1. Infectious Disease Office, Qingdao University, Qingdao City, Shandong Province, China.
2. Intensive Care Unit, Qingdao University, Qingdao City, Shandong Province, China.
3. Central Laboratory, Qingdao University, Qingdao City, Shandong Province, China.
4. Clinical Laboratory, Affiliated Hospital of the Medical College, Qingdao University, Qingdao City, Shandong Province, China.