[1] Saarland Univ, Inst Med Microbiol & Hyg, Ctr Infect Dis, Homburg, Germany
[2] Univ Bonn, Inst Hyg & Publ Hlth, D-53127 Bonn, Germany
[3] Univ Nebraska, Dept Internal Med, Div Infect Dis, Med Ctr, Omaha, NE USA
[4] Geneva Univ Hosp, Div Infect Dis, Fac Med, Geneva, Switzerland
[5] Geneva Univ Hosp, Fac Med, Ctr Clin Res, Geneva, Switzerland
[6] Univ St Andrews, Sch Med, Div Infect & Global Hlth Res, St Andrews, Scotland