Which marker is typically positive during the incubation period of hepatitis B?

The marker that is typically positive during the incubation period of hepatitis B is HBsAg (Hepatitis B surface Antigen). When a person is infected with the hepatitis B virus, HBsAg is one of the earliest markers to appear in the bloodstream as the virus begins to replicate.

During the incubation period, which lasts from the time of exposure to the virus until the onset of symptoms, HBsAg indicates an active hepatitis B infection. This marker is used clinically to diagnose hepatitis B because its presence demonstrates that the virus is present in the body, and the infection can be either acute or chronic.

In contrast, Anti-HBc (antibody to hepatitis B core antigen) typically appears after HBsAg during the acute phase of infection, and Anti-HBs (antibody to hepatitis B surface antigen) appears later, usually indicating recovery or immunity after resolution of infection. HBV DNA, which represent the viral load, can also be detected, but its clinical role is usually more specific to monitoring infection rather than as a primary marker during the early phase. Thus, HBsAg is the most definitive marker present during the incubation of hepatitis B infection.