Occult hepatitis B virus among chronic liver disease patients in Yemen

Objective: To estimate the rate of occult hepatitis B virus (HBV) among patients with chronic liver disease (CLD). Methods: After an informed consent, sera samples were collected during April 2004 to April 2005 from 280 patients (200 male and 80 female). They were previously diagnosed with CLD based on history and ultrasound and were investigated for occult HBV infection. Sera were first screened for HBsAg and those which showed negative were tested for anti-HBc. The anti-HBc positive sera were further tested for anti-HBs to identify sera with isolated anti-HBc which in turn were subjected to HBV-DNA testing using PCR to determine the rate of occult HBV infection. Moreover, sera with occult HBV were tested for Anti-HCV and HCV-RNA using RT-PCR. Results: HBsAg was detected in 44 of 280 (15.7%). Of 236 HBsAg negative sera anti-HBc was detected in 22 (9.3%). All anti-HBc positive sera were found to be anti-HBs negative. HBV-DNA was detected in 11 of 22 (50.0%) sera with isolated anti-HBc indicating occult HBV in 4.3% of all sera. None of the sera with occult HBV had anti-HCV or HCV-RNA. Conclusions: Occult HBV infection does exist among CLD patients in Yemen and the mechanism of its occurrence merits further investigation.