GB virus C/Hepatitis G virus infection in Saudi Arabian blood donors and patients with cryptogenic hepatitis

Viral hepatitis is a common infection in the developing countries. Aside from Hepatitis A-E viruses, a novel hepatitis virus termed GBV-C, or HGV, was recently described. We have studied the prevalence of this virus among Saudi Arabian healthy blood donors (n = 200) and patients with cryptogenic (non-A-E) hepatitis (n = 71). After serum extraction and RNA reverse transcription, amplification was carried out by the polymerase chain reaction (PCR), using primers for the 5' noncoding region (NCR), NS5A region and NS3 helicase region. Among the patients with cryptogenic hepatitis, PCR-positivity was 18/71 (25.4%) for the 5' NCR, 14/71 (19.7%) for the NS5A region, and 15/71 (21.1%) for the NS3 helicase region. Among the healthy blood donors, PCR-positivity was 4/200 (2%) for the 5' NCR, 0/200 (0%) for the NS5A region, and 1/200 (0.5%) for the NS3 helicase region. Since the 5' NCR is considered the most conserved segment of the virus genome, it is not unusual to find higher positivity rate when that region is used for amplification. It is noted that the positivity rate is not far different among the three amplified regions, indicating that the heterogeneity of GBV-C/HGV is not as extensive as in hepatitis C virus. Phylogenetic analysis of 5' NCR DNA sequences showed that all isolates in this study belong to genotype 2. We conclude that the prevalence of GBV-C/HGV is similar to what is reported worldwide among the general Saudi population but relatively higher among Saudi patients with cryptogenic hepatitis.