Which marker is indicative of a chronic Hepatitis B carrier?

The marker that indicates a chronic Hepatitis B carrier is the presence of Hepatitis B e antigen (HBeAg). This antigen is a product of the replication of the Hepatitis B virus and is associated with higher levels of viral replication. When HBeAg is present, it suggests an active viral infection and often correlates with increased infectivity.

In chronic Hepatitis B infection, especially in carriers, the persistence of HBeAg can be a sign of ongoing viral replication and the active state of the disease. In contrast, the presence of antibodies to the e antigen (Anti-HBe) typically indicates a transition to a more inactive state of the virus, where the individual may become less infectious.

Markers such as Anti-HB core IgG and Anti-HB surface IgG are indicative of past exposure to the virus or a resolved infection but do not denote ongoing replication or chronic infection. Anti-HB e IgG suggests seroconversion (the change from HBeAg to Anti-HBe), indicating a decrease in viral activity rather than chronic carriage.

Thus, the identification of HBeAg is crucial in determining the activity of Hepatitis B and confirming if an individual is a chronic carrier.