Hepatitis B virus quantification refers to the specific quantification of hepatitis B DNA. The level of hepatitis B virus quantification reflects how infectious the body is. A high quantification of hepatitis B virus is highly contagious, while a low quantification of hepatitis B virus is less contagious. A negative quantification of the hepatitis B virus often indicates that the virus is not actively replicating in the body. For people with hepatitis B virus, it is necessary to have regular hepatitis B virus quantification tests. For some people who are negative for hepatitis B surface antigen and positive for hepatitis B core antibody alone, it is also necessary to have quantitative tests for hepatitis B virus, because about 10% of the population may be hepatitis B virus carriers if they are positive for core antibody alone. If the quantitative virus test is negative, they are not carriers of hepatitis B virus. In addition patients who are receiving antiviral treatment should also have their hepatitis B virus quantified regularly to determine the effectiveness of treatment.