[1] Natl Publ Hlth Inst, Dept Hlth Promot & Chron Dis Prevent, SF-00300 Helsinki, Finland
[2] Univ Tampere, Tampere Sch Publ Hlth, FIN-33101 Tampere, Finland
[3] Univ Helsinki, Dept Publ Hlth, Helsinki, Finland
[4] Natl Publ Hlth Inst, Dept Hlth & Funct Capac, SF-00300 Helsinki, Finland
[5] London Sch Hyg & Trop Med, Med Stat Unit, Dept Epidemiol & Populat Hlth, London WC1, England
[6] Univ Oulu, Dept Pediat, SF-90100 Oulu, Finland
[7] Univ Turku, Dept Pediat, Turku, Finland
[8] Juvenile Diabet Res Fdn Ctr Prevent Type 1 Diabet, Turku, Finland
[9] Juvenile Diabet Res Fdn Ctr Prevent Type 1 Diabet, Oulu, Finland
[10] Juvenile Diabet Res Fdn Ctr Prevent Type 1 Diabet, Tampere, Finland
[11] Univ Kuopio, Dept Clin Microbiol, FIN-70211 Kuopio, Finland
[12] Univ Turku, Immunogenet Lab, Turku, Finland
[13] Tampere Univ Hosp, Dept Pediat, Tampere, Finland
[14] Univ Helsinki, Hosp Children & Adolescents, Helsinki, Finland
[15] Tampere Univ Hosp, Res Unit, Tampere, Finland