Previous hepatitis B virus infection is associated with worse disease stage and occult hepatitis B virus infection has low prevalence and pathogenicity in hepatitis C virus-positive patients.
Giannini E, Ceppa P, Botta F, Fasoli A, Romagnoli P, Ansaldi F, Durando P, Risso D, Lantieri PB, Icardi GC, et al. Liver Int. 2003 Feb; 23(1):12-8.