Acknowledgements
All listed authors declare no financial support, grants, financial interests or consultancy that could lead to conflicts of interest. Preliminary results have been presented at the 3rd International Conference of Prevention and Infection Control (ICPIC), 16–19 June 2015, Geneva, Switzerland, and at the Annual Meeting of the Swiss Society for Infectious Diseases, 2–4 September 2015, Interlaken, Switzerland.
Disclosure statement
The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.