What antigen marker is most closely associated with the transmissibility of HBV infection?

The antigen marker most closely associated with the transmissibility of Hepatitis B virus (HBV) infection is HBeAg. This antigen appears following the presence of Hepatitis B surface antigen (HBsAg) and is considered a marker of viral replication and infectivity. High levels of HBeAg indicate that the virus is actively replicating in the body, which correlates with a higher risk of transmitting the virus to others.

Individuals who test positive for HBeAg are more likely to spread the virus compared to those who are HBeAg-negative, as the latter may have a lower level of viral load or be in a phase of the infection where the virus is not actively replicating. Monitoring HBeAg can help in understanding the infectivity risk of individuals infected with HBV.

The other antigen markers and antibodies are significant in the context of HBV infection and immunity, but they do not directly correlate with the high transmissibility of the virus as HBeAg does. For instance, HBsAg indicates active infection but does not necessarily imply high levels of viral replication and risk of transmission. HBcAg is primarily an intracellular marker and is not typically measured in the serum. Anti-HBc signifies a past or current infection but does not indicate