[1] Tsukuba Mem Hosp, Dept Emergency & Crit Care Med, 1187-299 Kaname, Tsukuba, Ibaraki 3002622, Japan
[2] Univ Tsukuba, Fac Med, Dept Hlth Serv Res, Tsukuba, Ibaraki 3058577, Japan
[3] Kumamoto Univ, Joint Res Ctr Human Retrovirus Infect, Div Mol Virol & Genet, Kumamoto 8600811, Japan
[4] Muribushi Okinawa Ctr Teaching Hosp, Dept Med, Okinawa 9012132, Japan
[5] Univ Tokyo, Inst Med Sci, Div Syst Virol, Minato Ku, Tokyo 1088639, Japan
[6] Univ Tokyo, Grad Sch Frontier Sci, Kashiwa, Chiba 2778561, Japan
[7] Juntendo Univ, Dept Gen Med, Tokyo 1138421, Japan