Changes in the Distribution of Hepatitis C Virus (HCV) Genotypes over the 1999-2010 Period in Northern Valladolid, Spain

Background: A retrospective analysis was carried out in all specimens from subjects with chronic hepatitis C sent for testing to our laboratory in Hospital Universitario Rio Hortega( Valladolid, Spain) over the period 1999-2009. The reason for this study was to examine the suggestion of other authors on the spread of genotype 4 strains. The objective was to describe the distribution of VHC genotypes in our geographical area and compare it with other state-wide reports. Methods: A total of 1074 patients were studied. Specimen preparation to isolate HCV RNA was carried out with the COBAS AmpliPrep system (Roche). Reverse transcription, amplification and reverse hybridization were performed with Qiagen and Siemens kits. Results: The most frequent HCV genotype was 1 (69%), followed by 3 (19,6%) and 4 (8.2%). The most frequent HCV subtype was 1b (41.3%). Most infections with genotype 4 (58%) were found among HCV-HIV-coinfected patients. From our previous report in 2002 to date (end December 2010), both an increase in the prevalence of genotypes 4 (from 7.3 to 8.8%) and 1 and 1a (from 25.9 to 29.4%) and a decrease in the prevalence of genotype 1b (from 44% to 39,5%) has been observed over time. Patients with genotype 4 were, mostly, men and with HIV-HCV coinfection. Conclusions: The prevalence of genotype 4 in our geographical environment was significantly different than the national average which leads to the conclusion that the spread of this genotype was much slower than suggested.