A thiy-year man presented with nausea, fever and jaundice of 5 days duration. The biochemical tests revealed a bilirubin of 6.7 mg/d1 (conjugated 5.0 mg/dl) with SGOT/ SGPT (AST/ALT) of 1230/900 IU/mi. The serological tests showed presence of HBs Ag. IgM anti-HBc and Hbe Ag. The most likely diagnosis is: