Silver-Containing Polymers

We read with interest about the investigations of Kampf et al. (2) concerning the antimicrobial activity of a new silver-containing polymer. The use of silver may be regarded as an effective non-resistance-inducing strategy to prevent device-related infections. In vitro and in vivo experiments have been performed during the recent years to develop potent antimicrobially acting silver-coated devices. Most of the authors claimed strong antimicrobial efficacy of silver-coated devices, and the industry launched several products on the market. However, randomized clinical studies showing statistically significant antimicrobial efficacy of silver-coated medical devices in high-risk populations of patients are rare, dealt with small numbers of patients only, and are controversial (6). The largest randomized controlled clinical study with 1,300 patients revealed no significant differences in infection rates between silver-coated and unmodified catheters (4), a finding which is in accordance with the observations made by Kampf et al. (2).