review. JMIR Public Health Surveill. 2025;11:e58797.
  24. 24.Hartman S, Brown E, Loomis E, et al. Gastroenteritis in children. Am Fam Physician. 2019;99(3):159-165.
  25. 25.Flynn TG, Olortegui MP, Kosek MN. Viral gastroenteritis. Lancet. 2024;403(10429):862-876.
  26. 26.Yasmin N, Ruzante JM, Barkley JA, et al. Detection of gastrointestinal pathogens in stool samples using a rapid multiplex PCR test at a large tertiary pediatric hospital. Diagn Microbiol Infect Dis. 2024;110(4):116544.
  27. 27.Aghsaeifard Z, Heidari G, Alizadeh R. Understanding the use of oral rehydration therapy: a narrative review from clinical practice to main recommendations. Health Sci Rep. 2022;5(5):e827.
  28. 28.Freedman SB, Willan AR, Boutis K, et al. Effect of dilute apple juice and preferred fluids vs electrolyte maintenance solution on treatment failure among children with mild gastroenteritis: a randomized clinical trial. JAMA. 2016;315(18):1966-1974.
  29. 29.Sollanek KJ, Kenefick RW, Cheuvront SN. Osmolality of commercially available oral rehydration solutions: impact of brand, storage time, and temperature. Nutrients. 2019;11(7):1485.
  30. 30.Conlon CP. Food-borne diarrheal illness. In: Cohen J, Powderly WG, Opal SM, eds. Infectious Diseases. 4th ed. Elsevier; 2017: 328–334.
  31. 31.Fugetto F, Filice E, Biagi C, et al. Single-dose of ondansetron for vomiting in children and adolescents with acute gastroenteritis—an updated systematic review and meta-analysis. Eur J Pediatr. 2020;179(7):1007-1016.
  32. 32.Su GL, Ko CW, Bercik P, et al. AGA clinical practice guidelines on the role of probiotics in the management of gastrointestinal disorders. Gastroenterology. 2020;159(2):607-705.
  33. 33.World Health Organization. Zinc supplementation in the management of diarrhoea. Updated August 9, 2023. Accessed June 5, 2025. https://www.who.int/tools/elena/interventions/zinc-diarrhoea
  34. 34.Freedman SB, van de Kar NCAJ, Tarr PI. Shiga toxin-producing Escherichia coli and the hemolytic-uremic syndrome. N Engl J Med. 2023;389(15):1402-1414.
  35. 35.Holst MM, Wittry BC, Crisp C, et al. Contributing factors of foodborne illness outbreaks—National Outbreak Reporting System, United States, 2014–2022. MMWR Surveill Summ. 2025;74(1):1-12.
  36. 36.Insfran-Rivarola A, Tlapa D, Limon-Romero J, et al. A systematic review and meta-analysis of the effects of food safety and hygiene training on food handlers. Foods. 2020;9(9):1169.
  37. 37.Centers for Disease Control and Prevention. Norovirus fact sheet for food workers. May 8, 2024. Accessed November 14, 2025. https://www.cdc.gov/norovirus/communication-resources/facts-for-food-workers.html
  38. 38.Ballard SB, Requena D, Mayta H, et al. Enteropathogen changes after rotavirus vaccine scale-up. Pediatrics. 2022;149(1):e2020049884.
  39. 39.Wikswo ME, Roberts V, Marsh Z, et al. Enteric illness outbreaks reported through the National Outbreak Reporting System—United States, 2009–2019. Clin Infect Dis. 2022;74(11):1906-1913.

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