[1] Taoyuan Gen Hosp, Dept Infect Dis, Minist Hlth & Welf, Taoyuan 330, Taiwan
[2] Natl Yang Ming Chiao Tung Univ, Inst Publ Hlth, Sch Med, Taipei 112, Taiwan
[3] Taoyuan Gen Hosp, Dept Nursing, Minist Hlth & Welf, Taoyuan 330, Taiwan
[4] Natl Yang Ming Chiao Tung Univ, Sch Clin Med, Taipei 112, Taiwan
[5] Taipei Med Univ, Sch Publ Hlth, Taipei 110, Taiwan