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FoodNet (Foodborne Diseases Active Surveillance Network) is a collaborative active surveillance network conducted by the CDC, ten state health departments, USDA-FSIS, and the FDA. Covering roughly 15% of the United States population, FoodNet tracks laboratory-diagnosed enteric infections to measure disease burden, evaluate food safety interventions, and track longitudinal public health trends.
Short answer
FoodNet is the premier active surveillance collaborative tracking foodborne and enteric infections across ten designated United States sites. Established under the CDC’s Emerging Infections Program, FoodNet actively contacts clinical laboratories to identify cases, measure disease incidence for eight major pathogens, evaluate food safety interventions, and benchmark progress toward national health reduction targets.
Definition and scope
Established in 1996 under the CDC’s Emerging Infections Program (EIP), the Foodborne Diseases Active Surveillance Network (FoodNet) provides the epidemiological foundation for monitoring enteric infections in the United States. Unlike passive reporting systems, FoodNet operates as an active, population-based surveillance network administered through a partnership between the CDC, the USDA Food Safety and Inspection Service (USDA-FSIS), the Food and Drug Administration (FDA), and state health departments across ten participating states.
The FoodNet catchment area covers Connecticut, Georgia, Maryland, Minnesota, New Mexico, Oregon, and Tennessee, and selected counties in California, Colorado, and New York. Historically representing roughly 15% of the United States population, FoodNet expanded its catchment boundaries in 2023 to enhance demographic and geographic representativeness. FoodNet conducts surveillance for laboratory-diagnosed infections caused by eight enteric pathogens:
- Campylobacter
- Cyclospora cayetanensis
- Listeria monocytogenes
- Salmonella
- Shiga toxin-producing Escherichia coli (STEC)
- Shigella
- Vibrio
- Yersinia enterocolitica
FoodNet also actively tracks postdiarrheal Hemolytic Uremic Syndrome (HUS)—a severe renal complication primarily triggered by pediatric STEC infection—through pediatric nephrologists and hospital record reviews.
How it works or how it is used in practice
FoodNet operates through an active surveillance protocol. While conventional reporting systems like the National Notifiable Diseases Surveillance System (NNDSS) rely on healthcare facilities to voluntarily submit case reports, FoodNet personnel regularly contact all clinical diagnostic laboratories within the catchment area to identify every laboratory-confirmed case.
Surveillance officers conduct routine audits of participating laboratories, verifying logbooks, electronic health feeds, and LIMS records against notifications to ensure complete case ascertainment.
These data feed into the CDC’s foodborne disease burden framework (Scallan et al., 2011), which models the five-tiered “surveillance pyramid”:
- Exposure and illness: General population members exposed to contaminated food who develop gastroenteritis.
- Care seeking: Symptomatic individuals who consult a healthcare provider.
- Specimen submission: Clinicians who order stool tests and patients who provide specimens.
- Laboratory testing: Diagnostic laboratories that identify the organism.
- Surveillance ascertainment: Confirmed cases recorded by FoodNet surveillance officers.
Because most ill individuals do not seek medical care or submit stool specimens, laboratory diagnoses capture only a fraction of total illnesses. CDC epidemiologists apply FoodNet population multipliers to calculate that 31 major pathogens cause an estimated 9.4 million foodborne illnesses, 56,000 hospitalizations, and 1,350 deaths annually in the United States. To evaluate progress toward HHS Healthy People 2030 targets, FoodNet applies Bayesian negative binomial models to adjust for demographic shifts relative to the 2016–2018 baseline.
Types or related concepts
FoodNet functions as a core component within the federal enteric disease surveillance architecture. Its role is distinct from complementary public health systems.
| Surveillance Network | Lead Agencies | Surveillance Type | Geographic Scope | Methodological Focus | Primary Output |
|---|---|---|---|---|---|
| FoodNet | CDC, USDA-FSIS, FDA, 10 states | Active population-based surveillance | 10 EIP sites (~15% of US population) | Laboratory audits and direct case ascertainment | Population incidence, disease burden multipliers, Healthy People benchmarks |
| PulseNet | CDC, state and local public health laboratories | Laboratory molecular surveillance | Nationwide (50 states) | Whole genome sequencing (WGS) of bacterial isolates | Outbreak cluster detection and multi-state outbreak tracking |
| NNDSS | CDC, state and territorial health departments | Passive jurisdictional reporting | Nationwide (all US jurisdictions) | Mandatory notifiable disease case reporting | National annual summaries and broad jurisdictional counts |
| FDOSS | CDC, state and local health departments | Outbreak event reporting | Nationwide | Investigation of discrete outbreak clusters | Food vehicle attribution and implicated commodity data |
In this architecture, FoodNet operates as a specialized sentinel surveillance system. Whereas PulseNet identifies specific outbreak clusters and NNDSS compiles broad jurisdictional counts, FoodNet measures true population incidence and monitors whether national interventions successfully reduce illness over time.
