1, previous medical history; 2, liver and spleen palpation; 3. Skin examination; 4, chest X-ray or radiography, in addition to the new and temporary staff, should be checked every other year; 5, dysentery, typhoid fever with bacteria inspection; 6, clinical suspicion or a history of other intestinal infectious diseases within one year, need to do the corresponding laboratory examination; 7. HAV-IgM and HEV-IgM should be checked if alanine aminotransferase is abnormal during liver function examination.