Foodborne outbreaks reported to national surveillance systems represent a subset of all outbreaks in the United States; not all outbreaks are detected, investigated, and reported. We described the structural factors and outbreak characteristics of outbreaks reported during 2009–2018. We categorized states (plus DC) as high (highest quintile), middle (middle 3 quintiles), or low (lowest quintile) reporters on the basis of the number of reported outbreaks per 10 million population. Analysis revealed considerable variation across states in the number and types of foodborne outbreaks reported. High-reporting states reported 4 times more outbreaks than low reporters. Low reporters were more likely than high reporters to report larger outbreaks and less likely to implicate a setting or food vehicle; however, we did not observe a significant difference in the types of food vehicles identified. Per capita funding was strongly associated with increased reporting. Investments in public health programming have a measurable effect on outbreak reporting.
Foodborne diseases remain a major public health challenge in the United States, where 31 known pathogens cause an estimated 9 million illnesses, 56,000 hospitalizations, and 1,300 deaths annually (1). Efforts to improve food safety and reduce the burden of foodborne disease rely on data from foodborne disease surveillance and outbreak investigations to help prioritize food safety interventions, policies, and practices. Data from foodborne illness outbreaks reported to the Centers for Disease Control and Prevention (CDC) provide vital information on the foods causing illness and common food–pathogen pairs. Those data are used by the Interagency Food Safety Analytics Collaboration (IFSAC) to inform outbreak-based attribution models that attribute illnesses to specific food categories (2,3).
Foodborne illness outbreaks are investigated by local, state, and territorial health departments, CDC, the US Food and Drug Administration (FDA), and the Food Safety and Inspection Service of the United States Department of Agriculture and are reported to CDC’s Foodborne Disease Outbreak Reporting Surveillance System (FDOSS) through the web-based National Outbreak Reporting System (NORS). Although reported outbreaks are a rich data source, they represent a subset of all outbreaks occurring in the United States; not all outbreaks will be detected, investigated, and reported. Factors influencing which outbreaks are detected, investigated, and reported to CDC include both structural factors associated with the jurisdiction in which the outbreak occurred (e.g., infrastructure and capacity) and characteristics of the outbreak (e.g., size, geographic location, pathogen).
We integrated data from a variety of sources to examine structural factors and describe outbreak characteristics of foodborne outbreaks involving Salmonella, Shiga toxin–producing Escherichia coli (STEC) O157, norovirus, and bacterial toxins that were reported to national surveillance. In addition, we assessed the effects of state variation in outbreak reporting on the types of food vehicles identified.