1. Shaanxi Provincial Clinical Research Center for Hepatic & Splenic Diseases, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, People's Republic of China.
2. Department of Infectious Diseases, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, People's Republic of China.
3. National & Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, People's Republic of China.
4. Department of Biochemistry and Molecular Biology, Medical College of Xi'an Jiaotong University, Xi'an, People's Republic of China.
5. Department of Epidemiology and Health Statistics, School of Public Health, Medical College of Xi'an Jiaotong University, Xi'an, People's Republic of China.