[1] Jikei Univ, Dept Infect Dis & Infect Control, Sch Med, 3 Nishi-shinbashi,Minato Ku, Tokyo, Japan
[2] Tokyo Med & Dent Univ, Inst Integrated Hosp Adm, Tokyo, Japan
[3] Tokyo Healthcare Univ, Div Infect Prevent & Control, Postgrad Sch, Tokyo, Japan
[4] Int Univ Hlth & Welf, Sch Med, Dept Infect Dis, Narita, Japan
[5] Univ Tokyo, Inst Med Sci, Adv Clin Res Ctr, Div Infect Dis, Tokyo, Japan