Carlotta Di Bari

Background: Foodborne diseases cause substantial global morbidity and mortality, yet remain largely unattended. To support countries to address this public health concern, the World Health Assembly Resolution 73.5 called for strengthening global food safety efforts and led to the development of the WHO Global Strategy for Food Safety 2022–2030, adopted at the 75th WHA (2022). To this end, the World Health Organization (WHO) reconvened the Foodborne Disease Burden Epidemiology Reference Group (FERG) to advise and support the work to generate updated global, regional, and national estimates of the foodborne disease burden for the reference period 2000–2021. Methods: We developed an incidence-based framework expanding coverage to 42 foodborne hazards. Standardized systematic reviews, Global Health Estimates and Global Burden of Disease envelopes, and United Nations population data informed the evidence base. Missing epidemiological data were imputed using Bayesian hierarchical meta-regression models. Disease models mapped acute and chronic health outcomes, applying updated disability weights, life tables, and probabilistic Monte Carlo calculations to estimate incidence, mortality, Years Lived with Disability, Years of Life Lost and Disability-Adjusted Life Years for all 194 WHO Member States. Transparency and analysis reproducibility were ensured through availed open source R packages and standardized workflows. Results: The computational framework provides annual, country-level estimates with improved internal consistency and an expanded hazard scope compared with the WHO 2015 edition. Advances include refined modelling, enhanced uncertainty propagation, and broader inclusion of microbial, parasitic, and chemical hazards. Persistent data gaps—especially in high-burden regions—were filled through extensive imputation. Conclusions: The computational framework for the WHO 2026 edition delivers the most comprehensive and transparent assessment of the global burden of foodborne diseases to date. Despite remaining limitations, it enables routine monitoring, supports evaluation of global food safety efforts, and highlights priorities for strengthening national data systems.

Diarrheal disease is caused by diverse species of viruses, bacteria and protozo that are transmitted from different sources, including from contaminated food. Sustaining progress in reducing diarrheal illnesses and deaths, including vaccines and food safety measures, may require interventions targeting specific pathogens. In 2015, the WHO’s published etiology-specific estimates by their Foodborne Disease Burden Epidemiology Reference Group (FERG) of the incidence and mortality of diarrheal diseases caused by 11 pathogens at global and regional scales in 2010. Since then, much new evidence has been published about the epidemiology of enteropathogens. This study aims to update estimates to the year 2021 with the addition of three pathogens (Rotavirus, Cyclospora cayetanensis , Enteroaggregative E. coli (EAEC)). For low- and middle-income countries (LMICs), we conducted a systematic review of publications that reported the prevalence of pathogens diagnosed in stool samples from asymptomatic subjects, community-detected and outpatient diarrhea cases, and those treated as inpatients. Hierarchical, mixed effects models were fitted to pathogen-specific prevalence data extracted from studies that met prespecified inclusion criteria, and population attributable fractions (PAF) were calculated from the model parameter estimates, adjusting for background asymptomatic transmission where appropriate. The PAFs were applied to previously estimated diarrhea incidence and mortality envelopes. A separate, parallel systematic review identified studies that estimated diarrhea incidence and mortality due to specific etiologies for high income countries (HICs) from surveillance data. Meta-analytical models were fitted to data extracted from these. Data from 324 studies published between 1990 and 2023 representing results from up to 540,000 samples were used in the meta-analysis. Globally the 14 pathogens were responsible for 2.2 billion diarrheal disease cases and 880,000 deaths in 2021, with the largest number of cases occurring in South-East Asia, the largest number of deaths in Sub-Saharan Africa, and Europe being the region with the lowest burden by both measures. We found the leading causes of diarrhea morbidity to be bacteria – Shigella (426.4 million cases in 2021), Campylobacter (291.4 million) and ETEC (259.7 million)) – as well as the protozoon Giardia (321.2 million), in contrast to previous studies that have ranked rotavirus and norovirus highest. Our estimates support a much higher morbidity burden for Shigella than previously estimated with an incidence rate for 2021 (5,400 per 100,000). This is due to its high PAF in outpatients aged ≥5 years. As causes of diarrhea mortality, our estimates rank rotavirus first (214,700 deaths in 2021), Shigella second (152,500), and V. cholerae (94,100) third, due to the latter’s large PAF in inpatients aged ≥5 years and high case fatality rate. Caution is urged when interpreting PAFs for pathogens that elicit prolonged residual shedding following resolution of symptoms (e.g., norovirus, Campylobacter , Giardia ). These findings, derived from rigorous systematic review and statistical methodologies and the largest database yet compiled of pathogen detection rates, will serve as inputs for the WHO’s broader estimates of hazard-specific incidence and mortality from foodborne diseases and are made available to the research and policy-making communities to inform targeted strategies for global diarrheal disease control. Funding: WHO EDTF_001; 1K01AI168493-01A1; K43TW012298; 5T32AI007046-48.

