What could be the cause of chronic hepatitis b?

Virus at early age. Hep b: common (world-wide) viral infection, commonly obtained at birth from mom who is chronic carrier (probably got it at birth from her mother). Adult onset (usually blood transmission, less likely sexual): better chance of being only acute, not chronic. "dose" of exposure, genotype, immune response all play a role. Can rx. Chr inf can lead to more liver problems, incl. Cirrhosis, failure, ca.