[1] Mackay Mem Hosp, Dept Pediat, Taipei, Taiwan
[2] Mackay Childrens Hosp, Taipei, Taiwan
[3] Mackay Med Coll, Dept Med, New Taipei, Taiwan
[4] Natl Cheng Kung Univ, Natl Cheng Kung Univ Hosp, Dept Pediat, Coll Med, Tainan, Taiwan
[5] Chang Gung Univ, Chang Gung Childrens Hosp, Dept Pediat, Coll Med, Taoyuan, Taiwan
[6] Kaohsiung Chang Gung Mem Hosp, Dept Pediat, Kaohsiung, Taiwan
[7] Chang Gung Univ, Coll Med, Kaohsiung, Taiwan
[8] Ctr Dis Control, Res & Diagnost Ctr, Dept Hlth, Atlanta, GA USA
[9] Natl Taiwan Univ Hosp, Dept Pediat, 8,Chung Shan South Rd, Taipei, Taiwan