Sources of hepatitis B infection: patients with acute hepatitis, patients with chronic hepatitis and carriers of hepatitis B virus. The main transmission route is blood transmission (blood transfusion and blood products), i.e. non-intestinal transmission or percutaneous transmission. The third is close contact transmission, such as transmission of hepatitis B virus through semen and vaginal secretions; the fourth is medical transmission, such as unsafe injections, failure to do “one person, one needle, one tube The fourth is medical transmission, such as unsafe injection, not to do “one person, one needle, one tube”, contaminated syringes and needles, etc. become the transmission of hepatitis B virus.