1. Research Center, The Fourth Hospital of Hebei Medical University , Shijiazhuang, Hebei 050011 , China
2. Provincial Center for Clinical Laboratories, The Second Hospital of Hebei Medical University , Shijiazhuang, Hebei 050000 , China
3. Shijiazhuang Center for Disease Control and Prevention , Shijiazhuang, Hebei 050000 , China
4. Clinical College, Hebei Medical University , Shijiazhuang, Hebei 050020 , China
5. Department of Gastroenterology, The Second Hospital of Hebei Medical University , Shijiazhuang, Hebei 050000 , China