[1] Univ Lund, Dept Paediat, Malmo Univ Hosp, S-20502 Malmo, Sweden
[2] Univ Lund, Dept Bacteriol, Malmo Univ Hosp, S-20502 Malmo, Sweden
[3] Univ Gothenburg, Dept Paediat, Gothenburg, Sweden
[4] Linkoping Univ, Dept Paediat, Linkoping, Sweden
[5] Umea Univ, Dept Paediat, Umea, Sweden
[6] Uppsala Univ, Dept Paediat, Uppsala, Sweden
[7] Karolinska Hosp, Dept Paediat, S-10401 Stockholm, Sweden
[8] Huddinge Hosp, Stockholm, Sweden
[9] Cent Hosp, Halmstad, Sweden
[10] Cent Hosp, Orebro, Sweden