World Health Organization attribution of burden of foodborne diseases to transmission pathways and foods

Identifying the sources of foodborne diseases is crucial for guiding national food safety strategies and supporting policies that promote safe and sustainable food production. Here we present global estimates of the proportions of burden of disease attributable to foodborne transmission, other major transmission pathways, and specific food categories for 29 viral, bacterial, parasitic, and chemical hazards, based on a structured expert judgement (SEJ) study commissioned by the World Health Organization (WHO) and supervised by the WHO Foodborne Disease Burden Epidemiology Reference Group (FERG) for 2021-2025. One-hundred forty-six experts provided 1463 assessments across 17 subregions within six WHO regions. The assessments were analyzed using Cooke's Classical Model and reviewed by FERG. Results showed that 13 of the 29 hazards were mainly (>50%) attributable to foodborne transmission, with non-typhoidal Salmonella (59-74%) and Campylobacter (45-71%) estimated to be predominantly foodborne in nearly all subregions. While plant-based foods were important sources of several pathogens, such as hepatitis A virus (63-74%) and Cryptosporidium (60-95%), foods of animal origin, including poultry, beef, eggs, seafood, and dairy products, remain critical intervention targets for several others, e.g., Campylobacter (86-97%), Salmonella (77-92%), Shiga toxin-producing E. coli (67-96%), and Listeria monocytogenes (50-85%). Regional differences in attributions highlight the influence of local epidemiological patterns, food systems, sanitation, and cultural practices. These estimates provide a global, uncertainty-quantified knowledge base to guide context-specific food safety interventions and future empirical data collection. Given persistent data gaps, SEJ remains a feasible approach to generate evidence supporting efforts to reduce the burden of foodborne diseases.