Why to say some second liver blood carries bacterium not infectivity

It is not that there is no infectivity, but the infectivity is very low. The body fluids of hepatitis B patients will contain hepatitis B virus more or less, especially in the blood. However, the infectivity of hepatitis B virus is determined by the activity of the virus. After many patients are treated, the activity of the virus will be greatly reduced, and the infectivity will also be reduced.