According to the European Association for the Study of the Liver (EASL), an inactive hepatitis B virus (HBV) carrier state is defined as chronic HBV infection that has been present for at least 6 months, is associated with normal ALT (Alanine aminotransferase), undetectable or very low serum HBV DNA levels below 2000 IU/ml, and is HBeAg negative. An inactive carrier state indicates that the patient's body is able to fight off the infection but cannot do so completely. A small number of patients may develop progressive liver disease over time. Inactive carriers are not infectious. They can spread the virus to others through contact with infected blood or other bodily fluids though they will not know they are carrying the virus. Inactive carriers are treated the same as people who have healed from acute infection. They must be tested regularly for evidence of re-activation of the virus and any time there is exposure to blood or other bodily fluids they should be given preventive medication. People who have active hepatitis B may appear healthy but their livers could be suffering damage due to the presence of the virus. Their ALT levels may be high compared to an uninfected person. Active carriers can spread the virus through contact with infected blood or other bodily fluids. They should be treated just like people with acute infection or chronic hepatitis.