[1] Nagoya Univ, Sch Med, Dept Pediat, Showa Ku, Nagoya, Aichi 4618673, Japan
[2] Nagoya Univ, Sch Med, Dept Hlth Sci, Showa Ku, Nagoya, Aichi 4618673, Japan
[3] Nagoya Univ, Sch Med, Res Inst Dis Mech & Control, Lab Virol,Showa Ku, Nagoya, Aichi 4668550, Japan
[4] Ekisaikai Gen Hosp, Dept Pediat, Nagoya, Aichi 4548052, Japan
[5] Fujita Hlth Univ, Sch Med, Dept Pediat, Toyoake, Aichi 4701192, Japan