[1] Karolinska Hosp, Microbiol & Tumorbiol Ctr, Dept Clin Microbiol, S-17176 Stockholm, Sweden
[2] Comenius Univ, Sch Med, Dept Pediat, Bratislava, Slovakia
[3] Karolinska Hosp, Astrid Lindgrens Childrens Hosp, Stockholm, Sweden
[4] Karolinska Hosp, Dept Pathol, S-10401 Stockholm, Sweden