Occult hepatitis B virus infection (OBI) is characterized by the presence of HBV DNA in the liver tissue or
in the serum of HBsAg negative individuals. Although OBI was detected frequently in patients with chronic hepatitis C,
the clinical implication of this co-infection is still not fully clarified. The aim of the present study was to assess the
prevalence and the possible clinical impact of occult HBV infection in patients with chronic hepatitis C. A total of 60
chronic HCV patients who were HBsAg negative, were enrolled into the study. Serum samples from the studied
patients were tested for the presence of anti-HBs and total anti-HBc antibodies by ELISA technique and HBV DNA by
real time PCR assay. The results showed that 8 (13.3%) patients were HBV DNA positive; 6 (75%) patients were anti-
HBc positive while 3 patients (37.5%) were anti-HBs positive. There was no significant difference between chronic
HCV patients with or without HBV DNA in duration of infection, ALT level, histological score or HCV viral load. In
conclusion, a considerable proportion of patients with chronic hepatitis C had occult HBV infection. Occult HBV
infection was significantly higher among anti-HBc positive patients. Occult HBV infection did not seem to modify the
progression of chronic HCV-related liver disease.