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 fr om 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 Sau di Arabian healthy blood donors (n = 200) and patients with cryptogenic (no n-A-E) hepatitis (n = 71). After serum extraction and RNA reverse transcrip tion, amplification was carried out by the polymerase chain reaction (PCR), using primers for the 5' noncoding region (NCR), NS5A region and NS3 helic ase region. Among the patients with cryptogenic hepatitis, PCR-positivity w as 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 considere d 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 n oted that the positivity rate is not far different among the three amplifie d regions, indicating that the heterogeneity of GBV-C/HGV is not as extensi ve as in hepatitis C virus. Phylogenetic analysis of 5' NCR DNA sequences s howed that all isolates in this study belong to genotype 2. We conclude tha t the prevalence of GBV-C/HGV is similar to what is reported worldwide amon g the general Saudi population but relatively higher among Saudi patients w ith cryptogenic hepatitis.