Hepatitis C genotypes and subtypes in Saudi Arabia.

Hepatitis C virus (HCV) genotypes are diverse geographically. Infectivity, pathogenicity, and sustained response to treatment may be influenced by HCV genotypes/subtypes. This study examined the relative distribution of hepatitis C genotypes and subtypes among isolates from 84 individuals with chronic active hepatitis (CAH), 39 haemodialysis patients, and 31 intravenous drug addicts, of Saudi Arabian origin. Reverse transcription-polymerase chain reaction (RT-PCR) using specific primers from the 5'-UTR was performed and amplified products were genotyped/subtyped using a commercial reverse phase hybridisation technique (Innolipa HCV 11, Innogenetics, Belgium). Seventy-four percent of the CAH patients were found to be genotype 4 (4c/4d: 33%; 4h: 14%; 4e: 7%; 4: 20%) but other subtypes such as 1b: 14%, 2b: 4%, 3a: 5%, 5a: 1%, and 6a: 1%, were also detected. A history of blood transfusion was disclosed in only 10% of the CAH group. The pattern among haemodialysis patients was as follows: genotype 4: 49% (4h: 13%; 4: 36% ); 1a: 33%, 1: 3%; 1b: 10%; and 5a: 5%. The intravenous drug addict group showed 39% subtype 1b, but other subtypes such as 9% for 1a; 3% for 2a; 36% for 4; 3% for 5a; and 9% for 3a were seen. It is concluded that genotype 4 is predominant among our HCV isolates from CAH patients but subtype 1a and 1b have emerged among our haemodialysis and intravenous drug addict cases, respectively. A significant relationship between the viral genotype and the source of infection has emerged among Saudi groups at high risk for hepatitis C virus.