[1] Division of Infectious Diseases and Clinical Epidemiology,
[2] Basel University Hospital,undefined
[3] Petersgraben 4,undefined
[4] 4031 Basel,undefined
[5] Switzerland e-mail: awidmer@uhbs.ch,undefined
[6] Department of Internal Medicine,undefined
[7] Liestal University Hospital,undefined
[8] Switzerland,undefined
[9] Division of Infectious Diseases,undefined
[10] Geneva University Hospital,undefined
[11] 1211 Geneva 14,undefined
[12] Switzerland,undefined
[13] Bacteriology Laboratory,undefined
[14] Basel University Hospital,undefined
[15] Petersgraben 4,undefined
[16] 4031 Basel,undefined
[17] Switzerland,undefined