Background: Campylobacteriosis is a major zoonotic and foodborne disease (FBD), posing a substantial social and health economic burden on human health. Burden of disease (BoD) studies, which increasingly use the disability-adjusted life years (DALYs) metric, provide comprehensive insights into disease effects. However, the complexity of DALY calculations, combined with diverse causative agents and research gaps, complicates cross-regional comparisons. This review evaluates existing Campylobacter BoD studies and interrogates their methodological approaches and assumptions in quantifying DALYs. Methods/Principal Findings: A systematic search of PubMed, EMBASE, Web of Science, and selected grey literature databases was conducted to identify existing Campylobacter BoD studies. Studies assessing the BoD methodology and calculation using the DALY framework were considered. In total, 23 studies met the predefined inclusion criteria. Of these, 19 were single-country studies, while 4 were multi-country analyses. A significant data gap exists, with limited or no studies from low- and middle-income countries, exemplified by just one study obtained from Rwanda. Most studies used an incidence- and pathogen-based approach to estimate DALYs, excluding social weighting, in line with the Global Burden of Disease (GBD) study. Methodological discrepancies were noted, especially in disability weight (DW) assignment, health state classification, and life expectancy table usage. Most single-country studies (n=8) used national life tables rather than universal ones, challenging cross-country comparisons due to a lack of standardisation. Conclusion: Significant variations in the methodological approaches and assumptions for Campylobacter BoD studies exist. Addressing these disparities is essential for harmonising methodological design choices using the DALYs metric to inform evidence-based public health policies and interventions. PROSPERO Registration Number: The protocol for this study was registered with the International Prospective Register of Systematic Reviews (PROSPERO), which can be accessed under the registration number CRD42023414973 .

Zoonoses, diseases naturally transmitted between vertebrates and humans, represent significant global health threats. These diseases not only affect human health but also impose a considerable burden on animal populations, emphasizing the need for a One Health approach that integrates strategies across human, animal, and environmental health sectors. The socioeconomic impacts of zoonoses are profound in low- and middle-income countries, disrupting production systems, impacting livelihoods, and compromising food security. Populations in these regions are excessively affected, highlighting the urgent need for a comprehensive approach. The disability-adjusted life year (DALY) quantifies disease burden in terms of morbidity and mortality. The zoonotic DALY (zDALY) expands this metric by incorporating the burden on animals through the ‘animal loss equivalents’, accounting for both fatal and non-fatal outcomes in livestock. However, zDALYs do not encompass broader economic impacts associated with prevention and treatment. Cost of illness (COI) studies further quantify the financial costs due to health issues; ad hoc approaches can be used to quantify other costs related to animal disease control and eradication, trade and movement Implications, or loss of consumer confidence. While few zoonoses, such as cystic echinococcosis and brucellosis, have comprehensive data across these metrics, most do not. While these metrics provide complementary insights, no holistic metric currently encompasses all necessary aspects to fully assess the burden of zoonoses within a One Health framework. This presentation aims to offer state-of-the-art estimates of the disease burdens of zoonoses, employing DALY, zDALY, and COI studies. It will explore how to integrate these metrics from a One Health perspective. Indeed, only by integrating health and economic metrics that consider the well-being of humans and animals, can the One Health approach effectively be developed for zoonotic diseases.