Occupational exposure to dust and to fumes, work as a welder and invasive pneumococcal disease risk.

Objectives: Occupational exposures to metal fumes have been associated with increased pneumonia risk, but the risk of invasive pneumococcal disease (IPD) has not been characterised previously.

Methods: We studied 4438 cases aged 20-65 from a Swedish registry of invasive infection caused by . The case index date was the date the infection was diagnosed. Six controls for each case, matched for gender, age and region of residency, were selected from the Swedish population registry. Each control was assigned the index date of their corresponding case to define the study observation period. We linked cases and controls to the Swedish registries for socioeconomic status (SES), occupational history and hospital discharge. We applied a job-exposure matrix to characterise occupational exposures. We used conditional logistic analyses, adjusted for comorbidities and SES, to estimate the OR of IPD and the subgroup pneumonia-IPD, associated with selected occupations and exposures in the year preceding the index date.

Results: Welders manifested increased risk of IPD (OR 2.99, 95% CI 2.09 to 4.30). Occupational exposures to fumes and silica dust were associated with elevated odds of IPD (OR 1.11, 95% CI 1.01 to 1.21 and OR 1.33, 95% CI 1.11 to 1.58, respectively). Risk associated with IPD with pneumonia followed a similar pattern with the highest occupational odds observed among welders and among silica dust exposed.

Conclusion: Work specifically as a welder, but also occupational exposures more broadly, increase the odds for IPD. Welders, and potentially others with relevant exposures, should be offered pneumococcal vaccination.