A helpful new review and meta-analysis asks whether treating hard surfaces or linen reduces healthcare-associated infections. The review identified only a small number of studies that had both a copper-related intervention related to surfaces and/or linen and an outcome related to HCAI. But the meta-analysis of the seven studies found that, overall, the risk of HCAI was reduced by 27% (risk ratio 0.73, 95% confidence interval 0.57–0.94).
The idea of copper to reduce infection is far from new – and has a history stretching back millennia. Copper is an attractive candidate antimicrobial surfaces because it has a broad range of antimicrobial activity (including some sporicidal activity) and is fairly rapid too. However, it has important operational challenges (e.g. cost, feasibility of application, and patient/staff acceptability). These drawbacks would seem less important if only there was solid data that introducing copper surfaces/textiles reduced HCAI.
And so to this new review and meta-analysis. The team asked whether controlled trials comparing the effect of copper-treated surfaces or bed linen in hospital rooms reduced the rate of HCAI. Searches identified only seven studies, and three were randomised. Four of the studies investigated copper-treated surfaces, two copper-treated textiles, and one both copper-treated surfaces and textiles.
As ever, one forest plot doesn’t tell the whole story of a systematic review and meta-analysis, but the overall finding was that copper-treated surfaces and/or textiles reduces the risk of HCAI by 27%. All of the studies showed that copper reduced HCAI to some degree or another.
The scale of the overall reduction is interesting. If we are to believe that introducing copper treated surfaces/textiles reduces the risk of HCAI by about a quarter, then the implication is that a quarter of HCAI are related, directly or indirectly, to contamination of surfaces/textiles. This is considerably more than you might expect, but maybe not surprising. We know that there is a dynamic interplay between contaminated surfaces and contaminated hands – in this way, hands are just another surface that can be involved in transmission; and one that is highly mobile and not often disinfected! Some of the studies had some fairly significant methodological weakness, but the overall picture is that copper treated surface/textiles may have an impotent protective effect against HCAI.