[1] Gunma Univ Hosp, Integrat Ctr Internal Med, Dept Allergy & Resp Med, 3-39-15 Showa Machi, Maebashi, Gunma 3718511, Japan
[2] Gunma Univ Hosp, Intens Care Unit, 3-39-15 Showa Machi, Maebashi, Gunma 3718511, Japan
[3] Gunma Univ Hosp, Infect Control & Prevent Ctr, 3-39-15 Showa Machi, Maebashi, Gunma 3718511, Japan
[4] Gunma Prefectural Inst Publ Hlth & Environm Sci, 378 Kamioki Machi, Maebashi, Gunma 3710052, Japan