[1] Royal Prince Alfred Hosp, Dept Infect Dis, Missenden Rd, Sydney, NSW 2050, Australia
[2] Royal Prince Alfred Hosp, Dept Microbiol, Missenden Rd, Sydney, NSW 2050, Australia
[3] Univ Hosp Geneva, Infect Control Programme, Rue Gabrielle Perret Gentil 4, CH-1205 Geneva, Switzerland
[4] Univ Hosp Geneva, Div Infect Dis, Rue Gabrielle Perret Gentil 4, CH-1205 Geneva, Switzerland