[1] Princess Maxima Ctr Pediat Oncol, Heidelberglaan 25, NL-3584 CS Utrecht, Netherlands
[2] Univ Med Ctr Utrecht, Dept Med Microbiol, Utrecht, Netherlands
[3] Wilhelmina Childrens Hosp, Dept Pediat Infect Dis & Immunol, Utrecht, Netherlands
[4] Math Inst, Leiden, Netherlands
[5] Leiden Univ, Med Ctr, Leiden, Netherlands