[1] Tel Aviv Univ, Tel Aviv Sourasky Med Ctr, Div Epidemiol & Prevent Med, IL-69978 Tel Aviv, Israel
[2] Israel Minist Hlth, Natl Ctr Infect Control, Tel Aviv, Israel
[3] Univ Hosp Geneva, Div Infect Dis, Geneva, Switzerland
[4] Univ Hosp Geneva, Infect Control Program, Geneva, Switzerland
[5] Univ Geneva, Sch Med, CH-1211 Geneva, Switzerland