1 Infection Prevention and Control Global Unit, Service Delivery and Safety, World Health Organization, 1211 Geneva 27, Switzerland. Electronic address: allegranzib@who.int.
2 Bolzano Central Hospital, Bolzano, Italy; Annecy-Genevois Hospital Centre, Epagny Metz-Tessy, France.
3 Department of Surgery, Academic Medical Center Amsterdam, Amsterdam, Netherlands.
4 Infection Control Programme and World Health Organization Collaborating Centre on Patient Safety (Infection Control and Improving Practices), University of Geneva Hospitals and Faculty of Medicine, Geneva, Switzerland.