Where it matters for labs, clinics or supply decisions
FoodNet data and workflows directly shape clinical diagnostics, laboratory operations, and federal food safety regulations.
The CIDT Surveillance Transition
Clinical diagnostic laboratories have largely transitioned from bacterial culture to culture-independent diagnostic tests (CIDTs), including multiplexed PCR panels and antigen detection assays. These qualitative diagnostic tests deliver rapid results without requiring selective bacterial growth.
However, CIDTs introduce a surveillance challenge. According to CDC surveillance findings (Collins et al., 2024), CIDTs identify milder infections that previously went undetected, producing an apparent increase in reported incidence for pathogens like Campylobacter and STEC. Furthermore, because laboratories do not require live bacteria to diagnose an infection, isolate recovery rates have declined: in 2023, only 57% of STEC infections and 83% of Salmonella infections reported to FoodNet yielded an isolate.
Reflex Culturing and Public Health Forwarding
To preserve genomic epidemiology, state regulations in FoodNet jurisdictions require clinical laboratories to perform reflex cultures or forward positive specimens to state public health laboratories (PHLs). Live bacterial isolates remain essential for isolate surveillance and genomic sequencing. Public health laboratories perform whole genome sequencing (WGS) and antimicrobial susceptibility testing (AST) to identify outbreak clusters in PulseNet and track resistance patterns in the National Antimicrobial Resistance Monitoring System (NARMS).
Regulatory Impact and Performance Standards
FoodNet surveillance directly informs federal regulatory standards. USDA-FSIS relies on FoodNet incidence and attribution data to update pathogen reduction performance standards for commercial meat and poultry slaughter establishments. Similarly, the FDA utilizes FoodNet metrics to evaluate regulations established under the Food Safety Modernization Act (FSMA), including the Produce Safety Rule.
Common misunderstandings
Public health professionals and researchers frequently encounter several misconceptions regarding FoodNet:
- FoodNet is an acute outbreak response team: FoodNet does not conduct rapid field investigations of foodborne outbreaks. Point-source outbreak investigations are handled by state epidemiologists and PulseNet. FoodNet tracks baseline incidence, national burden, and long-term trends.
- Higher FoodNet counts always reflect worsening food contamination: Recent increases in reported rates of campylobacteriosis, yersiniosis, and STEC primarily reflect the sensitivity and rapid uptake of multiplex PCR panels rather than true surges in contamination.
- FoodNet covers all fifty states: FoodNet is an active sentinel surveillance system across ten states (~15% of the US population), not a universal national registry. Its intensive ascertainment methods provide high-quality data representative of the national population.
- FoodNet only monitors food-related bacterial infections: FoodNet tracks the parasite Cyclospora cayetanensis and severe postdiarrheal complications like pediatric HUS. Monitored pathogens can also be transmitted through animal contact, water, and person-to-person spread.
Frequently asked questions
What is the difference between active surveillance and passive surveillance?
In passive surveillance, health agencies wait for clinicians and diagnostic laboratories to submit case reports. In active surveillance, such as FoodNet, public health investigators routinely contact all laboratories in the catchment area and audit records to identify every confirmed infection.
How does FoodNet differ from PulseNet?
FoodNet tracks epidemiological incidence, hospitalizations, and national disease burden across 10 defined sites. PulseNet is a nationwide laboratory network across all 50 states that performs whole genome sequencing on bacterial isolates to detect and investigate outbreak clusters.
What pathogens are routinely tracked by FoodNet?
FoodNet actively tracks laboratory-diagnosed infections caused by eight pathogens: Campylobacter, Cyclospora, Listeria, Salmonella, Shiga toxin-producing Escherichia coli (STEC), Shigella, Vibrio, and Yersinia, along with postdiarrheal Hemolytic Uremic Syndrome (HUS).
How do culture-independent diagnostic tests (CIDTs) affect FoodNet data?
CIDTs detect pathogen DNA or antigens without culture, increasing reported incidence while reducing the recovery of viable isolates needed for serotyping and whole genome sequencing.
Sources
- Collins JP, Shah HJ, Weller DL, 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):582–588. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11221634/ (Accessed November 9, 2026).
- Danielson ML, Manikonda N, Palmer A, et al. Preliminary Incidence and Trends of Infections Caused by Pathogens Transmitted Commonly Through Food — Foodborne Diseases Active Surveillance Network, 10 U.S. Sites, 2022. MMWR Morb Mortal Wkly Rep. 2023;72(26):701–706. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10328488/ (Accessed November 9, 2026).
- Scallan E, Hoekstra RM, Angulo FJ, et al. Foodborne illness acquired in the United States—major pathogens. Emerg Infect Dis. 2011;17(1):7–15. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3375761/ (Accessed November 9, 2026).
