Expanding AMR surveillance with the WHO’s AWaRe classification: a nationwide occupational cohort study in Taiwan (2004–2020)

Introduction: Bacterial infections and antibiotic resistance pose a growing global health threat. Current occupational risk surveillance is fragmented, focusing primarily on healthcare workers and neglecting other occupations like animal husbandry and agriculture. This study aimed to develop a novel surveillance method by applying the WHO's AWaRe (Access, Watch, Reserve) antibiotic classification to a nationwide retrospective insurance claims cohort. Hereby comprehensively assessing and identifying at-risk occupational settings and vulnerable workers for potentially resistant bacterial infections. Method: Using large claims databases in Taiwan, an occupational cohort was constructed with over 4 million workers spanning 16 years. Bacterial infections were identified, and potential antimicrobial resistance was indicated based on the AWaRe classification of prescribed antibiotics. Cox regression for recurrent events was used to assess occupational risk for infections treated with 'Reserve' and/or 'Watch' antibiotics, indicating potential resistance. Results: The analysis identified almost 25 000 Reserve events and over 31 million Reserve and/or Watch events, and revealed significantly elevated risks for potentially resistant bacterial infections for certain workers. In the agricultural sector, vegetable and crop cultivators exhibited elevated HRs for possibly resistant bacterial infections treated with Reserve antibiotics, with a risk of respectively 1.49 (95% CI 1.41 to 1.58) and 1.48 (95% CI 1.44 to 1.51) times larger compared with the reference group. Within healthcare, for the same resistance scenario, workers in residential care services faced a substantially higher risk for potentially resistant infections, with an adjusted HR of 2.21 (95% CI 2.04 to 2.40). Conclusions: The proposed passive surveillance method, using claims data and the AWaRe classification, offers a valuable and scalable tool for identifying and monitoring high-risk occupations, informing targeted interventions and improving worker protection globally. The findings indicate that specifically workers in vegetable and crop cultivation and residential care services in Taiwan are more prone to potentially resistant bacterial infections and in need of enhanced infection prevention.