[1] Korea Univ, Coll Med, Dept Internal Med, Div Infect Dis,Guro Hosp, 148 Gurodong Ro, Seoul 08308, South Korea
[2] Korea Univ, Dept Hosp Infect Control, Guro Hosp, Seoul, South Korea
[3] Korea Univ, Dept Hosp Infect Control, Anam Hosp, Seoul, South Korea
[4] Korea Univ, Dept Hosp Infect Control, Ansan Hosp, Ansan, South Korea
[5] Korea Univ, Coll Med, Dept Internal Med, Div Infect Dis,Anam Hosp, Seoul, South Korea
[6] Korea Univ, Coll Med, Dept Internal Med, Div Infect Dis,Ansan Hosp, Ansan, South Korea