1, hepatitis A is generally more prevalent in children, all year round, but the incidence is high in autumn, winter and early spring; 2, the incidence of hepatitis B is more men than women, the incidence decreases after the age of 40, all year round, mostly epidemic; 3, hepatitis C is generally more prevalent in those who can often contact blood or blood products, the incidence is not seasonal, is epidemic; 4, hepatitis D can only develop on the basis of hepatitis B Hepatitis D can only develop on the basis of hepatitis B, so only those who have hepatitis B may have hepatitis D. Hepatitis D is not seasonal and is epidemic; 5. Hepatitis E generally occurs in young adults, and is higher in men than in women.