[1] Nagoya Univ, Grad Sch Med, Dept Virol, Showa Ku, Nagoya, Aichi 4668550, Japan
[2] Anjo Kosei Hosp, Dept Pediat, Anjo, Japan
[3] Nagoya Univ, Grad Sch Med, Dept Pediat, Nagoya, Aichi, Japan
[4] Okayama Univ, Grad Sch Med & Dent, Dept Pediat, Okayama, Japan
[5] Fujita Hlth Univ Coll, Dept Med Informat Technol, Toyoake, Aichi, Japan
[6] Fujita Hlth Univ, Sch Med, Dept Pediat, Toyoake, Aichi 47011, Japan