Foodborne Illnesses from Leafy Greens in the United States: Attribution, Burden, and Cost

Leafy green vegetables are a major source of foodborne illnesses. Nevertheless, few studies have attempted to estimate attribution and burden of illness estimates for leafy greens. This study combines results from three outbreak-based attribution models with illness incidence and economic cost models to develop comprehensive pathogen-specific burden estimates for leafy greens and their subcategories in the United States. We find that up to 9. 18% (90% CI: 5. 81%-15. 18%) of foodborne illnesses linked to identified pathogens are attributed to leafy greens. Including 'Unknown' illnesses not linked to specific pathogens, leafy greens account for as many as 2, 307, 558 (90% CI: 1, 077, 815-4, 075, 642) illnesses annually in the United States. The economic cost of these illnesses is estimated to be up to 5. 278 billion (90% CI: 3. 230-8. 221 billion) annually. Excluding the pathogens with small outbreak sizes, Norovirus, Shiga toxin-producing Escherichia coli (both non-O157 and O157: H7), Campylobacter spp. , and nontyphoidal Salmonella, are associated with the highest number of illnesses and greatest costs from leafy greens. While lettuce (romaine, iceberg, "other lettuce") takes 60. 8% of leafy green outbreaks, it accounts for up to 75. 7% of leafy green foodborne illnesses and 70% of costs. Finally, we highlighted that 19. 8% of Shiga toxin-producing Escherichia coli O157: H7 illnesses are associated with romaine among all food commodities, resulting in 12, 496 estimated illnesses and 324. 64 million annually in the United States.