[1] Univ Zurich, Childrens Hosp, Div Infect Dis, CH-8032 Zurich, Switzerland
[2] Univ Zurich, Childrens Hosp, Div Oncol, CH-8032 Zurich, Switzerland
[3] Univ Bern, Childrens Hosp, Div Oncol, Bern, Switzerland
[4] Univ Bern, Inst Infect Dis, Bern, Switzerland
[5] Bioanalytica AG, Luzern, Switzerland