1. Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Department of Gastroenterology, Hangzhou, Zhejiang 310016, China
2. Institute of Gastroenterology, Zhejiang University, Hangzhou, Zhejiang 310016, China
3. Department of Infectious Diseases, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, China