[1] Peking Univ, Hosp 3, Dept Gastroenterol, Beijing 100191, Peoples R China
[2] Chinese Ctr Dis Control & Prevent, Natl Inst Communicable Dis Control & Prevent, State Key Lab Infect Dis Prevent & Control, Collaborat Innovat Ctr Diag & Treatment Infect Di, Beijing, Peoples R China
[3] Sun Yat Sen Univ, Affiliated Hosp 1, Dept Gastroenterol, Guangzhou 510275, Guangdong, Peoples R China
[4] Huazhong Univ Sci & Technol, Union Hosp, Tongji Med Coll, Div Gastroenterol, Wuhan 430074, Peoples R China
[5] Second Mil Med Univ, Changhai Hosp, Dept Digest Dis, Shanghai, Peoples R China