Campylobacteriosis incidence across the United States rose steadily over a decade-long period spanning from 2004 to 2023, according to a study published in the journal Zoonoses. Researchers analyzed data from three major federal surveillance networks—the Foodborne Diseases Active Surveillance Network (FoodNet), the National Notifiable Diseases Surveillance System (NNDSS), and the National Outbreak Reporting System (NORS)—to map the changing epidemiology of the bacterial infection.
Comparing Surveillance Data Across FoodNet and NNDSS Networks
FoodNet conducts active surveillance across 10 specific U.S. sites, while NNDSS manages national passive surveillance, and NORS captures data on foodborne outbreaks. According to the study by D.L. Weller and colleagues, the clinical and patient characteristics of illnesses reported to FoodNet and NNDSS closely mirrored each other throughout the study period. Both systems tracked a sustained increase in campylobacteriosis incidence that began in 2010, showing increasing concordance after 2015.
The findings indicate that NNDSS data can reliably support the monitoring of national campylobacteriosis trends. The parallel trajectories recorded by both the active network in FoodNet and the passive tracking in NNDSS give public health officials confidence in using broader national datasets for tracking the disease.
Drivers of Rising Campylobacteriosis Rates
The adoption of culture-independent diagnostic tests (CIDT) drove some of the increase in reported campylobacteriosis incidence between 2004 and 2023, but testing changes cannot fully explain the upward trend. Diagnostic shifts often catch more mild cases that older methods missed, yet the sustained rise points to actual changes in disease frequency.
Outbreak frequency remained remarkably stable across the 2004–2023 study period. However, the average size of those outbreaks decreased. Because outbreaks did not grow larger or more frequent, researchers concluded that the overall increase in campylobacteriosis incidence was driven primarily by sporadic illnesses rather than large outbreak events.
Frequently Asked Questions About Campylobacteriosis Surveillance
Which surveillance systems monitor campylobacteriosis in the United States?
The U.S. relies on FoodNet for active surveillance across 10 sites, NNDSS for national passive surveillance, and NORS to capture data specifically on outbreaks.
What caused the increase in reported campylobacteriosis cases between 2004 and 2023?
The adoption of culture-independent diagnostic tests contributed to the rise, but researchers found it cannot fully explain the sustained increase, pointing instead to a growth in sporadic, non-outbreak illnesses.
Did outbreak sizes grow larger during the study period?
No. While overall campylobacteriosis incidence climbed, outbreak frequency stayed stable and the average size of individual outbreaks actually decreased between 2004 and 2023.
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