1. Department of Emergency Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan
2. Division of Infectious Diseases, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan
3. Chang Gung University Medical College, Tao-Yuan 333, Taiwan
4. Department of Pediatric, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan