Epidemiology of occupational hypersensitivity pneumonitis in the UK: an update from the SWORD scheme

<bold>Background:</bold> Causative exposures are key to diagnosis and prognosis in hypersensitivity pneumonitis. Occupational exposures contribute significantly to disease burden (occupational HP or OHP). <bold>Methods:</bold> Actual and estimated cases of OHP reported to the SWORD scheme were identified between January 2016 and December 2022. Exposures were classified into 10 categories based on causative agent. The incidence of OHP was estimated using number of UK working adults from midpoint 2019 ONS employment data. <fig><object-id>erj;64/suppl_68/PA1306/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig> <bold>Results:</bold> Fifty-eight actual (124 estimated) cases of OHP were reported. The incidence across the period was 1.77 cases per million workers. Cases had a mean age of 55.66 (SD 11.78) yrs, and 72% were men. Half (47%) were employed in manufacturing, followed by agriculture/forestry/fishing (17%). The commonest occupational groups were skilled trades (45%) and process, plant and machine operatives (17%): the commonest single group was metal machining (28%). Leading causative agents were fungi/moulds (24%), metalworking fluids (21%), and avian proteins (21%) (figure 1). One case was reported secondary to an unknown exposure. <bold>Conclusions:</bold> Estimated incidence of OHP is broadly stable in the UK although the true incidence of OHP is unknown. Metalworking fluids accounted for fewer, and avian and fungal exposure more, cases versus 2016 data. Alongside farming exposures these remain leading causes of OHP in the UK.