Occupational Exposure to Dust and to Fumes, Work As a Welder and Invasive Pneumococcal Disease Risk

Background: Occupational exposures to metal fumes and inorganic dust have been associated with increased pneumonia risk, but the risk of invasive pneumococcal disease (IPD) has not been characterized previously. Methods: We studied 4 438 cases 20 to 65 years of age from a Swedish national registry of invasive infection caused by Streptococcus pneumoniae. The case index date was the day the infection was diagnosed. Six controls for each case, matched for gender and age, 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, hospital discharge and mortality. We applied a job-exposure matrix (JEM) to characterize occupational exposures. We used conditional logistic analyses, adjusted for co-morbidities and SES, to estimate the odds ratio (OR) of IPD and the subgroup with pneumonia, associated with selected occupations and exposures the year before index date. Results: Welders manifested increased risk of IPD (OR 2.99, 95% confidence interval (CI) 2.09 - 4.30). Occupations likely to have exposure to fumes based on a JEM-assignment were also associated with elevated odds of IPD (OR 2.40, 95% CI 1.72-3.36). Risk associated with IPD with pneumonia followed a similar pattern with the highest occupational odds observed among welders (OR 3.28, 95% CI 2.22-4.84). Conclusions: Work as welder and occupational exposure to fumes increase the odds for IPD. Welders and potentially others with relevant exposures should be offered pneumococcal vaccination. Funding Statement: Swedish Heart and Lung Foundation, Swedish Council for Working Life, Health, and Welfare (FORTE) and by grants from the Swedish state under the agreement between the Swedish government and the county councils, the ALF-agreement, 74570. Declaration of Interests: All authors have completed the Unified Competing Interest form at www.icmje/coi_disclosure.pdf (available in request from the corresponding author): KT, IQ, OA, NM, RN, ADH, PDB and LS do not have any conflict of interest to report. Ethical Approval Statement: The Gothenburg Committee of Ethics approved the study (Dnr 729-16).