[1] Osaka City Univ, Grad Sch Med, Dept Publ Hlth, Osaka, Japan
[2] Osaka City Univ, Grad Sch Med, Res Ctr Infect Dis Sci, Osaka, Japan
[3] Kyoto Prefectural Univ Med, Grad Sch Med Sci, Dept Epidemiol Community Hlth & Med, Kyoto, Japan
[4] Juntendo Univ, Sch Med, Dept Pediat, Tokyo, Japan
[5] Yokohama City Univ, Dept Pediat, Med Ctr, Yokohama, Kanagawa, Japan
[6] Fukushima Med Univ, Sch Med, Dept Pediat, Fukushima, Japan
[7] Mie Natl Hosp, Dept Int Hlth & Pediat, Tsu, Mie, Japan
[8] Hirakata City Hosp, Dept Pediat, Osaka, Japan
[9] Tokyo Womens Med Univ, Sch Med, Dept Publ Hlth, Tokyo, Japan
[10] Niigata Univ, Grad Sch Med & Dent Sci, Dept Infect Dis Control & Int Med, Niigata, Japan
[11] Sapporo Med Univ, Sch Med, Dept Publ Hlth, Sapporo, Hokkaido, Japan
[12] Jichi Med Univ, Dept Publ Hlth, Shimotsuke, Japan
[13] Radiat Effects Res Fdn, Dept Epidemiol, Hiroshima, Japan
[14] Aichi Med Univ, Dept Pediat, Nagakute, Aichi, Japan
[15] Tokyo Med & Dent Univ, Grad Sch Med & Dent Sci, Dept Pharmacovigilance, Tokyo, Japan
[16] Kawasaki Med Sch, Dept Pediat, Okayama, Japan
[17] Tanabe Childrens Clin, Dept Pediat Neurol, Osaka, Japan
[18] Niigata Seiryo Univ, Sch Nursing, Niigata, Japan
[19] Osaka Prefectural Govt, Dept Publ Hlth & Med Affairs, Osaka, Japan
[20] Showa Univ, Dept Publ Hlth, Sch Med, Tokyo, Japan
[21] Coll Healthcare Management, Miyama, Japan
[22] Med Co LTA, Clin Epidemiol Res Ctr, Fukuoka, Japan