[1] St Jansdal Hosp, Dept Pediat, POB 138, NL-3840 AC Harderwijk, Netherlands
[2] TNO, Dept Child Hlth, NL-2301 CE Leiden, Netherlands
[3] Atrium Med Ctr, Dept Res & Innovat, NL-6401 CX Heerlen, Netherlands
[4] Natl Inst Publ Hlth & Environm RIVM, Lab Infect Dis & Perinatal Screening LIS, NL-3702 BA Bilthoven, Netherlands
[5] Maastricht Univ, Med Ctr, Dept Paediat Pulmonol, NL-6202 AZ Maastricht, Netherlands
[6] Atrium Med Ctr, Dept Paediat, NL-6401 CX Heerlen, Netherlands