[1] Natl Taiwan Univ Hosp, Dept Internal Med, 7 Chung Shan South Rd, Taipei 100, Taiwan
[2] Natl Taiwan Univ Coll Med, Dept Internal Med, Taipei, Taiwan
[3] Taipei Vet Gen Hosp, Dept Internal Med, Taipei, Taiwan
[4] China Med Univ Hosp, Dept Internal Med, Taichung, Taiwan
[5] Kaohsiung Chang Gung Mem Hosp, Dept Internal Med, Kaohsiung, Taiwan
[6] Natl Taiwan Univ Hosp, Infect Control Ctr, Taipei, Taiwan