[1] Korea Univ, Dept Emergency Med, Ansan Hosp, Ansan 15355, Gyeonggi Do, South Korea
[2] Korea Univ, Dept Internal Med, Ansan Hosp, Div Infect Dis, Ansan 15355, Gyeonggi Do, South Korea
[3] Natl Med Ctr, Natl Emergency Med Ctr, Seoul 04564, South Korea