[1
]
Department of Gastroenterology, Peking University Third Hospital, Beijing, China.
[2
]
Department of Gastroenterology, Peking University Third Hospital, Beijing, China.
Electronic address: zhouliya123456@163.com.
[3
]
State Key Laboratory for Infectious Disease Prevention and Control, National Institute
for Communicable Disease Control and Prevention, Chinese Center for Disease Control
and Prevention, Beijing, China.