[1] Univ Geneva Hosp, Geneva, Switzerland
[2] Fac Med, Geneva, Switzerland
[3] Univ Hosp Bonn, Inst Hyg & Publ Hlth, Bonn, Germany
[4] Univ Geneva Hosp, Infect Control Programme, Geneva, Switzerland
[5] Univ Geneva Hosp, WHO Collaborating Ctr Patient Safety, Geneva, Switzerland