The presence of overlapping infection of HCV and HBV affects the prognosis of liver disease HCV infection in patients with chronic liver disease, especially dual infection of HBV and HCV, may accelerate the progression of liver disease. Viral hepatitis (viralhepatitis) is a group of infectious diseases caused by a variety of different hepatitis viruses, mainly liver damage, according to the pathogenic diagnosis, there are at least five types of hepatitis viruses, namely hepatitis A, B, C, D and E viruses, which cause viral hepatitis A, B, C, D and E, respectively, namely hepatitis A (hepatitis A), hepatitis B ( hepatitis B), hepatitis C), hepatitis D) and hepatitis E). Another type of hepatitis, called hepatitis G, is less common. How to check this symptom? 1, hepatitis A ① serum anti-HAVIgM positive in the acute phase. ②Double serum anti-HAV total antibody titers in the acute and recovery periods are 4-fold or more elevated. ③HAV particles were detected by immunoelectron microscopy in the stool in the acute early stage. The diagnosis of recent HAV infection is confirmed by a positive result of any of the above. ⑤ HAV RNA detected in serum or stool. 2. Hepatitis B (1) Current HBV infection: Diagnosis can be made with any one of the following. ①Serum HBsAg positivity. (2) Positive serum HBvDNA or positive HBVDNA polymerase. ③Serum anti-HBc-IgM positive. ④ Positive intrahepatic HVcAg and/or positive HBsAg, or positive HBVDNA. (2) Acute hepatitis B: Diagnosis can be made with one of the following dynamic indicators (1) HBsAg titer from high to low and anti-HBs positive after disappearance. (2) High titer of serum anti-HBc-IgM and low titer of anti-HbcIgG (I) or in the acute phase. (3) Chronic hepatitis B: clinically consistent with chronic hepatitis and more than one positive indicator of current HBV infection. (4) Chronic HBsAg carriers: those without any clinical signs or symptoms, with normal liver function and persistent positive serum HBsAg test for more than 6 months. 3, hepatitis C (1) exclusion diagnosis method: where does not meet the diagnostic criteria of viral hepatitis A, B, E, and except EBV, cytomegalovirus acute infection (specific IgM antibody negative) and other known causes of hepatitis, such as drug-related hepatitis, alcoholic hepatitis, epidemiology suggests non-oral infection, can be diagnosed as hepatitis C. (2) Specific diagnosis: those with positive serum anti-HCV or HCVRNA. 4. Hepatitis D Concurrent or overlapping infection with HBV: (1) Positive anti-HD-IgM in the serum, or positive anti-HD, or positive HDAg. (2) Positive HDVRNA in serum. (3) Positive HDAg in liver tissue. 5. Hepatitis E (1) Exclusion diagnosis method: Anyone with acute infection of hepatitis A, B, C, D, cytomegalovirus, EBV and other known causes, epidemiologically proven by oral infection, can be diagnosed as hepatitis E. (2) Specific diagnosis: serum anti-HEV-IgM positive in the acute phase, or HEV particles found by fecal immunoelectron microscopy in the acute phase, or anti-HEV negative in the acute phase but positive in the recovery phase.