Can legionellosis be considered an occupational risk in the healthcare sector? A systematic review and meta-analysis.

OBJECTIVES

According to current knowledge about legionella transmission, healthcare workers (HCWs) are at an increased risk of exposure. The aim of this research was to systematically review the literature about HCWs' exposure to legionella and establish whether there is an occupational risk.

STUDY DESIGN

This was a systematic review and meta-analysis.

METHODS

PubMed, Scopus and Web of Science were searched to identify studies regarding the occupational risk of legionellosis for HCWs. Keywords used in the search were 'Legionella pneumophila', 'occupational medicine', 'occupational' and 'risk'. Selected studies were reviewed to assess the quality and meta-analysed. Finally, the nine epidemiological principles of Bradford-Hill criteria were used to assess whether legionellosis could be considered an occupational risk for HCWs.

RESULTS

The search strategy retrieved 124 studies, and 10 studies were included in the present review. The overall study quality was low. The pooled odds ratio estimate was 2.45 (95% confidence interval: 1.52-3.96). The assessment using Bradford-Hill criteria showed that only two criteria (plausibility and coherence) were met, which is insufficient to establish an occupational risk.

CONCLUSIONS

This systematic review suggests that there is a higher risk of legionella exposure for HCWs, but there is currently no clinical evidence. Further studies with appropriate study design are needed to determine whether legionella infection is an occupational risk for HCWs.